激光诱导击穿光谱结合标准加入法定量分析土壤中铅、镉、铬和铜（英文）

发布时间：2018-03-13 11:10

本文选题：激光诱导击穿光谱　切入点：定量分析　出处：《光谱学与光谱分析》2017年10期 　论文类型：期刊论文

【摘要】：利用课题组自主研制的便携式激光诱导击穿光谱测量系统定量分析土壤及固体废弃物中四种重金属元素Pb,Cd,Cr和Cu。实验采用中心波长为1 064nm的Nd∶YAG脉冲激光器作为激发光源,工作频率为3Hz,单脉冲能量为100mJ,脉冲宽度为6ns;以高分辨率、宽光谱段的中阶梯光栅光谱仪和增强型电荷耦合器件为谱线分离与探测器件,探测范围为200~500nm,分辨率为0.08~0.12nm。为了提高光谱强度及检测灵敏度,通过半球空间约束装置对等离子进行约束,并采用多芯光纤实现多通道不同角度光谱信号收集,接收角度为45°。实验时激光重复频率为2Hz,延时为1.5μs,门宽为1.05ms。文章创新性地将曲线拟合代替直线拟合用于标准加入法定量分析基质未知样品中重金属元素,有效提高了测量结果的准确性,尤其是低浓度的土壤样品,直线拟合无法定量分析重金属含量,相比而言,曲线拟合相关系数更高,测量结果更接近国标方法,可以满足一级土壤污染的检测。七个土壤及固体废弃物样品检测的相对误差如下,直线拟合相对误差分别为:Pb 1.26%~79.38%,Cr-22.44%~82.06%,Cu 15.09%~190.50%,Cd 32.76%~167.96%,曲线拟合相对误差为分别Pb-4.19%~11.92%,Cr-38.31%~9.26%,Cu-7.24%~26.86%,Cd-10.52%~12.94%,相对误差平均值为10.47%。
[Abstract]:A portable laser-induced breakdown spectrometric system was developed for quantitative analysis of four heavy metal elements in soil and solid waste. The Nd:YAG pulse laser with a central wavelength of 1064nm was used as the excitation source. The working frequency is 3Hz, the single pulse energy is 100mJ, the pulse width is 6ns, the high resolution, wide spectrum band middle step grating spectrometer and the enhanced charge coupled device are used as the line separation and detector. In order to improve the spectral intensity and detection sensitivity, the plasma is constrained by the hemispherical space confinement device, and the multi-channel and different angle spectral signal is collected by using multi-core fiber, the detection range is 200 ~ 500 nm and the resolution is 0.08 ~ 0.12 nm. The receiving angle is 45 掳, the laser repetition rate is 2 Hz, the delay is 1.5 渭 s, and the gate width is 1.05 Ms. This paper innovatively uses curve fitting instead of straight line fitting for quantitative analysis of heavy metal elements in unknown matrix samples by standard addition method. The accuracy of the measurement results is improved effectively, especially in the low concentration soil samples, the linear fitting can not quantitatively analyze the heavy metal content, in contrast, the curve fitting correlation coefficient is higher, and the measured results are closer to the national standard method. The relative errors of the seven soil samples and solid waste samples were as follows. The relative errors of the straight line fitting were 79.38 Cr-22.44440.06K, Cu 15.090.50cu 32.767.96, and the relative errors of curve fitting were Pb-4.1911.92Cr-38.31U 9.269.26Cu-7.248626.8626cd-10.52n 12.940.The average relative error was 10.4747.
【作者单位】：中国科学院安徽光学精密机械研究所中国科学院环境光学与技术重点实验室;安徽省环境光学监测技术重点实验室;中国科学技术大学;
【基金】：the support of the project of the Science and Technology program of Anhui province(1501041119) the science and technology major special program of Anhui province(15CZZ04125) the National Key Research and Development Plan(2016YFD0800902-3) National“863”program(2014AA06A513)
【分类号】：O657.31;X833

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