Determination of some drugs and their derivatives by analytical and chemometric methods

In quantitative determinations, in case of overlapping spectra or chromatogram peaks, the amount of components in the mixture can be estimated by multivariate calibration techniques. Within the scope of the thesis study, standard solutions containing amphetamine, methamphetamine, MDMA, cocaine and heroin at five different concentration levels were prepared according to PCR and PLS methods, which are multivariate calibration techniques. After the analysis of 25 solutions in the prepared calibration and validation sets with GC-FID, the chromatogram data were taken. The number of latent variable was calculated for the quantitative determination of the substances in the mixture in PLS and PCR algorithms. After the chromatographic data obtained were prepared for analysis with preprocessing techniques, the amounts of drugs in each solution were found by PLS and PCR analysis. The root mean square error of values were calculated for each drug. Considering the % error values for the estimated concentrations, the PLS error values for the calibration set were found to be lower than the PCR error values. Then, the amount of narcotic substances in real samples were analyzed by chemometric method. The results found were consistent with the chromatographic results. While analyzing samples containing more than one active substance, accurate, precise, reliable and fast results should be obtained from chemometric methods while solving analytical problems.