Determination of Mixed Organic Compound by Fourier Transform Infrared Spectroscopy Using Multivariate Analysis.

Abstract

Multivariate analysis was applied to the determination of a mixed organic compound by Fourier transform infrared spectroscopy (FT-IR) and each component was measured accurately without pretreatment such as separation procedure or addition of internal standard substance. For example, the mixture of tetracaine hydrochloride and glucose or methamphetamine hydrochloride and ephedrine hydrochloride (known blend composition) was measured by FT-IR. The obtained spectra were expressed by relative values to provide a data base. A mixture with unknown blend composition ratio (unknown sample) was dealt with in a similar manner. The obtained data were used for the multivariate analysis such as quantification IV, cluster analysis, cluster analysis from deviation and principal component analysis. The rough blend composition ratio of unknown sample was estimated and the data base for calibration curve was selected. Furthermore, the blend composition ratio was determined more accurately by the principal component scores.