Qualitative and quantitative evaluation of blood cholesterol using laser plasma spectroscopy and calibration-based linear discriminant analysis

摘要

In this paper, the cholesterol concentration of human blood serum is qualitatively and quantitatively scrutinized via laser-induced breakdown spectroscopy (LIBS) and discriminant function analysis (DFA). To achieve this goal, four normal standard samples with different concentrations of cholesterol and one pathological sample as a target, all from human blood serum, are prepared. Initially, the range of cholesterol concentration of the target compared to that of standard samples is determined using three bar charts related to the spectral intensities of cholesterol components. Then, in contrast to the common cases, the DFA is exploited to measure the cholesterol concentration of the target. First of all, three discriminant functions (DFs), their contributions in the discrimination, and groups' centroid for all DFs are determined. Thereafter, for each DF, the cholesterol concentration of the samples is plotted against the centroid of the groups as a linear calibration diagram (LCD). Eventually, the cholesterol concentration of the target and its standard error of the mean (SEM) are calculated using the contributions obtained from LCDs by considering and exerting the discrimination percentages of DFs. Comparing the results with the values certified by the manufacturer about the target indicates strong performance of this approach in quantitative analyses.