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 mu s. 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.