Abstract:Based on laser induced breakdown spectroscopy data analysis, a quantitative determination method of elements was introduced. This method takes the advantage of Fourier analysis to study different part of the spectrum-white noise, thermal radiation and emission spectral lines. Through band-pass filter, emission spectral lines and most noise were separated, only a little white noise was missed. By calculated similarity between detected line and its corresponding unit characteristic line, convolution intensity was introduced to measure the detected line intensity. With Cu 324.75 nm as the analysis line and Ti 337.28 nm as the base line, the way of separating spectrum mentioned before was carried out to detect trace Cu pollution in soil. Results contained two bright spots. First, The correlation coefficient between Cu concentration and the spectral intensity was up to 0.997 9. Last but not the least, the detectability of Cu in soil was 44 mg·kg-1, which is below the trace element thresholds for Class 2 soil used in the environmental quality standard for soil in China. At the same time, the relative error is always below 10%. Therefore the feasibility of this method for portable and instant detection of heavy metals in polluted soil was verified.
[1] Capitelli F, Colao F, Provenzano M R, et al. Geoderma, 2002, 106(1): 45. [2] TANG Xiao-shuan, LI Chun-yan, ZHU Guang-lai, et al(唐晓闩,李春燕,朱光来,等). Chinese J. Lasers (中国激光), 2004, 31(6): 687. [3] Sirven J B, Bousquet B, Canioni L, et al. Analytical and Bioanalytical Chemistry, 2006, 385(2): 256. [4] Samek O, Beddows D C S, Kaiser J, et al. Opt. Engng., 2000, 39(8): 2248. [5] Lo K M, Cheung N H. Appl. Spectroscopy, 2002, 56(6): 682. [6] David W Hahn, Prasoon K Diwakar, Philip B Jackson. CLEO 2008, CMQ5, 2008. [7] Corsi M, Cristoforetti G, Palleschi V, et al. Eur. Phys. J. D, 2001, 13:373. [8] YU Le, ZHAO Hua-feng, MA Xiao-hong, et al(于 乐,赵华凤,马晓红,等). Laser Journal(激光杂志), 2008, 29(5): 64. [9] Sarzyński A, Skrzeczanowski W, Marczak J, et al. Proc. of SPIE, 2007, 6618:66180V. [10] Aragón C, Aguilera J A. Spectrochimica Acta Part B, 2008, 63: 893. [11] Mario Capitell, Francesco Capitelli, Alexander Eletskii. Spectrochimica Acta Part B, 2000, 55(2): 559. [12] Kim D E, Yoo K J, Park H K, et al. Appl. Spectroscopy, 1997, 51(1): 22. [13] XIN Ren-xuan(辛仁轩). Plasma Emission Spectrum Analyze(等离子体发射光谱分析). Beijing: Chemical Industry Press(北京:化学工业出版社), 2005. 117. [14] Huang Jer-Shing,Ke Ching-Bin, Huang Li-Shing, et al. Spectrochimica Acta Part B, 2002, 57(1): 35.