Abstract:Spectroscopic data pre-processing is important to spectra scaling and quantitative analysis, and correction of baseline drift caused by variation of measuring condition is critical in NIR spectroscopy analysis in-situ. In the present paper, the NIR absorption spectra of propane and isobutane with different concentration were detected by BRUKER EQUINOX55 spectrometer. The “Derivative-smooth” method and the baseline correction method which is accessory of the instrument were theoretically analyzed, and the data processed by the two kinds of method were compared. The results show that the method that is accessory of the instrument can correct steady-state and linear drift, and can gain high SNR, high accuracy; “Derivative- smooth” method has better applicability, can correct non-steady-state and nonlinear drift better, and is a good kinds of pre-processing method in analysis in situ.
[1] Rathbun R E. Critical Reviews in Environmental Science and Technology,2000, 30(2): 129. [2] Seko T, Onda N. Analytical Sciences, S, 1997, 13: 437. [3] Hussam A, Alauddin M, Khan A H. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering,2002, 37(7): 1223. [4] YAN Yan-lu, ZHAO Long-lian, HAN Dong-hai, et al(严衍禄,赵龙莲,韩东海,等). Analysis Basis and Technique for Near-Infrared Spectra(近红外光谱分析基础与应用). Beijing:Chinese Light Industry Press(北京: 中国轻工业出版社),2005. 100. [5] Maleki M R, Mouazen A M, Ramon H. Biosystems Engineering,2007, 96(3): 427. [6] Acharya T, Chakrabarti C A. Journal of VLSI Signal Processing Systems for Signal Image and Video Technology,2006, 42(3): 321. [7] TIAN Gao-you, YUAN Hong-fu, CHU Xiao-li, et al(田高友,袁洪福,褚小立,等). Spectroscopy and Spectral Analysis(光谱学与光谱分析),2005,25(4): 516. [8] YING Hai, YANG Peng-yuan, WANG Xiao-ru, et al(应 海,杨原,王小如,等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 1998, 18(6): 687.