On-line Vapor-Phase Generation Followed by Fourier-Transform Infrared Spectrometry for the Quantitative Analysis of Water-Soluble Penicillin G in Pharmaceutical Formulations

摘要

The combination of vapor-phase generation (VPG) and Fourier-transform infrared (FTIR) spectrometry was performed as an alternative analytical technique for the determination of water-soluble penicillin G (PENG). Samples were transferred into a heated reactor, and a potassium iodate solution was injected into the reactor. Carbon monoxide (CO) generated under these conditions was carried via a N2 gas carrier stream inside the IR gas cell, and the corresponding FTIR spectra were continuously recorded as a function of time. Analytical measurements were made using the maximum absorbance of the CO band at 2170 ± 4 cm−1. Various factors influencing the analytical signals were evaluated and selected. The figures of merit of the proposed method involve a linear calibration curve over the range of 3 to 320 mg L−1, a limit of detection of 0.5 mg L−1 and a precision of 2.6%. The method was successfully applied to PENG determination in pharmaceutical preparations.