共轴双脉冲激光诱导击穿光谱结合双谱线内标法定量分析植物油中的铬

发布时间：2018-03-24 15:17

本文选题：双脉冲激光诱导击穿光谱　切入点：内定标法　出处：《物理学报》2017年05期

【摘要】：采用共轴双脉冲激光诱导击穿光谱(DP-LIBS)技术对3种植物油中的重金属铬(Cr)含量进行定量分析.对实验配制的24个样品,来用桐木木片对其中的Cr进行富集,烘干后进行LIBS试验.选取Cr I 425.39 ran为定量分析谱线,CN分子谱线(421.49 nm)、Ca原子谱线(422.64 nm)以及它们谱线强度之和为内标线,分别建立了Cr的基本定标法、单谱线内标法和双谱线内标法的定标曲线,并用验证样品对它们进行检验.研究结果表明,3种植物油的基本定标曲线的拟合度R~2在0.97以上,低浓度验证样品预测的相对误差较大;采用单谱线内定标法时,定标曲线拟合度R~2在0.98以上,验证样品预测的相对误差较基本定标法有所降低;来用双谱线内标时,大豆油、花生油和玉米油的内定标曲线拟合度R~2分别为0.995,0.992和0.996,2个验证样品预测的相对误差分别为12.81%,1.73%,9.19%,6.05%和6.23%,6.69%.由此可见,采用双谱线内标法能有效减小定量分析误差,提高LIBS对植物油中Cr元素的预测能力.
[Abstract]:The content of Cr in three kinds of vegetable oils was quantitatively analyzed by coaxial double-pulse laser induced breakdown spectroscopy (DP-LIBS). 24 samples were prepared for enrichment of Cr with tung wood chips. After drying, the LIBS test was carried out. The Cr I 425.39 ran was selected as the quantitative analysis line of CN (421.49 nm) and the sum of the intensity of these lines as the internal standard line, and the basic calibration method of Cr was established. The calibration curves of single line internal standard method and double spectral line internal standard method were tested by verifying samples. The results showed that the fitting degree of the basic calibration curves of three kinds of vegetable oils was more than 0.97. The relative error of low concentration sample prediction is large, the fitting degree of calibration curve R _ (2) is above 0.98, the relative error of sample prediction is lower than that of basic calibration method, when using double spectral line internal standard, soybean oil, the relative error of sample prediction is lower than that of basic calibration method. The fitting degree of the internal calibration curve of peanut oil and corn oil is 0.992 and 0.996, respectively. The relative errors of the two verification samples are 12.81and 1.739.199.05% and 6.236.69g respectively. It can be seen that the error of quantitative analysis can be effectively reduced by using the method of internal standard of double spectral line. The ability of LIBS to predict Cr in vegetable oil was improved.
【作者单位】：江西农业大学生物光电技术及应用重点实验室;
【基金】：国家自然科学基金(批准号:31401278) 江西省自然科学基金(批准号:20132BAB214010,20151BAB204025)资助的课题~~
【分类号】：TN249

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