在对激光诱导击穿光谱数据分析的基础上提出了一种可以用于元素定量分析的方法.该方法利用傅罩叶分析的方法研究了光谱数据中的不同部分(白噪声、热辐射噪声和原子发射光谱),通过带通滤波实现发射光谱与大部分噪声的分离,得到仅含少量白噪声的发射光谱;通过计算待量化元素谱线与其对应单位强度特征谱线的相似度引入卷积强度来衡量待测谱线的强度.选取Cu 324.75nm作为分析线,Ti 337.28nm谱线作为参考线,采用上述方法对含微量Cu元素土壤样品进行了测量.实验结果显示:Cu元素含量和其卷积强度的线性系数达到0.9979,计算得到土壤中Cu元素的检测限为44 mg·kg-1,达到国家土壤环境质量标准规定的二级土壤中Cu含量要求,测量相对误差在10%以内,表明该方法能够满足土壤微量重金属检测简便、快速的要求.%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 mR . 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.
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