基于激光诱导击穿光谱技术定量分析食用明胶中的铬元素

利用激光诱导击穿光谱技术对食用明胶样品中的铬元素进行定量分析.采用Nd:YAG脉冲激光器三倍频输出的355 nm激光诱导击穿食用明胶产生激光等离子体,测量等离子发射光谱.实验数据表明:使用内标法定量分析食用明胶样品中铬元素浓度分别为10—200 ppm(1 ppm=10-6)时,铬元素含量与分析谱线(CrI:245.43 nm)强度之间具有很好的线性关系.分析了光谱探测延迟时间对明胶中铬元素激光诱导击穿光谱的影响,利用信号强度与信噪比获得了优化的光谱探测延迟时间实验参数.

Quantitative analysis of chromium in edible gelatin by using laser-induced breakdown spectroscopy

We quantitatively analyze the concentration of element chromium in edible gelatin sample by the laser-induced breakdown spectroscopy. As the excitation source, Nd:YAG pulsed laser (wavelength 355 nm) is used to generate a laser plasma in edible gelatin. We study the relationship between spectral intensity and delay time, and find that the optimal condition is 1.7 μs. The experimental data show that the relation between the spectral line intensity (CrI: 425.43 nm) and the concentration of chromium is linear when we use the internal standard method to quantitatively analyze the concentration of chromium in a range from 10 ppm to 200 ppm. This study shows that internal standard method of quantitative analysis works well on measuring the chromium concentration in edible gelatin.
Keywords： laser-induced breakdown spectroscopy quantitative analysis calibration curve chromium