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2007 Vol. 27, No. 10
Published: 2007-10-26
 
       光谱学与光谱分析
1905 Study of On-Line CCD Spectrum Data Acquisition System Based on CPLD
LI Gang1,WANG Yang1,2,LI Hai-lan1,LIN Ling1
The non-invasive detection blood component has being attracted significant interest in biomedical domain, where the method of near-IR spectroscopy is special. And the dynamic spectrum method can eliminate the main interference of the individual discrepancy and measure conditions. However, due to the requirement of excellent amplitude accuracy and high temporal resolution in spectrum data acquisition system, the CCD must have real time output, the data is large, and a high speed acquisition system is required. In the present paper a CCD data acquisition system based on CPLD is designed. The whole system is controlled by CPLD, which is used to supply CCD timing and controls signal disposal, transmission, sample rate and storage and transmission of data. The system structure is simplified and the speed is improved, and the system meets the requirements of time resolution.
2007 Vol. 27 (10): 1905-1909 [Abstract] ( 1682 ) PDF (1823 KB)  ( 658 )
1910 The Development and Applications of Atmospheric Pressure Matrix-Assisted Laser Desorption/Ionization
HUANG Zheng-xu1, GUO Chang-juan1, CHEN Hua-yong1, ZHOU Zhen1,2*
A kind of new ionization source, atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI), is introduced in the present paper. This ionization source was studied and developed on the basis of vacuum MALDI. It has been applied widely in the field of biomacromolecule. This ionization source has softer analyte ionization and produces fewer fragmentations compared with conventional vacuum MALDI. It works at atmospheric pressure, therefore eases to be coupled to mass spectrometers, acting as an external ion source, and greatly extends the application fields of MALDI. The principle, configuration and technical development of AP-MALDI are described detailedly. Moreover, the current applications and prospect of the device in analyzing biopolymers are summarized.
2007 Vol. 27 (10): 1910-1916 [Abstract] ( 255 ) PDF (1504 KB)  ( 435 )
1917 A Measurement of Spontaneous Magnetic Field by Satellites Structures of Harmonic Spectrum
WANG Guang-chang1,2, CHEN Tao1, ZHANG Ting1, DENG Li1, ZHENG Zhi-jian2
The satellites structures of doubling harmonic spectrum and tripling harmonic spectrum were measured at the reflection direction of laser wave from the front side of targets, employing OMA optical multi-channel spectrometer during the interactions of femtosecond laser with solid targets. The satellites structures of red-shift harmonic spectrum of 2ω0 and 3ω0 were observed. Under the intensity of ～1018 W·cm-2, the result of measurement indicates that the spontaneous magnetic field was all less than 1 MGs level by analyzing the satellites structures of doubling harmonic spectrum and tripling harmonic spectrum during the laser-plasma interaction. With increasing the intensity of the laser pulse, the peak of the red-shift moves further to the long wavelength side causing the broadening of the spectrum. The measurements of the spontaneous magnetic field provide a basis of diagnosing the movement of the critical surface in the laser-plasma interaction process.
2007 Vol. 27 (10): 1917-1920 [Abstract] ( 568 ) PDF (1329 KB)  ( 589 )
1921 Crop Geometry Identification Based on Inversion of Semiempirical BRDF Models
HUANG Wen-jiang1,3, WANG Jin-di2, MU Xi-han2, WANG Ji-hua1, LIU Liang-yun1, LIU Qiang3,NIU Zheng3
Investigations have been made on identification of erective and horizontal varieties by bidirectional canopy reflected spectrum and semi-empirical bidirectional reflectance distribution function(BRDF) models. The qualitative effect of leaf area index (LAI) and average leaf angle (ALA) on crop canopy reflected spectrum was studied. The structure parameter sensitive index (SPEI) based on the weight for the volumetric kernel (fvol), the weight for the geometric kernel (fgeo), and the weight for constant corresponding to isotropic reflectance (fiso), was defined in the present study for crop geometry identification. However, the weights associated with the kernels of semi-empirical BRDF model do not have a direct relationship with measurable biophysical parameters. Therefore, efforts have focused on trying to find the relation between these semi-empirical BRDF kernel weights and various vegetation structures. SPEI was proved to be more sensitive to identify crop geometry structures than structural scattering index (SSI) and normalized difference f-index (NDFI), SPEI could be used to distinguish erective and horizontal geometry varieties. So, it is feasible to identify horizontal and erective varieties of wheat by bidirectional canopy reflected spectrum.
2007 Vol. 27 (10): 1921-1924 [Abstract] ( 1954 ) PDF (1076 KB)  ( 602 )
1925 Ion Mobility Spectrometry for the Isomeric Volatile Organic Compounds
HAN Hai-yan, JIA Xian-de, HUANG Guo-dong, WANG Hong-mei, LI Jian-quan, JIN Shun-ping, JIANG Hai-he, CHU Yan-nan*, ZHOU Shi-kang
Ion mobility spectrometry (IMS) is based on determining the drift velocities, which the ionized sample molecules attain in the weak electric field of a drift tube at atmospheric pressure. The drift behavior can be affected by structural differences of the analytes, so that ion mobility spectrometry has the ability to separated isomeric compounds. In the present article, an introduction to IMS is given, followed by a description of the instrument used for the experiments to differentiate isomeric compounds. Positive ion mobility spectras of three kinds of isomeric volatile organic compounds were studied in a homemade high-resolution IMS apparatus with a discharge ionization source. The study includes the differences in the structure of carbon chain, the style of function group, and the position of function group. The reduced mobility values were determined, which are in very good agreement with the previously reported theoretical values using neural network theory. The influence of the structural features of the substances and including the size and shape of the molecule has been investigated. The reduced mobility values increases in the order: alcohols-1.
2007 Vol. 27 (10): 1925-1928 [Abstract] ( 1457 ) PDF (1589 KB)  ( 564 )
1929 The Electrical Conductivity of Triggered Lightning Channel
ZHANG Hua-ming1,3,YUAN Ping1,2*,SU Mao-gen1,Lü Shi-hua2
Spectra of return strokes for artificial triggered lightning were obtained by optical multi-channel analyzer (OMA) in Shandong region. Compared with previous spectra of natural lightning, additional lines of ArⅠ 602.5 nm and ArⅡ 666.5 nm were observed. Under the model of local thermodynamic equilibrium, electronic temperatures of the lightning channel plasma were obtained according to the relative line intensities. Meanwhile, with semi-empirical method the electron density was obtained by Hα line Stark broadening. In combination with plasma theory, electrical conductivity of the lightning channel has been calculated for the first time, and the characteristic of conductivity for lightning channel was also discussed. The relation between the electrical conductivity of channel and the return stroke current was analyzed, providing reference data for further work on computing return stroke current. Results show that the lightning channel is a good conductor, and electrons are the main carrier of channel current. The brightness of artificial triggered lightning channel is usually higher than that of natural lightning, and its current is smaller than that of the natural lightning.
2007 Vol. 27 (10): 1929-1932 [Abstract] ( 2335 ) PDF (1151 KB)  ( 487 )
1933 Study on Spectral Property of Phase Transition of PcNi-VO2 Films
YUAN Hong-tao1, 2, FENG Ke-cheng3, ZHANG Xian-hui3
Highly oriented VO2 thin films were deposited on sapphire substrate and [C8H17O]8PcNi thin films were spin-coated onto VO2 thin films. The microstructure of VO2 thin films was studied with XRD. The phase transition was observed and the change in the optical properties of the PcNi/VO2 multilayer-films were investigated with infrared spectrometer. It was found that the mid-infrared transmittance of the complex films in the wavelength range 1.5 to 5.5 mm raised with PcNi coating. The thermochromism of PcNi/VO2 films did not changed compared with VO2 films and the transition temperature was the same as that of VO2. It can be anticipated that the optical limiting property of PcNi/VO2 films will be superior to that of VO2 thin films or PcNi thin films.
2007 Vol. 27 (10): 1933-1935 [Abstract] ( 1167 ) PDF (1078 KB)  ( 494 )
1936 Laser Photolysis Study on Photochemical Reactions in Mixed Solutions of [bmim][PF6] and Acetonitrile
XU Jing-jing, WU Guo-zhong, LONG De-wu, YAO Si-de
Laser flash photolysis study was carried out for the first time in the binary mixture of room-temperature ionic liquid (RTIL) and traditional organic solvent. Photochemical properties of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] and its binary mixed solutions with MeCN were investigated by laser photolysis technique at an excitation wavelength of 355 nm, using anthraquinone (AQ) as a probe molecule. It was indicated that [bmim][PF6] itself participates in the reaction with 3AQ*. Moreover, along with the change in the ratio of RTIL to organic solvent, the decay reaction rate constant of 3AQ*changes regularly and a critical point was observed at xRTIL=0.06. Before the critical point, the decay rate constant increases rapidly with increasing xRTIL; however, it decreases obviously with increasing xRTIL after the critical point. The kinetic data are given, and the possible reaction mechanisms in mixed solutions are also speculated.
2007 Vol. 27 (10): 1936-1938 [Abstract] ( 1580 ) PDF (1305 KB)  ( 525 )
1939 Study on the Characteristics of Dielectric Barrier Discharge at Atmospheric Pressure by Spectroscopic Method
LI Xue-chen, LIU Zhi-hui, JIA Peng-ying, LI Shu-feng
In the present paper, stable discharges were respectively obtained in air and helium at atmospheric pressure with a dielectric barrier discharge device consisting of water electrodes. By comparing the discharges in the two gases, it was found that the discharge in air at atmospheric pressure is not uniform and micro-discharges can be discerned which are distributed on the electrode stochastically, while the discharge in helium at atmospheric pressure is quite uniform and no discharge filament can be discerned. Comparing the two kinds of discharges, the plasma generated in helium discharge at atmospheric pressure has better prospect for application in industry because of its uniformity. The discharge current waveforms in air and helium at atmospheric pressure were compared, and the results show that the discharge current pulses in air are stochastically distributed in time, while the current pulses in helium discharge appear periodically. The discharge duration in helium is much longer than that in air at atmospheric pressure. The discharge pulse length is about tens of nanoseconds in air and is about one microsecond in helium. Meanwhile the spectra emitted from the two kinds of discharges were studied, and the results show that the spectral line of 391.4nm emitted from N+2(B2Σ+u→X2Σ+g) is quite strong in helium discharge. On the contrary, the strength of 391.4nm spectral line is very weak in air discharge. These experimental results are significant for the realization of uniform discharge at atmospheric pressure and industrial application of dielectric barrier discharge.
2007 Vol. 27 (10): 1939-1941 [Abstract] ( 2024 ) PDF (1638 KB)  ( 581 )
1942 Explanation of CO of Acetone Changing in Solvents by Some Models
HUANG Bao-kun, REN Chun-nian, LI Zuo-wei*, LI Zhan-long, LI Zhao-kai, LU Guo-hui
Raman spectra of acetone’s carbonyl stretching in 16 solvents were measured, and were also calculated by self-consistent reaction field (SCRF) method in Gaussian03. The frequency shift in experiment was analyzed by donor-acceptor model, Kirkwood model and SCRF model respectively. Among them, the donor-acceptor model can explain the shift very well. The SCRF method can do it also, while not as well as the donor-acceptor model, but is better than Kirkwood model. Correlating the mechanisms of the 3 methods, it was found that the donor-acceptor model is powerful in explaining the vibrational spectra of molecular bond, which is nucleophilic reagent. The SCRF model considers not only the influence of dielectric constant ε, but also the influence of the bulk and the structure of molecule etc. Although the model is complex and difficult to calculate, but it takes many factors into account, so the calculated results accord with experiment better than the Kirkwood model. The main parameter of the Kirkwood model is ε, so it is very simple and easy to calculate, nonetheless the trend of frequency shift can still be reflected, indicating that the dielectric constant ε is a main character affecting the frequency shift.
2007 Vol. 27 (10): 1942-1944 [Abstract] ( 1254 ) PDF (1077 KB)  ( 527 )
1945 The Enhancement and Inhibition of Lucigenin Chemiluminescence by Phenol and Aniline Derivatives
SHI Ming-juan,Aung Myint, DONG Yong-ping,CUI Hua*
The effect of phenol and aniline derivatives on the lucigenin-H2O2-Co2+ chemiluminescence (CL) at different pH was studied. In NaHCO-Na2CO3 medium, some compounds enhanced the lucigenin CL while others inhibited the lucigenin CL. In NaOH medium, all tested compounds inhibited the lucigenin CL. It was found that the magnitude of enhancement and inhibition by tested compounds was related to their molecular structures, media, and pH. The fluorescence spectra of the system after the CL reaction and the CL spectra of the lucigenin system were studied. The possible mechanisms for CL enhancement and inhibition have been proposed. On the one hand, the competition of phenol and aniline derivatives with lucegenin for H2O2/HO-2 led to the inhibition. On the other hand, the nucleophilic adducts of lucigenin formed by the reactions of some phenol and aniline derivatives with lucegin reacted with lucigenin to give rise to lucigenin radicals, followed by the reactions with the dissolved oxygen to give CL, resulting in the enhancement. The competition of these two routes led to the CL enhancement or inhibition under different conditions.
2007 Vol. 27 (10): 1945-1950 [Abstract] ( 1665 ) PDF (1389 KB)  ( 621 )
1951 Study on Effect of Heating Rate on Thermal Decomposition of HMX Energetic Materials by In-Situ Diffuse Reflection FTIR Spectrum
LIUXue-yong, WANGLin, ZHENGMin-xia, JIANGYan, LUOYi-wei
In-situ FTIR spectroscopy is a rising and dynamic technique. This technique combines the advantages of investigation in-situ and accurate structure analysis by FTIR spectroscopy, and can detect real time chemical change in materials at different temperatures and obtain the relationship between micromechanism of materials and temperature. In the present paper, thermal decomposition of octahydro-1，3，5，7-tetranitro-1,3,5,7-tetrazocine (HMX) heated with a rate of 5, 10, 20 and 40 ℃·min-1, respectively, was investigated by in-situ diffuse reflection FTIR spectroscopy. The results demonstrate that intramolecular cyclization occurs in breakage of HMX with a heating rate of 5℃·min-1, while intermolecular cyclization appears with a heating rate of 10, 20 and 40 ℃·min-1. With increasing temperature, the rupture rate of C—N bond is faster than that of N—N bond, which verifies that the cleavage of C—N bond is the dominant rupture form. With increasing heating rate, the decomposition beginning temperature of C—N bond increases. Eight kinds of gaseous products such as CO2, N2O, CO, NO, HCHO, HONO, NO2 and HCN were determined. The decomposition mechanism of HMX was not affected with changing heating rate.
2007 Vol. 27 (10): 1951-1954 [Abstract] ( 1628 ) PDF (1751 KB)  ( 606 )
1955 LLE-PLS Nonlinear Modeling Method for Near Infrared Spectroscopy and Its Application
YANG Hui-hua1,2, QIN Feng2, WANG Yong1,3, WU Yun-ming4, SHI Xiao-hao4, LIANG Qiong-lin1, WANG Yi-ming1, LUO Guo-an1,3*
The traditional near infrared (NIR) spectra modeling algorithm-partial least squares (PLS) can’t effectively reflect the nonlinear correlations existing between the near infrared spectra and the chemical or physical properties of samples. Locally linear embedding (LLE) is a newly proposed nonlinear dimension reduction algorithm, which is a kind of manifold learning algorithm. It can find out the intrinsic dimension from high dimensional data effectively, and map the high dimensional input data points to a global low dimensional coordinates while keeping the spatial relations of the adjacent points, i.e. the geometry structure of the high dimensional space. No application of LLE in the information processing of NIR spectra has been reported. By combining LLE and PLS, a novel nonlinear modeling method LLE-PLS for NIR spectra was proposed. In the proposed method, LLE and PLS were adopted to deduct the dimensions of NIR spectra and build regressor, respectively. The LLE-PLS method was applied to correlate the NIR spectra with the concentrations of salvia acid B in the elution of column chromatography of Salvianolate. The results showed that LLE-PLS outperformed other preprocessing methods such as multiplicative scattering correction, the 1st derivative, vector normalization, minimum-maximum normalization, detrend, debias, and the 2nd derivative. After parameter optimization, LLE-PLS can accurately predict the concentration of salvia acid B, with a minimum RMSECV of 0.128 mg·mL-1 and r2 of 0.998 8, suggesting that LLE-PLS is better than PLS in modeling and prediction. The parameter of the number of nearest neighbor k of LLE-PLS and output dimension d can affect the performance of the method. The research showed that k is robust to RMSECV, and an excessively low or high output dimension d will result in a greater error because of insufficient or excessive information extraction. It can be concluded that LLE-PLS can effectively model the nonlinear correlations between spectra and physicochemical properties of the samples. And it is feasible to actualize online monitoring of the process of column chromatography of Salvianolate by coupling NIR spectra with LLE-PLS modeling method.
2007 Vol. 27 (10): 1955-1958 [Abstract] ( 2533 ) PDF (1373 KB)  ( 562 )
1959 Identification Model of Cultivated and Wild Chinese Medical Herbs Erigeron Breviscapus with Near-Infrared Spectroscopy
LI Guo-hui1,ZHANG Lu-da1*,YANG Jian-wen2,WANG Dong1, LIU Fang1, ZHAO Li-li3
Forty three cultivated and wild Chinese medical herbs erigeron breviscapus were scanned on two Fourier transform near-infrared spectroscopy instruments. Twenty samples were used to set up the BP-NN models and the others were used to validate the models. Fifteen principal components，whose variance contribution rate is above 99%，were collected as input nodes for BP-NN models. The correct identification rates of calibration samples were 100% for the models on both the two instruments, and the correct identification rates of validation samples were 100% and 95.7%, irrespectively. The results showed that using NIR to fast detect cultivated and wild Chinese medical herbs erigeron breviscapus was feasible.
2007 Vol. 27 (10): 1959-1961 [Abstract] ( 1488 ) PDF (1049 KB)  ( 544 )
1962 Study on Estimation of Postmortem Interval Using FTIR in Rat Lung
HUANG Ping1,TIAN Wei-ping1, 2,YANG Guang-de3,TUO Ya1,2,WANG Zhen-yuan1*
Fourier transform infrared spectroscopy (FTIR) was applied to study the decomposition process postmortem in rat lung tissue and provided a new method for the estimation of postmortem interval (PMI). The results demonstrated that, with the PMI increasing, the peak position of main absorbance bands showed no significant difference, but there was obvious variance of intensity: (1) The intensity of 1 080 and 1 241 cm-1 related to nucleic acid tended to decrease. (2) The intensity ratio at Amide Ⅰ(I1647) and Ⅱ(I1541) decreased since death. The intensity of 1338 and 1313cm-1 increased lightly. (3) The intensity at 1460, 1400 and 1170 cm-1 showed no significant difference. (4) A new band at 1120 cm-1 appeared since 72h after death and its intensity increased from 72 to 144 h postmortem. The authors’ preliminary results suggest that it may be possible for FTIR to become an effective method to estimate the PMI in forensic practice.
2007 Vol. 27 (10): 1962-1965 [Abstract] ( 2509 ) PDF (1328 KB)  ( 423 )
1966 Spectrum Characterization and Fine Structure of Copper Phthalocyanine-Doped TiO2 Microcavities
LIU Cheng-lin1,2, ZHANG Xin-yi2, ZHONG Ju-hua3, ZHU Yi-hua3, HE Bo4, WEI Shi-qiang4
Copper phthalocyanine-doped TiO2 microcavities were fabricated by chemistry method. Their spectrum characterization was studied by Fourier transform infrared (FTIR) and Raman spectroscopy, and their fine structure was analyzed by X-ray absorption fine structure (XAFS). The results show that there is interaction of copper phthalocyanine (CuPc) and TiO2 microcavities after TiO2 microcavities was doped with CuPc. For example, there is absorption at 900.76 cm-1 in FTIR spectra, and the “red shift” of both OH vibration at 3392.75 cm-1 and CH vibration at 2848.83 cm-1. There exist definite peak shifts and intensity changes in infrared absorption in the C—C or C—N vibration in the planar phthalocyanine ring, the winding vibration of C—H inside and C—N outside plane of benzene ring. In Raman spectrum, there are 403.4, 592.1 and 679.1 cm-1 characterized peaks of TiO2 in CuPc-doped TiO2 microcavities, but their wave-numbers show shifts to anatase TiO2. The vibration peaks at 1586.8 and 1525.6 cm-1 show that there exists the composite material of CuPc and TiO2. These changes are related to the plane tropism of the molecule structure of copper phthalocyanine. XAFS showed tetrahedron TiO4 structure of Ti in TiO2 microcavities doped with copper phthalocyanine, and the changes of inner “medial distances” and the surface structure of TiO2 microcavities.
2007 Vol. 27 (10): 1966-1969 [Abstract] ( 1851 ) PDF (1254 KB)  ( 631 )
1970 Effect of Temperature on the Secondary Structure of Fish Scale Collagen
ZHONG Zhao-hui, LI Chun-mei*, GU Hai-feng, DOU Hong-liang, ZHOU Li-ming
Pepsin-soluble collagen (PSC) was extracted from fish scale of grass carp and was analyzed by SDS-PAGE, which confirmed that PSC are typical type Ⅰcollagen and reach electrophoretic purity. Effect of temperature on the secondary structure of collagen was studied by FTIR, Raman and CD. FTIR indicated that the fish scale PSC had typically characteristic absorptions of collagen, and 1659, 1552 and 1238cm-1 were assigned to be amide Ⅰ, Ⅱ and Ⅲ respectively. When the temperature increased, amide A and amide B shifted to low frequency, the absorption of 1658cm-1 split into several absorption peaks, the absorption at 1552cm-1 had a slight red-shift followed by a distinct blue-shift, and the frequency of 1238cm-1 declined. Raman spectra showed that the absorptions of amideⅠ, amideⅡ and amide Ⅲ appeared at 1669, 1557 and 1245cm-1 respectively, which were higher than those in FTIR spectra. Furthermore, the characteristic absorptions of proline at 921 and 855cm-1 only appeared in Raman spectra. CD spectra demonstrated a rotatory maximum at 221.6nm and a negative peak at 204.4nm of PSC solution, which were typical spectral characteristics of the collagen triple helix structure. The structure changes of the lyophilized PSC appeared mainly between 35 and 60℃ in FTIR and Raman spectra, yet CD spectra demonstrated that the configurational changes of PSC in acidic solution appeared in the range of 20 to 35℃, indicating that the lyophilized PSC was more stable than the acidic solution of PSC.
2007 Vol. 27 (10): 1970-1976 [Abstract] ( 689 ) PDF (1998 KB)  ( 823 )
1977 Rapid Determination of Klason Lignin Content in Bamboo by NIR
LI Gai-yun1,HUANG An-min1,WANG Ge2,QIN Dao-chun2,JIANG Ze-hui1*
Lignin is one of the main components of lignocellulosic materials. The main purpose of wood cooking and bleaching is to remove lignin by chemical agent in paper industry. Whereas the lignin content shows wide variations depending on its tree specie, site condition, part and so on, it is essential to analyze the lignin content of different raw material. The aim of this paper is to develop a rapid near infrared (NIR) reflectance spectroscopic method to characterize the Klason lignin content of bamboo. Fifty four samples from three growth years, two positions along the longitudinal directions and three positions along the radial directions within a bamboo pole were prepared. The Klason lignin contents of 54 samples were analyzed according to traditional chemical method, the spectra of these samples were collected by NIR in the range of 350 to 2500 nm, and the relationship between the lignin content and the spectra of these samples was established by multivariate statistical technique. After second derivative pretreatment of raw spectra, the Klason lignin contents of the bamboo samples were quantified using partial least-squares statistical analysis (PLS1) and full cross validation in the range of 1011-1675 nm and1930-2488 nm. High coefficients of correlation (r) were obtained between the predicted NIR results and those obtained from traditional chemical method. The correlation coefficient of calibration model and prediction model was 0.99 and 0.97, respectively. The standard error of calibration (SEC) and standard error of prediction (SEP) was 0.36％ and 0.59％, respectively. It was found that the lignin content in bamboo could be determined rapidly with reasonable accuracy by the NIR method.
2007 Vol. 27 (10): 1977-1980 [Abstract] ( 1662 ) PDF (1136 KB)  ( 642 )
1981 Chemical Structure of Dicarboxylic Acids and Their Capacity Inhibiting of Calcium Oxalate Crystal Growth
DENG Sui-ping,HU Peng,OUYANG Jian-ming*
The effect of dicarboxylic acids with a three C—C bonds distance on the crystallization of calcium oxalate (CaOxa) was investigated in silica gel system by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). These acids include succinic acid, maleic acid, fumaric acid, malic acid, L-aspartic acid and tartaric acid. All the dicarboxylic acids can inhibit the aggregation of calcium oxalate monohydrate (COM) and induce the formation of calcium oxalate dehydrate (COD). But their ability to inhibit the growth and aggregation of COM, to diminish the specific surface area of COM and to induce COD formation were strengthened as the number of the substituted hydroxyl or amino group increased. The molecular mechanisms were discussed in terms of chemical structures of dicarboxylic acids. Only the dicarboxylic acids with a HOOC—CH(R)—CH2—COOH (ROH or NH2) group were found to have the best inhibitory effect on the CaOxa urinary stones. The results could provide some clue to looking for new drugs for urinary stones in clinic.
2007 Vol. 27 (10): 1981-1984 [Abstract] ( 1919 ) PDF (1777 KB)  ( 595 )
1985 Clustering Analysis Applied to Near-Infrared Spectroscopy Analysis of Chinese Traditional Medicine
LIU Mu-qing1,ZHOU De-cheng1,XU Xin-yuan2,SUN Yao-jie1,ZHOU Xiao-li1,HAN Lei1
The present article discusses the clustering analysis used in the near-infrared(NIR) spectroscopy analysis of Chinese traditional medicines, which provides a new method for the classification of Chinese traditional medicines. Samples selected purposely in the authors′ research to measure their absorption spectra in seconds by a multi-channel NIR spectrometer developed in the authors′ lab were safrole, eucalypt oil, laurel oil, turpentine, clove oil and three samples of costmary oil from different suppliers. The spectra in the range of 0.70-1.7 μm were measured with air as background and the results indicated that they are quite distinct. Qualitative mathematical model was set up and cluster analysis based on the spectra was carried out through different clustering methods for optimization, and came out the cluster correlation coefficient of 0.974 2 in the authors′ research. This indicated that cluster analysis of the group of samples is practicable. Also it is reasonable to get the result that the calculated classification of 8 samples was quite accorded with their characteristics, especially the three samples of costmary oil were in the closest classification of the clustering analysis.
2007 Vol. 27 (10): 1985-1988 [Abstract] ( 1141 ) PDF (1143 KB)  ( 678 )
1989 FTIR Spectra-Principal Component Analysis of Roots of Polygonum Cuspidatum from Different Areas
ZUO Kang, LI Dan-ting, GUO Shui-liang, CHEN Jian-hua*
Polygonum cuspidatum Sieb. et Zucc. is an important Chinese traditional medicine, and has wide distribution in China. Based on their infrared fingerprint spectra, Polygonum cuspidatum root samples from 7 geographical origins could be divided into 6 classes with principal component analysis. The classification was well correlated to their geographical origins and weather. In the same class, the chemical components of P. cuspidatum are similar to each other, which can be considered as the criterion for evaluating the quality of P. cuspidatum. The results showed that their characteristic infrared spectra were similar in the range of 4000-1700cm-1, but varied significantly for different groups and kinds of P. cuspidatum samples in the range of 1700-900cm-1. The method is rapid and simple, and could be applied to evaluate the quality of this traditional Chinese medicine. It is one of the methods in the quality control of traditional Chinese medicines.
2007 Vol. 27 (10): 1989-1992 [Abstract] ( 228 ) PDF (1245 KB)  ( 583 )
1993 Study of Temperature Correction in the PLS Near-Infrared Quantitative Analysis of the Wheat
LUO Chang-bing1,2, CHEN Li-wei3, YAN Yan-lu1,2, WANG Wen-zhen4, WANG Zhong-yi1*
The influence of sample temperature on the wheat PLS near infrared (NIR) quantitative analysis was studied with 45 wheat seeds. The original spectra of the wheat seeds were measured at different temperatures. The temperature corrections were subtracted from the original spectra of the samples by using the PLS algorithm. The corrected spectra were used to build the mathematical model of the near-infrared quantitative analysis of the wheat. The results show that the influence of sample temperature on the mathematical model can be eliminated effectively when the temperature correction was performed in the calculation, improving the stability and prediction of this mathematical model.
2007 Vol. 27 (10): 1993-1996 [Abstract] ( 560 ) PDF (1544 KB)  ( 595 )
1997 Study on the Corn Stover Lignin Oxidized by Chlorine Dioxide and Modified by Furfuryl Alcohol
SUN Yong1,2, ZHANG Jin-ping1,2, YANG Gang1,2, LI Zuo-hu1
The Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Visible), nuclear magnetic resonance spectroscopy (1H NMR) and TG analysis were used to study the oxidation of corn stover lignin by chloride dioxide and subsequently modified by furfuryl alcohol. The results were as following: The selective oxidation of lignin by chlorine dioxide was obtained by spectroscopy study. FTIR showed that the characteristic absorbance peaks of aromatic units were decreased after chloride dioxide oxidation. The increased absorbance for the band around 1720 cm-1 corresponding to carbonyl stretching was achieved in the oxidized lignin and the lignin modified with furfuryl alcohol. The ultraviolet-visible spectroscopy showed that the absorbance around 280nm was largely reduced after the lignin was oxidized. The 1H NMR spectroscopy also showed the decrease of aromatic units and methoxyl group in the oxidized lignin. All these indicated the formation of muconic acid and ester, or quinone derivatives when the lignin was selectively oxidized by chloride dioxide. The modification by furfuryl alcohol made the oxidized lignin more thermally stable.
2007 Vol. 27 (10): 1997-2000 [Abstract] ( 1723 ) PDF (1690 KB)  ( 604 )
2001 Near Infrared Determination of Sugar Content in Apples Based on GA-iPLS
LI Yan-xiao,ZOU Xiao-bo*,DONG Ying
To improve and simplify the prediction model of sugar content, genetic algorithm interval partial least square (GA-iPLS) methods, the evolution of iPLS described by Lars NΦrgaard, were proposed and used to establish the calibration models of sugar content against apple spectra. The apple spectra data were divided into 40 intervals, among which 5 subsets, i.e. No. 4, 6, 8, 11 and 18, containing 362 data points were selected by GA-iPLS. The optimum GA-iPLS calibration model was obtained with the correlation coefficient (rc) of 0.962, the root mean square error of cross-validation (RMSECV) of 0.334 6 and the root mean square error of prediction (RMSEP) of 0.384 6. Compared with the whole spectra data model, the data points and the factors in the GA-iPLS were decreased significantly. Consequently, the running time of the PLS model build by GA-iPLS was shorter than that of the whole spectra data model. Furthermore, the GA-iPLS model could not only improve precision, but also simplify the model.
2007 Vol. 27 (10): 2001-2004 [Abstract] ( 2546 ) PDF (1472 KB)  ( 688 )
2005 Determination of Four Contents of Feedstuff Powder Using Near Infrared Spectroscopy by PLS-BP Model
LIU Bo-ping1,2,QIN Hua-jun3,LUO Xiang2,4,CAO Shu-wen3 ,WANG Jun-de1*
Partial least squares (PLS) and artificial neural networks (ANN) prediction model for four components of feedstuff has been established with good veracity and recurrence. The spectra put into the model should be processed by second derivative and standard normal variate (SNV). Ten principal components compressed from original data by PLS and two peak values were taken as the inputs of Back-Propagation Network (BP)，while four predictive targets as outputs, according to Kolmogorov theorem and experiment, and twenty three nerve cells were taken as hidden nodes. Its training iteration times was supposed to be 10 000. Prediction deciding coefficient of four components by the model are 0.9950, 0.9980, 0.9990 and 0.9670, while the standard deviation of an unknown sample scanned parallelly are 0.027 74, 0.048 53, 0.032 92 and 0.022 04.
2007 Vol. 27 (10): 2005-2009 [Abstract] ( 2166 ) PDF (1607 KB)  ( 886 )
2010 New Technology for Sample Preprocessing in NIR Analysis
QIN Xi-yun1, LI Jun-hui2*, YANG Yu-hong1, CHANG Zhi-qiang2
Sample’s moisture content and granularity would have an important influence on NIR veracity. Preprocesssing methods have been used for NIR analysis to achieve better NIR veracity. With Yunnan flue-cured tobacco as study materials, the authors innovatively applied microwave fast drying technology and home pulverizer to tobacco preprocessing, which could finish the preprocessing in 5 min，faster than the traditional methods such as oven drying and sifting. Results showed that: microwave fast drying technology could improve NIR analysis veracity when samples’ moisture content had a wide range; influence of samples’ granularity on NIR veracity could be eliminated after 25 s home pulverizer shatter. This study can offer a new method for NIR analysis workers to simplify NIR preprocessing.
2007 Vol. 27 (10): 2010-2012 [Abstract] ( 2069 ) PDF (964 KB)  ( 918 )
2013 Application of Near-Infrared Spectroscopy to Management of Vegetation for Natural Grassland
XU Dong-mei1,2,WANG Kun1*
Vegetation is a major index for monitoring the grassland condition and productivity. The change in vegetation directly reflects degradation and restoration of grassland ecosystem. It is important to monitoring the information of vegetation changes to prevent degradation and realize sustainable development of grassland. Predication of vegetation was often completed by field investigation and laboratory analysis in the past, and could not satisfy the needs for inspecting of grassland degradation and restoration. Near-infrared spectroscopy (NIRS) is a rapid, convenient, high-efficiency, non-destructive and low-cost analytical technique, and has been widely used in various fields for quantitative and qualitative analysis. It has been one of the most important techniques for monitoring the succession of grassland ecosystem, and has great potential for applying in natural grassland management. Botanical composition is a major index of the vegetation community structure. The change in botanical composition indicates the developing stage of the plant community. Determining the botanical composition during vegetation succession can provide sound basis for establishing feasible measure of grassland management. NIRS can be successfully used as a rapid method to predict the grass, legume and other plant proportion in natural or semi-natural grasslands. The legume content in multi-species mixtures and the species composition in root mixtures can accurately be estimated by means of NIRS. Leaf/stem ratio of grass stands is an important factor affecting forage quality, diet selection, intake, and the intensity of photosynthesis. Estimates of leaf/stem ratios commonly are based on a labor intensive process of hand separating leaf and stem fractions. NIRS can be used successfully to predict leaf/stem ratios and mineral contents. The results of NIRS technique were well correlated with labor separating method. The decomposition of litter in grasslands is an important aspect of material cycle in grassland ecosystem. To study material cycling, especially mineral cycling in grassland ecosystems, it is essential to know the decomposition rate of the litter. NIRS technique can accurately predict the decomposition status of litter and the change of lignin, cellulose, nitrogen, ash and other nutrient contents during the decomposition of litter. NIRS has potential to provide rapid and effective estimates of material cycling in grassland ecosystems to assist managers in establishing application rates of grasslands that fall within productive and environmentally safe levels. The chemical composition of the plants in grassland is an important factor affecting herbivorous intake and material cycle, and is an important parameter in determining the status of degradation and restoration of grassland ecosystems. NIRS has been confirmed as a technique for reliably and accurately determining the dry matter, crude protein, acid detergent fibre, neutral detergent fibre, and certain microelement contents. With the development of spectral technique, the NIRS method will be more widely used in vegetation management.
2007 Vol. 27 (10): 2013-2016 [Abstract] ( 1782 ) PDF (923 KB)  ( 497 )
2017 Advance and Prospect of Spectroscopy Applied in Grassland Soil Inspection
SUN Yue-chun1,2,WANG Kun1*
Infrared spectroscopic measurement, especially near infrared spectroscopy, was widely used in grassland soil inspection. Recently, visible and ultraviolet diffuse reflectance spectroscopic techniques also were used in this field. Spectroscopy method is a rapid, timely, less expensive, non-destructive, straightforward analytic method. Furthermore, a single spectrum allows for simultaneous characterization of various soil properties and the techniques are adaptable for “on-the-go” field use. In the present paper, the authors reviewed the use of the techniques to inspect the water content, organic matter, nitrate content, available phosphorus, exchangeable potassium and soil texture classes of soil. The thermal infrared remote sensing assisted method for monitoring soil water content mainly includes thermal infrared method, thermal inertia method and temperature/vegetation index method. The content of organic material is strongly correlative with absorption features of soil spectrum in ultraviolet wave band (around 376, 795 nm), visible radiation wave band (around 616, 506 nm), and infrared wave band (around 724, 975 nm). Mid-infrared Fourier transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy could be used to determine nitrate concentration in soil pastes. When visible (Vis) (400-700 nm), near infrared (NIR) (700-2 500 nm) and mid infrared (MIR) (2 500-25 000 nm) were used to predict a number of different soil properties, more accurate predictions were obtained using the MIR for available phosphorus and electrical conductivity and the NIR produced more accurate predictions for exchangeable Al and K. Vis-NIR-FDA (the factorial discriminant analysis) is an efficient technique to classify soil into three main groups, sandy (light soils), loamy (medium soils), and clayey (heavy soils), and the classification models could be used for an on-the-go measurement system of soil properties. A standard penetrometer cone was modified to collect near-infrared reflectance and estimate soil moisture, density, and clay content. Because the techology can get useful soil datum, it can effectively improve grassland management. Nowaday a question that needs to be answered is how to examine the belowground biomass by the technique, so the authors can base on the data to forecast the grass growth. It is also needed to to invent more portable and “on-the-go” field use spectroscopy apparatus.
2007 Vol. 27 (10): 2017-2021 [Abstract] ( 1797 ) PDF (939 KB)  ( 594 )
2022 Survey of the Development of Near-Infrared Spectroscopy Instruments
QI Xiao, HAN Jian-guo*, LI Man-li
The technology of near-infrared spectroscopic analysis goes by the name of “superman” in the field of analytical chemistry. It is one of the most attention-attracting spectroscopic analysis technologies, and is developing rapidly nowadays. The first near-infrared spectroscopy (NIRS) instrument in the world is fifty years old. Although the authors only have a history of twenty years in NIRS instrument manufacturing, the achievements are exciting. The NIRS instruments are developing and emerging endlessly with the advancement of science. Firstly, the survey of the development of NIRS instruments is described in the present article. Secondly, the principles and the characteristics of five types of NIRS instruments are discussed, including interference filters, Fourier transform, acousto-optic tunable filter, and so on. In addition, the primary producers and their popular products are enumerated in the table. Finally, the direction of NIRS instrument development is viewed.
2007 Vol. 27 (10): 2022-2026 [Abstract] ( 2253 ) PDF (925 KB)  ( 626 )
2027 Synthesis and Characterization of Novel BrΦnsted Acidic Ionic Liquids
WU Qin1,2, DONG Bin-qi1, HAN Ming-han1*, ZUO Yi-zan1, JIN Yong1
Several water-stable BrΦnsted-acidic ionic liquids with an alkane sulfonic acid group were synthesized, and were characterized by nuclear magnetic resonance (NMR), infrared spectrum (IR), electrospray ionization mass spectrum (ESI-MS) and thermogravimetry (TG.). It was found that their structures were consistent with the designed one and all of their purities were more than 95%. These ionic liquids possess high thermal stability and wide liquid range, and their decomposition temperatures are higher than 300 ℃ by analyzing TG. In addition, they were found to have four kinds of ionic form, in which hydrogen ion can exist independently by analyzing ESI-MS. Moreover, the solubility of these ionic liquids was studied in some common solvents. All the ionic liquids are miscible with water and methanol, but are insoluble in ether, toluene and ethyl acetate.
2007 Vol. 27 (10): 2027-2031 [Abstract] ( 245 ) PDF (1887 KB)  ( 577 )
2032 Aliphatic Characteristics of the Fractions Isolated from the Soil Fulvic Acid Using XAD-8 Column
LIU Ben-ding, LI Xia, DAI Jing-yu*
In order to truly understand the character and structure of fulvic acid, which contains many substances, the authors isolated fulvic acid detailedly according to its definite character and its characteristic of similar structure. Fulvic acid with H+ can be adsorbed by the XAD-8 column balanced by the usual buffer(pH 2). The hydrophilic fraction in fulvic acid can be divided into three groups using the buffer with various pH (4.8, 7.0 and 11.0), while the hydrophobic fraction can be classified into two groups by the distilled water and alcohol separately. For FTIR(Fourier transform infrared) and NMR(nuclear magnetic resonance) spectroscopy analysis, three paddy soils were used. It may be concluded that the content of oxygen and carboxyl group dissolved at low pH is more than that dissolved in the water and alcohol, but the content of aliphatic fraction is less and has short side chain.
2007 Vol. 27 (10): 2032-2037 [Abstract] ( 587 ) PDF (1740 KB)  ( 451 )
2038 Micro-Raman Spectra for Gastritis and Gastric Ulcer Tissues
WANG Hui-min1, ZHANG Jin-yan1, GUO Jian-yu1, CAI Wei-ying1, SUN Zhen-rong1*, WANG Zu-geng1, FANG Min2, SUN Man-ping2, MA Shu-ying2
Micro-Raman spectroscopy was employed to identify gastritis tissues and gastric ulcer tissues. The primary spectral differences between the two types of samples include, for gastric ulcer tissues, (1) the intensity of the peak at 781 cm-1 ascribed to cytosine decreases, while the peaks ascribed to adenine and thymine respectively at 793 and 823cm-1 become stronger; (2) the bands of amide Ⅰ and amide Ⅲ at 1654 and 1320-1270cm-1 respectively, characteristic of α-helix structural protein, lose their intensities, and the tryptophan band at 1332cm-1 and phenylalanine band at 1003cm-1 reduced significantly, while the tryptophan marker at 1554cm-1 up shiftes to 1556cm-1 with increasing intensity; (3) a blue shift of 1073cm-1 line, the characteristic Raman band of lipid, and a reduction in the ratio of 1303 cm-1 assigned to in-phase CH2 twisting motion to 1268cm-1 from CH in-plane deformation were observed; (4)statistic analysis shows that the ratio of Raman intensities at bands 1449 cm-1 originating from CH2 group to 1660cm-1 from amideⅠ provides a promising standard to distinguish the two tissues.
2007 Vol. 27 (10): 2038-2041 [Abstract] ( 2576 ) PDF (1233 KB)  ( 481 )
2042 Study of the Raman Spectrum of CCl4 Fermi Resonance
GAO Shu-qin, HE Jia-ning, LI Rong-fu, ZUO Jian, LI Zhao-kai, HUANG Bao-kun, LI Zuo-wei
Fermi resonance is a very common phenomenon in molecule vibration spectra, especially in polyatomic molecule with complex structure. Fermi resonance appears when a fundamental vibration frequency lies closely to an overtone or combination frequencies. One can observe two peaks coming from Fermi resonance and the energy transfer also occurs between the two peaks. Fermi resonance phenomenon appears in both infrared spectrum and Raman spectrum. The Raman spectrum of CCl4 was measured. The frequency separation between the two peaks in a Fermi resonance doublet was observed and the integrated intensities were calculated with the software of OriginPro7.5. Fermi resonance interaction was caused by the CCl4 C-Cl f-symmetrical stretching fundamental ν03coupling. The combination frequency(ν1+ν4)of C-Cl a1-symmetrical stretching ν1 and band C-Cl2 f-symmetrical bending ν4 was calculated. Based on Bertran’s theory, Fermi coupling coefficient W was calculated and the theoretical value ν03of ν3 was estimated. The present article provided good reference for better understanding of the relationship between molecular vibration frequency and molecular structure.
2007 Vol. 27 (10): 2042-2044 [Abstract] ( 1554 ) PDF (1072 KB)  ( 980 )
2045 Surface-Enhanced Raman Spectra of Natural Tissue and Cancerous Tissue of Lung
LIU Yan-nan1,3,ZOU Zu-quan2,3,LIU Yan-qing4,XU Xiao-xuan1,3,YU Gang1,3,ZHANG Cun-zhou1,3
Surface-enhanced Raman spectra of natural tissue and cancerous tissue of lung from 300 to 1 700 cm-1 were measured. In the cancerous tissue of lung, the orderly conformations of amidesⅢ and amidesⅠof the main chains in protein such as α-helix，β-corner and no rules curly were damaged seriously; conversely, the extendable vibration of skeleton C—N and skeleton C—C increased. Side chains change became complicated. In general, the content of nucleic acids increases in the cancer tissue of lung. The lengthways conformations of lecithoid chains is out-of-order in the cancerous tissue of lung compared with the natural ones.
2007 Vol. 27 (10): 2045-2048 [Abstract] ( 719 ) PDF (1114 KB)  ( 663 )
2049 Study on Temperature Character of Stimulated Raman Scattering Spectrum in Silica Fiber
SUN Xiu-ping1,FENG Ke-cheng1,ZHANG Xi-he1,GAO Yang1,TAN Yong1,LIU Jian-guo2,LIU Weng-qing2
Stimulated Raman scattering (SRS) spectrum of silica fiber was studied under different temperatures. The influence of temperature on feature of SRS spectra was analyzed theoretically and experimentally. The laws of how the Raman frequency-shift, bandwidth and intensity of the first order Stokes light change with the temperature were obtained using a pulsed Q-switched doubled frequency laser. The experiments indicate that the frequency-shift becomes bigger with the increasing the temperature. Raman frequency-shift has a linear relationship with the temperature. Under the same pump power, when the temperature is lower, the order of SRS spectrum is lower. Lower temperature has high order Stokes light. For higher order Stokes lights, the lower the temperature, the higher the threshold. But the changes in spectrum bandwidth show no linear relationship with the temperature, and there is a maximum of bandwidth. Theory and experiments indicate that temperature has direct effect on the SRS of fiber.
2007 Vol. 27 (10): 2049-2052 [Abstract] ( 1438 ) PDF (1532 KB)  ( 703 )
2053 Comparison and Analysis of Laser Raman Spectra of Common Drinking Water
YANG Chang-hu,YUAN Jian-hui,ZENG Xiao-ying
In order to detect the drinking water quality in our country at the present time effectively, several brand brands of drinking water on the market and the distilled water that laboratory offered were measured and calculated. The laser Raman spectra of samples were measured，while the sample’s degree of degeneracy polarization at the symmetric stretching peak was calculated from the measurements. Results indicate that the relative intensity of the Raman spectrum and the degree of degeneracy polarization follow the same rule. Through comparison and analysis of the results of measurement and calculation, it is concluded that we can judge the relative content of mineral substance of drinking water by comparing the strengths of laser Raman spectrum characteristic peak and the magnitudes of the sample’s degree of degeneracy polarization at the same characteristic peak. This conclusion will provide us a new and effective path to assaying the quality of drinking water.
2007 Vol. 27 (10): 2053-2056 [Abstract] ( 1096 ) PDF (1540 KB)  ( 804 )
2057 Application of Raman Spectrometer (785 nm) to Jadeite Test
FANJian-liang, GUO Shou-guo, LIU Xue-liang
Jadeite is a greatly appreciated ge mstone and often referred to as “the king of jade”. Because of the advances in processing the treated jadeite is becoming more and more difficult for identification。NIR(785 nm)Raman spectrometer exhibits advantage of non-destruction, quickness, accurateness, and weak fluorescence interferences. This work reports such a research conducted using a NIR Raman spectrometer for a large number of jadeite samples. Based on the spectra collected and analysis there after performed, it is evident that the instrumentation and analysis methodology used have provided great information and assessment assistance in the application. It was found that the spectral response in the green area of a natural jadeite is much stronger in intensity than that in the white area. This is attributed to the key factor, the content of Cr3+ in the area. In contrast the spectral response in the green area of a treated jadeite is much weaker and additional Raman peaks start to show up on the high Raman shift side. This is the evidence of added fluorescence phenomenon and epoxyresin. It was also discovered that certain Raman features disappear compared to a natural sample. This indicates that the jadeite has been treated with acid and filled with colorless glue, which io turn destroyed the original exterior structure of a jadeite.
2007 Vol. 27 (10): 2057-2060 [Abstract] ( 212 ) PDF (1880 KB)  ( 772 )
2061 Adaptive Network-Based Fuzzy Inference System for the Forecast of Spectra
ZHANG Chi-jian,WANG Li
Because of the function of independent adaptation and study of NN and the best nonlinear speculating ability of fuzzy system, the adaptive network-based fuzzy inference system (ANFIS) which is composed of them absorbs their virtue. When applying it to the data analysis and model construction, the authors got the good nonlinear forecast by learning data, such as fluorescence spectrum. Fluorescence spectrometry is an important means of researching inside structure of molecule, which works easy, and features rapidness and high precision. So its forecast is more important. In the present paper, the authors utilize the spectra of the N2 to calculate, and prove that the means can forecast important spectrum information, the error is very small, less than 1.66 percent, which is conformed to meet the demand of the experiment. In short, the approach is workable.
2007 Vol. 27 (10): 2061-2063 [Abstract] ( 1627 ) PDF (1342 KB)  ( 515 )
2064 Effects of pH Value during Synthesis on the Structure and Performance of Ceria Zirconia Mixed Oxides
ZHAN Ying-ying, CAI Guo-hui, XIAO Yi-hong, ZHENG Qi*, WEI Ke-mei
Heating reflux aging technology was first applied to obtain a series of ceria zirconia mixed oxides composed of 0.6CeO2-0.4ZrO2. N2 physical adsorption, FT-Raman, and UV-Vis diffuse spectroscopy techniques were preformed to investigate the relationships between the structure and oxygen storage capacity of ceria zirconia mixed oxides prepared at different pH value of precipitation. The composition of ceria zirconia mixed oxides fluctuated with the pH value of precipitation, leading to the variation in phase ingredients, defects, crystallization and texture. Controlling the pH value of precipitation at 10.5-11.0 can avoid the introduction of Si, improve the texture, phase homogeneity and defects concentration, decrease the degree of crystallization, and increase the oxygen storage capacity.
2007 Vol. 27 (10): 2064-2068 [Abstract] ( 1788 ) PDF (1505 KB)  ( 499 )
2069 New Fluorescent Staining Method to Distinguish Normal and Malignant Rectum Tissues Using Terbium (Ⅲ)-Ciprofloxacin Complex
MENG Tao1,3,XU Duan-fu1,ZHAO Ying1,WANG Du-jin1,XU Yi-zhuang2*,QI Jian2,WU Jin-guang2
A new fluorescent staining method to distinguish normal and malignant rectum tissues using terbium(Ⅲ)-Ciprofloxacin complex was investigated. The terbium (Ⅲ) complex exhibits strong fluorescence and the staining process with the complex is very fast. It needs 3-5 minutes. The results showed that the fluorescence microscope images were similar to the images stained using traditional hematoxylin and eosin (H&E) methodology. The fluorescence spectra and FTIR spectra of normal and malignant rectum tissues were collected and the detection criterions for the malignant rectum tissues were the same as the staining results. In summary, the fluorescence staining may be developed as a simple and convenient method.
2007 Vol. 27 (10): 2069-2072 [Abstract] ( 1272 ) PDF (2037 KB)  ( 548 )
2073 Fluorescence Spectroscopy Study on Photobleaching Properties of Photosensitizers in Photodynamic Therapy
WANG Lei1, GU Ying1*, LI Xiao-song1, LIU Fan-guang1, YU Chang-qing2
The photobleaching and formation of photoproduct of hematoporphyrin monomethyl ether (HMME) was investigated in solution by fluorescence spectroscopy. Irradiation was performed by 532nm double-frequency Nd∶YAG laser at a fluence rate of 100 mW·cm-2, meanwhile the collection of fluorescence spectra was implemented an by optical multi-channel analyzer (OMA). Utilizing the basis spectra constructed and least-square fitting, the intensity of HMME fluorescence (613 nm), photoproduct fluorescence (639 nm) and autofluorescence can be resolved respectively from the single measured spectrum. The correlation between fluorescence intensity and the concentration of HMME is consistent with linear function at concentrations not exceeding 10 μg·mL-1. Monitoring the fluorescence spectroscopy during irradiation, three kinds of information were obtained, including photobleaching of HMME, formation and bleaching of photoproduct, as well as variation to fluorescence intensity due to the change of sample optical properties. Product generated by bleaching of photoproduct causes significant in sample optical properties. The implementation of fluorescence spectroscopy measurement and spectral analysis method presented here can be utilized effectively for both ex vivo investigation of photobleaching characteristics of photosensitizer and in vivo monitoring for dosimetry in photodynamic therapy.
2007 Vol. 27 (10): 2073-2078 [Abstract] ( 537 ) PDF (2318 KB)  ( 526 )
2079 Study on the Interaction of PTB and Serum Albumin by Fluorescence Method
CHEN Yan-hua1, BU Feng-quan1, HU Xiu-li1, LIU Zhi-qiang2, LIU Zhong-ying1*, LIU Jing-ying1, ZHOU Qiu-li1
A molecular spectroscopic investigation of the interaction of phenacyl thiazolium bromide (PTB) and bovine serum albumin (BSA) or human serum albumin (HSA) is reported employing fluorescence quenching techniques. It is determined that the maximal excitation wavelength is 280 nm for BSA solution, and 290 nm for HAS solution. When PTB was added into these solutions gradually, the emission peaks were decreased obviously, which are typical quenching phenomena. The results obtained reveal that there is a medium-intensity binding affinity for PTB with HSA and BSA. At 15 ℃, the binding constants of PTB and BSA(HSA) are 3.66×103 and 3.83×103, and the numbers of binding sites are 1.02 and 1.06 respectively. At 37 ℃, the binding constants of PTB and BSA(HSA) are 3.58×103 and 3.35×103, and the numbers of binding sites are 0.95 and 0.87 respectively. According to the thermodynamic parameters, the main sort of the binding force between the drug and BSA or HSA was electrostatic force. Based on the Fster non-radiation energy transfer theory, it could be acquired that the distance between BSA or HSA and PTB is 7.5 or 7.9 nm. According to the crystal structure of serum albumin, it can be speculated that subdomain ⅡA was the binding sites for the interaction of PTB and serum albumin, which is the region near Try214.
2007 Vol. 27 (10): 2079-2082 [Abstract] ( 581 ) PDF (1485 KB)  ( 523 )
2083 Determination of Chromphoric Dissolved Organic Matter in Water from Different Sources
LIU Xian-ping, LI Lei*, DAI Jin-feng, WANG Xiao-ru, Frank Lee S C
Chromophoric dissolved organic matter (CDOM) represents the fraction of the dissolved organic pool which absorbs light in the visible as well as UV ranges. It could affect the color of the waters. It is necessary to study it during in research on ecosystem, remote sensing of the water color and the cycle of carbon in waters. CDOM can fluoresce when excited, so fluorescence spectrum has been used to study its origin, distribution, and change.In the present article the fluorescence spectrophotometer was used to study the relation between the fluorescence intensity, spectrum area and the concentration of CDOM. When the concentration of CDOM is low(less than 75 mg·L-1), there is a better linear relationship(r2＞0.98)between the fluorescence intensity, the spectrum area and the concentration of CDOM. Meanwhile good linear relations were found between the fluorescence intensity and spectrum area, which showed the same changeable trend of the fluorescence intensity and spectrum area with the concentration change of CDOM. A method was established to quantify the concentration of CDOM in water from different source using the linear relationship between the spectrum area and the concentration. It suits the complicated constituent analysis of CDOM and could really and accurately show the concentration of CDOM in natural water.
2007 Vol. 27 (10): 2083-2087 [Abstract] ( 1849 ) PDF (1354 KB)  ( 736 )
2088 Simultaneous Resolution and Determination of Tyrosine, Tryptophan and Phenylalanine by Alternating Penalty Trilinear Decomposition Algorithm Coupled with 3D Emission-Excitation Matrix Fluorometry
XIAO Jin, REN Feng-lian*, SONG Ge, LIAO Lü, YU Wen-feng, ZENG Tao
A new method using alternating penalty trilinear decomposition algorithm coupled with excitation-emission matrix fluorometry has been developed for simultaneous resolution and determination of tyrosine, phenylalanine and tryptophan. Their correlation coefficients were 0.9987, 0.9995and 0.9993 respectively. The contents of tyrosine, phenylalanine and tryptophan in Hibiscus syriacus L. leaves were also be determined by this method after being extracted by ultrasonic. The coefficients of variation and the recoveries of the three amino acids were 0.84%, 0.36%, 1.59% and 101.0%-92.7%, 106.5%-93.0%, 103.0%-95.0% respectively. All these show that this is a simple, fast and cridible method.
2007 Vol. 27 (10): 2088-2092 [Abstract] ( 1181 ) PDF (1741 KB)  ( 747 )
2093 Synthesis and Fluorescence Properties of the Tb(Ln) Complexes with Trimesic Acid (Ln=Y, Gd)
SONG Hui-hua,YANG Fang,WANG Ji-ye,SHI Shi-kao
In the present paper two series of mixed rare earth complexes Tb(1-x)LnxBTC·nH2O(Ln=Y，Gd, x=0，0.1，0.3，0.5，0.7，0.9) were synthesized by hydrothermal method. The contents of rare earth were measured by using EDTA titration method; the element analyses of C and H were performed by using Vario EL Ⅲ elemental analyzer, and the IR spectra were recorded by FTIR-8900 infrared spectroscopy with KBr pellet. Then the molecular formula of the complexes were determined to be Tb(1-x)LnxBTC·0.5H2O(Ln=Y，Gd). The fluorescence spectrum of all the complexes were recorded by using a Hitachi F-4500 fluorescence spectrophotometer at room temperature. The results indicated that all the complexes emitted characteristic fluorescence of Tb3+, and the fluorescence intensities of the complexes were obviously enhanced with doping rare earth ion of Y3+ or Gd3+. It was showed that Tb3+ was sensitized by doping rare earth ions. This may be because there was intra molecular energy transfer in the complexes. Being doped with the rare earth ion the emission peak positions did not change. Among the four emission peaks, 5D4→7F5(544nm) was the strongest one, and it was found when the proportion is Y3+∶Tb3+=0.5∶0.5 or Gd3+∶Tb3+=0.3∶0.7, the fluorescence intensity of Tb(1-x)YxBTC·0.5H2O or Tb(1-x)GdxBTC·0.5H2O was the greatest, meanwhile the sensitization degree was bigger with doping Gd3+ than doping Y3+ at 544nm.
2007 Vol. 27 (10): 2093-2097 [Abstract] ( 1155 ) PDF (1357 KB)  ( 663 )
2098 Determination of Trace Vitamin B2 by Fluorimetry after Aqueous Two-Phase Extraction Based on Acetone and Ethanol
LONG Wen-qing
Small molecular water-miscible organic solvent, such as ethanol, acetone and acetonitrile, can be used to form aqueous two-phase system for extraction of analytes in the presence of salts. Just based on it, the acetone-salt-H2O and the ethanol-salt-H2O systems were developed for the determination of trace vitamin B2 coupled with fluorimetry after aqueous two-phase extraction. Various factors including the type and amount of salts and organic solvents, extraction time, coexistent substance, and pH were studied. The experimental results show that the extraction efficiencies of vitamin B2 in the acetone-salt-H2O and the ethanol-salt-H2O system were 97.6%-98.4% and 94.2%-95.5%, respectively, in one-step extraction. Under the optimal conditions, these two extraction techniques gave linear dynamic ranges of 1.5×10-7-3.5×10-6 mol·L-1 and 2.0×10-7-1.5×10-6 mol·L-1, with detection limits of 0.031 and 0.041 μg, respectively. Both techniques were applied directly to determination of vitamin B2 in pharmaceutical tablets and injections with satisfactory results. The relative errors were -1.8%-1.1% as compared with China pharmacopoeia and the relative standard deviations were 1.5%-2.2% for vitamin B2 in the above samples. Compared with conventional liquid-liquid extraction or solid-phase extraction, these methods have outstanding advantages such as simple operation, high extraction efficiency, little interference with analytes and low toxicity.
2007 Vol. 27 (10): 2098-2101 [Abstract] ( 1101 ) PDF (1175 KB)  ( 957 )
2102 Preparation and Characterization of Morin-ModifiedSelf-Assembled Multilayer Films of Gold Nanoparticles
HE Fei, SUN Xiang-ying*, LIU Bin
Quartz substrate was modified with self-assembled monolayer of γ-aminopropyl-triethylsilane by aqueous phase silanization, giving an homogenous surface terminated with amino groups. Colloidal gold nanoparticles were further assembled on this functionalized monolayer substrate, forming a gold nanoparticles/APES/quartz nanocomposite structure. Flourescent reagent morin was assembled onto the self-assembled multilayer films of gold nanoparticles via DL-cystenine (Cys) intermediate. The morin-modified self-assembled multilayer films of gold nanoparticles could detect triphenyltin fluorimetrically with high sensitivity, and the detection limit was as low as 1.297×10-8mol·L-1. The effects of various factors such as concentration of solution, pH, and assembling time were investigated. The response mechanism behind caused the enhancement of relative fluorescence intensity was also discussed.
2007 Vol. 27 (10): 2102-2106 [Abstract] ( 1189 ) PDF (1589 KB)  ( 533 )
2107 Study on Classification Model of Seawater Samples with Different Pollution Sources
LIN Yan1, ZHU Er-yi1*, XU Xiao-qin1, LEE Frank S C2, WANG Xiao-ru2
In the present article the principle and advantages of the method to build classification model by partial least squares are briefly introduced. The method was applied to deal with the seawater data obtained from the primary polluted sea area of Jiaozhou bay and Laizhou bay by GC-MS. The classification models have been built for seawater samples from different contaminated areas. The results indicate that PLS is very suitable for dealing with the problems with the data sets that contain many variables and few samples and have serious co-linearity. Accurate classification models can be built by use of PLS to get the classification information of pollution sources from two or many kinds of polluted seawaters data sets from GC-MS. The cross validation relativities of the model comes to over 0.91. This result is approving, which can provide a reliable foundation for distinguishing pollution sources correctly. Moreover, compared with the traditional method, the classification figures constructed by model’s ｉ in the article are more clear and intuitive, and can express the model’s discrimination effect better.
2007 Vol. 27 (10): 2107-2110 [Abstract] ( 1626 ) PDF (1209 KB)  ( 488 )
2111 Application of ICP-MS/ICP-AES to Detection of 22 Trace Elements in Fruits of Elm
RUI Yu-kui1, HAO Yan-ling2, ZHANG Fu-suo1*, JIN Yin-hua2, GUO Jing2
Fruit of elm has been a popular food in Chinese county for many years. With the rapid development of food nutrition and food safety, more and more people begin to pay attention to its content of trace elements and heavy metals. The wild fruit of elm was studied by ICP-MS/ICP-AES to detect the 22 trace elements. The results showed that the fruit of elm contained many trace elements which are necessary to human health: The concentrations of Mg, Ca, Mn, Fe, Cu, Zn, Sr and Rb were 224.57, 269.73, 9.23, 64.93, 1.68, 4.79, 7.68 and 2.21μg·g-1(FW) respectively; while those of Li, B, V, Co, Ni, Se, Br, Mo and Sn were 318.43, 518.83, 265.52, 108.50, 411.21, 34.51, 51.72, 109.90 and 31.51ng·g-1(FW), respectively. Except the wholesome trace elements, contents of heavy metals (As, Cr, Pb and Cd) are also the important standard to identify the quality of food, and the results showed that the concentrations of heavy metals, Pb, Cd, As, Hg and Cr were respectively 557.87, 8.81, 345.55, 0.78 and 347.97ng·g-1(FW) in fruit of elm, which meet the national hygiene standards.
2007 Vol. 27 (10): 2111-2113 [Abstract] ( 1258 ) PDF (893 KB)  ( 493 )
2114 Determination of Metal Elements in Whole Tetraena Mongolia Maxim from West Erdos Region of Inner Mongolia by ICP-AES
LIU Ying1,2, LI Jing-feng2, FENG Jin-zhao1
The sand storm has become a global environmental problem. Since desert woody plants have many special biological characteristics, they play an important role in improving ecological environment and so on. In the present paper, the contents of ordinary and trace metal elements in whole Tetraena Mongolia Maxim, which only exists in West Erdos Region of Inner Mongolia in the world and is protected and endangered national second-class species, were determined by ICP-AES technique and compared with other desert woody plants. The results indicated that the ordinary elements Ca, K, Mg, Na and Al and the trace elements essential to plant vital activities, such as Fe, Mn, Cu and Zn show different content orders in different parts of the plant. For example, the content orders are Ca＞Na＞Mg＞Al＞K＞Fe＞Cu＞Mn＞Zn for both main root and old root. In twig and leaf, however, the order is Ca＞Na＞Mg＞Al＞K＞Fe＞Mn＞Cu＞Zn, while in fibrous root the order is K＞Ca＞Na＞Mg＞Al＞Fe＞Cu＞Mn＞Zn. The element contents of Mn and Zn are lower than the average content of terrestrial plants. The recovery ratio obtained by standard addition method ranged between 94.98% and 120.0%, and its RSD was lower than 3.5% with a good precision. The results provide theoretical directions for protecting and exploiting vegetable resource of the endangered and wilding plant.
2007 Vol. 27 (10): 2114-2117 [Abstract] ( 2409 ) PDF (924 KB)  ( 468 )
2118 Determination of Ca，Mg，Pb，Cd，As and Hg in the Feather of Japanese Crested Ibis
ZHU Xiao-mei,HAN Sen*
Trace elements participate in many important life processes of Japanese crested ibis. A method of simultaneous and direct determination of Ca, Mg, Pb, Cd, As and Hg in the feather of Japanese crested ibis by ICP and HG-AAS is reported. The results show that the method has good precision and accuracy. The recovery is 95%-105%. A long term track of trace elements contained in Japanese crested ibis, particularly the collection and study of the data concerning harmful trace elements, is significant to the improvement in the growth and breeding of the species.
2007 Vol. 27 (10): 2118-2119 [Abstract] ( 547 ) PDF (956 KB)  ( 467 )
2120 Determination of Trace Elements in Scallop
XIN Shi-gang,WANG Ying,ZHAO Na,HAO Lin
The contents of eight trace elements Zn，Co，Fe，Mn，Mg，Ca，Cu and K in scallop were determined by ICP-AES and AAS using nitrifying method of high pressure nitrifying pot.The comparison between the results of two analysis methods was made, which proved no obviously differenct. The recoveries were 93.3%-102.8%, and the relative standard deviations were less than 1.60%. The experiment proved that scallop contains rich and useful trace elements, not only tastesgood and fresh, but also is essential supplemental elements that human body can not synthesize by itself.
2007 Vol. 27 (10): 2120-2122 [Abstract] ( 1167 ) PDF (904 KB)  ( 455 )
2123 Determination of Trace Lead in Chinese Medicinal Materials by GFAAS with PdCl2 as a Matrix Modifier
QIN Fan-xin1, ZHANG Ming-shi1,2, HU Ji-wei2, HUANG Xian-fei3, ZHANG Dan4
A method for the determination of lead in Chinese medicinal materials by GFAAS with PdCl2 as a matrix modifier was established. By comparing PdCl2 with NH4H2PO4 in improving effect on the determination of Pb, the dosage of PdCl2, acidity of medium, interference of coexistent ion, recovery of the method, precision of the method, and the detection limit were checked. The programmed temperature of graphite furnace was optimized. The results show that the improving effect of PdCl2 on Pb determination is better than that of NH4H2PO4. The dosage of PdCl2 is 0.3 μg. The best medium should be 1.0% HCl. The three kinds of acids, 0.4% H2SO4, 1.0% HClO4 and 1.8% HCl, did not weaken the signal of lead. The recovery of the method is 90%-104% and the precision is ＜5.0%. The characteristic mass is 8.5 pg. The detection limit is 0.066 mg·kg-１. It is concluded that the method is simple, sensitive, accurate and credible, and can be used widely.
2007 Vol. 27 (10): 2123-2126 [Abstract] ( 439 ) PDF (1363 KB)  ( 607 )
2127 Study on the Determination of Trace Cu and Mn in Foodstuff Preconcentration by Precipitate Flotation and FAAS
LI Chun-xiang, CHEN Ting-yu, YAN Yong-sheng*
In the present paper, the use of 8-hydroxyquinoline(oxine,HQ) complexs in precipitate flotation to separate and preconcentrate Cu and Mn, using SDBS as collector, followed by AAS spectrophotometric determination is proposed. The optimum conditions of precipitate flotation were studied. The effects of several parameters of flotation processes condition on single metal ions precipitation-flotation and multi-metal ions coprecipitation-flotation of Cu and Mn at pH 9 were investigated. The experimental results show that the flotation rate of Cu is supreme with pH 9. Under the condition of pH 9 and changing the ratio of concentration, when Mn/Cu≥8, the recovery rate of Cu is less than 90%. This method is simple, rapid, accurate, sensitive and precise and avoids using the virulent organic solvent. The linear range of Cu is 0.5-5.0μg·mL-1 with the correlative coefficient of 0.9996,detection limit of this method was found to be 1.59×10-3μg·mL-1, the linear range of Mn is 0.5～5.0μg·mL-1 with the correlative coefficient of 0.9987, and the detection limit of this method was found to be 3.52×10-3μg·mL-1.The method was applied to the determination of Cu and Mn in foodstuff, and the recovery is 87.6%-100.7%, The result was satisfactory.
2007 Vol. 27 (10): 2127-2130 [Abstract] ( 2170 ) PDF (1119 KB)  ( 490 )
2131 Analysis of Eleven Mineral Elements for Eight Benthic Marine Diatoms Using AAS
XING Rong-lian, WANG Chang-hai*, TANG Ning, QIAN Zhen-ming
Eleven mineral-elements, Mg, Fe, K, Ca, Mn, Zn, Cu, Ni, Pb, Cr and Cd, for eight benthic marine diatoms were determined by using flame atomic absorption spectrophotometry (AAS). This method is rapid with high precision and accuracy. The relative standard deviation, correlative coefficient and recovery rate are less then 6.85%, 0.9989-0.9999 and 95%-103%, respectively. The results show that there are high mineral-element levels in the eight benthic diatoms, with Mg>Fe>K>Ca>Mn>Zn among them, while the contents of Ni and Cu are poor, and there are little Pb, Cr and Cd in benthic diatoms. The contents of Mg, K and Mn in Navicula seminulum Grun are maximum elements, with (17.2240±0.030 2)mg·g-1 SD and (1.7885±0.093 9)mg·g-1 SD，(0.225 3±0.001 1)mg·g-1 SD respectively. There were the most contents of Fe(4.231 4±0.030 9)mg·g-1 SD and Zn(0.116 7±0.002 9)mg·g-1 SD, Cu(0.022 7±0.000 7)mg·g-1 SD and Ni(0.014 7±0.000 5)mg·g-1SD in Hantzschia amphioxys (Ehr.) Grun. var. leptocephala Ostrup. The element of maximum content in Nitzschia sp. was Ca (6.3537±0.0412 mg·g-1 SD). The experimental results indicate that the eight benthic diatom species could prove useful feed species for benthic animal species grown in aquaculture such as abalone, sea urchin and sea cucumber.
2007 Vol. 27 (10): 2131-2133 [Abstract] ( 1694 ) PDF (919 KB)  ( 833 )
2134 Study on Performance of Ni3V2O8 Catalyst and Analysis of X-Ray Photoelectron Spectroscopy
XU Ai-ju1,2,ZHAORIGETU Bao2*,JIA Mei-lin2,LIN Qin1
Ni3V2O8 catalyst was prepared by oxalate co-precipitation method with microwave heating in this paper. In order to study the relationship between the catalytic performance and the surface species, the catalyst was characterized by XRD, BET, H2-TPR, XPS, TEM and conductivity measurement. The surface property of Ni3V2O8 was studied by XPS and the catalytic performance of the oxidative dehydrogenation of propane to propylene was also investigated. The results of XRD showed that pure Ni3V2O8 with nice structure was obtained. TEM experiments results demonstrated that the prepared Ni3V2O8 catalyst at 700 ℃ calcination showed uniform particle with the mean particle size of 30 nm. The surface area of the catalyst was 8.623 m2·g-1. The diagram of the relationship between electrical conductivity and oxygen partial pressure of Ni3V2O8 showed dσ/dPO2＞0, implying that Ni3V2O8 catalyst was a p-type semiconductor. H2-TPR results showed that only one unsymmetrical reduction peak appeared at 663.5 ℃ within 300-900 ℃ region over Ni3V2O8 catalyst and no obvious shoulder peak was observed. It could also be found that the ratio of non complete reduction oxygen species was about 33.59%(O- 27.55%, O2-2 6.04%) from the O(1s) XPS result and more V4+ species existed on the Ni3V2O8 catalyst surface. The TPR and XPS results illustrated that the transformation of the lattice oxygen to non-complete reduction oxygen in Ni3V2O8 catalyst might promote the oxidation-reduction reaction between different valence vanadium and promoted the oxygen vacancy formation. This then led to abundant non-complete reduction oxygen O- and V4+ species formation on the surface of Ni3V2O8 catalyst. The active result of oxidative dehydrogenation of propane to propylene showed that the 60.02% propylene selectivity could be reached at 18.60% propane conversion. Compared with the reported results over the coexistent NiO and Ni3V2O8 system from the literature, pure Ni3V2O8 catalyst system in this present paper showed higher propylene selectivity than the coexistent NiO and Ni3V2O8 system under the same propane conversion condition, suggesting that the performance of propane to propene is correlated to the oxidation-reduction of V4+/V5+ couple and non complete reduction oxygen species(O- or O2-2). This result further illustrated that Ni3V2O8 was active phase for oxidative dehydrogenation of propane to propylene. Combining the active and characterization results, it was found that catalytic activity was correlated to the surface non-complete reduction O- and V4+ species, which was beneficial to improving the propylene selectivity.
2007 Vol. 27 (10): 2134-2138 [Abstract] ( 1674 ) PDF (1769 KB)  ( 840 )
2139 Development of Soil-Organic-Matter Fast-Determination Instrument Based on Spectroscopy
TANG Ning,LI Min-zan*,SUN Jian-ying,ZHENG Li-hua,PAN Luan
An instrument used to measure the content of soil organic matter was developed based on spectroscopy. The instrument consists of an optical unit and an electronic unit. The optical unit is used to collect the reflecting light from soil surface and change the filtered light into the electrical signal. The electronic unit includes an amplifying circuit, an A/D circuit, and a display and storage circuit. Three wavebands of filters, 530, 765, and 850 nm, were selected in the performance test in order to determine the optimal one. The soil samples tested include two types, dried soil and air-dry soil. The result shows that there is highest correlation between the reflectance and the content of soil organic matter at the wavelength of 850 nm (r2=0.930) for dried soil. While the coefficient of determination r2 is abouu 0.711 for air-dry soil at the same wavelength. Although the actual precision is lower because of the soil moisture, it is practical in real-time measurement in the field.
2007 Vol. 27 (10): 2139-2142 [Abstract] ( 1860 ) PDF (1612 KB)  ( 535 )

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