National Engineering Research Center for Information Technology in Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
Abstract:The real-time measurement of potassium in farmland soil has great importance. A method to determine the potassium content in farmland soil based on laser-induced breakdown spectroscopy (LIBS) was studied using a LIBS equipment consisting of a 1 064 nm laser generator and a high resolution spectrometer. The farmland soil samples with potassium content in the range of 8.74~34.56 g·kg-1 were analyzed. The 766.49 nm was chosen as the analysis line, by comparing the potassium atom characteristic lines of 404.40, 404.72, 766.49 and 769.90 nm. The errors of characteristic line strength caused by the laser stability and random noise was analyzed. The silicon, which is nearly constant in farmland soil, was chosen as the standard element, and a calibration model between the ratio of potassium to silicon (K/Si) and the potassium content was established. The linear fitting degree of the calibration curve was 0.935, and the relative standard deviation of the calibration model for prediction set samples was 9.26%.
[1] LIAO Yu-lin, ZHENG Sheng-xian, HUANG Jian-yu, et al(廖育林,郑圣先,黄建余,等). Chinese Agricultural Science Bulletin(中国农学通报), 2008, 24: 255. [2] GAO Di, ZHANG Qing, CUI Yun-cheng, et al(高 頔,张 清,崔运成,等). Chinese Agricultural Science Bulletin(中国农学通报), 2012, 28(3): 152. [3] David A Cremers, Leon J Radziemski. Handbook of Laser-Induced Breakdown Spectroscopy, Wiley, England, 2006. 23. [4] Beldjilali S, Borivent D, Mercadier L, et al. Spectrochimica Acta Part B, 2010, 65: 727. [5] Gondal M A, Seddigi Z S, Nasr M M, et al. Journal of Hazardous Materials, 2010, 175: 726. [6] Michael H Ebinger, M Lee Norfleet, David D Breshears, et al. Soil Science Society of America Journal, 2003, 67: 1616. [7] Madhavi Z Martin, Nicole Labbé, Nicolas André, et al. Soil Science Society of America Journal, 2010, 74: 87. [8] Hussain T, Gondal M A, Yamani Z H, et al. Environment Monitoring Assess, 2007, 124: 131. [9] David A Cremers, Michael H Ebinger, David D Breshears, et al. J. Environ. Qual., 2001, 30: 2202. [10] Shiwani Pandhija, Rai A K. Environment Monitoring Assess, 2009, 148: 437. [11] Bousquet B, Sirven J B, Canioni L. Spectrochimica Acta Part B, 2007, 62: 1582. [12] Barbini R, Colao F, Fantoni R, et al. Proceedings of EARSeL-SIG-Workshop LIDAR, Dresden/FRG, 2000, 6(16-17): 122. [13] Sirven J B, Bousquet B, Canioni L, et al. Anal. Bioanal. Chem., 2006, 385: 256. [14] Ronny D Harris, David A Cremers, Michael H Ebinger, et al. Applied Spectroscopy, 2004, 58: 770. [15] Madhavi Z Martin, Stan D Wullschleger, Charles T Garten Jr., et al. Applied Optics, 2003, 42: 2072. [16] CHEN Kai, LU Ji-dong(陈 凯,陆继东). High Power Laser and Particle Beams(强激光与粒子束),2011, 23(2): 293. [17] LU Wei-ye, LU Ji-dong, YAO Shun-chun, et al(卢伟业,陆继东,姚顺春,等). Chinese Journal of Laser(中国激光),2011, 38(10): 169.