为克服自吸收效应对炉渣样品定量分析结果的影响, 基于快速模拟退火算法的优化过程, 结合等离子体发射光谱的基本理论, 发展了一种基于多种粒子发射谱线的自吸收校正算法, 给出了该算法的流程图。 利用前述自吸收校正算法分别对精炼渣和高炉渣样品的激光诱导等离子体发射光谱强度进行校正, 并结合无标分析法, 对比分析了自吸收校正算法对样品成分定量分析结果的影响。 对比自吸收校正前后的Boltzmann图可以看出, 经自吸收校正后, 等离子体中各粒子的温度均稳定在11600K左右, 结果明显趋于一致。 利用自吸收校正后同种粒子的等离子体光谱构建的Boltzmann图中, 除一组数据外, 其他数据在Boltzmann图中的截距基本一致。 利用经自吸收校正后的谱线, 对两种炉渣样品成分进行定量分析的结果表明: 对于精炼渣, MgO的定量分析结果精度不高, 若不分析MgO的含量, 则CaO, Al2O3和SiO2等成分定量分析结果的相对误差会明显降低; 对于MgO含量为8.49%的高炉渣样品, Al2O3定量分析结果的精度最高, 相对误差为2.38%, MgO最低, 相对误差为28.27%, 但基本可以反映出该成分在样品中的含量。

The laser-induced breakdown spectroscopy is used to analyze the lead content in soils. The analyzed spectral line profile is fitted by Lorentzian function for determining the background and the full-width at half-maximum (FWHM) intensity of spectral line. A self-absorption correction model based on the information of spectral broadening is introduced to calculate the true value of spectral line intensity, which refers to the elemental concentration. The results show that the background intensity obtained by spectral profile fitting is very effective and important due to removing the interference of spectral broadening, and a better precision of calibration analysis is acquired by correcting the self-absorption effect.