Determination of the Concentration of Nitrazepam and Diazepam with Many Fragment Ions by Multivariate Analysis

Abstract

After nitrazepam and diazepam were measured by gas chromatograph mass spectrometer (GC/MS), their quantitative analyses were carried out with the ion intensities of many fragment ions by multivariate analysis. Dotriacontane (n-C821-166) was used as an internal standard. Their fragment ions of nitrazepam, diazepam and dotriacontane used for the quantitative calculation were subtracted with quantification IV. Cluster analysis, cluster analysis from deviation and principal component analysis were performed with the ion intensities of the subtracted fragment ions, and it was made certain which one of unknown samples among all was the closest to a given known sample. Furthermore, the concentrations of unknown samples were exactly determined with the principal component scores and eigen values obtained from principal component analysis. The calculated concentrations of nitrazepam and diazepam agreed well with the theoretical concentrations, and the quantitative analysis which has high preciseness was made possible.