Selectivity of Identification of Similar Compounds by IR Spectrometry

This paper focuses on the investigating three methods of positive identification or discrimination of a substance when it is compared to a set of similar ones, applying the quantitative criteria. Correlation coefficients were compared between the transmission, absorption, and the first derivatives of absorption spectra. The latter was the method that proved to have the most discriminating power. The investigation involved exploring a group of structurally related compounds, namely a group of fourteen benzodiazepines. Limiting values were proposed for correlation coefficients so as to allow qualification of a substance as the same as the reference one.