A distinct approach to laser plasma spectroscopy through internal reference standard method with peak intensity-based self-absorption correction

The main goal of this paper is to develop a distinct approach to laser-induced breakdown spectroscopy (LIBS) via internal reference standard (IRS) method with peak intensity-based self-absorption correction. On the other hand, since calcium amount of the body is determinant in the extent of osteoporosis, today, qualitative and quantitative analyses of plants rich in calcium is of particular importance. Hence, to evaluate the approach, calcium concentration of the leaf of five plants, fennel, bay leaf, dandelion, spinach, and parsley is determined using a special formulation which can be applied for four different combinations of neutral and once-ionized states of calcium as the analyte and copper as the IRS. The essential parameters of plasma including temperature and electron density, and eventually the calcium concentration are calculated for each leaf before and after correcting the self-absorption effect. Comparison of the results obtained from the method LIBS-IRS before correcting the self-absorption with those measured by inductively coupled plasma optical emission spectrometry indicates that, in determining the concentrations, there exist serious relative errors to the extent more than 189%; and this is while after correcting the self-absorption, the relative errors are reduced to the extent less than 2.8%. Accordingly, one can conclude that self-absorption correction using the peak intensity-based model surprisingly enhances accuracy of the method.