27:T487,

Ganciclovir (GCV) is an antiviral drug used to treat cytomegalovirus infections associated with AIDS. The study of the GCV drug substance under photo-oxidation stress conditions identified five impurities. This study aims to interpret the chemical structures of the photo-oxidation products using quadrupole time-of-flight (Q-TOF) mass spectrometry. An optimized chromatographic technique employing reverse-phase high-performance liquid chromatography with photodiode array detection was used to identify the degradation products of GCV. This technique utilized an Endurus Phenyl-hexyl HP column with an eluent mixture of acetonitrile, methanol, and 1 M ammonium formate (pH 3.2). GCV's photo-oxidation products were effectively separated, achieving a resolution higher than 2.0. The Q-TOF mass spectrometry analysis characterized the five degradation products, which included 8-Oxo GCV, secondary degradation of 8-Oxo GCV, guanine, and one dehydrogenated compound. These new impurities require special attention because the drug's potency and impurity levels significantly influence the quality, safety, and effectiveness of pharmaceutical products.

28:T549,

A series of N,N-dialkylacetimidamides (amidines) (1–10) are designated as non-scheduled reportable chemicals under the Chemical Weapons Convention by the Organisation for the Prohibition of Chemical Weapons (OPCW). The amidines are relevant precursors and degradation products of highly toxic Novichok nerve agents. These amidines and their methyl derivatives (11–20) were systematically investigated under electron ionization (EI) mass spectral conditions. These compounds showed molecular ions with considerable abundance in their mass spectra. Each amidine was identified and characterized based on its characteristic fragmentation pattern. Among these, the possible six sets (3–5; 6 & 7; 8–10 and 13–15; 16 & 17; 18–20) of structural isomers were distinguished unambiguously using their fragmentation pattern and ion intensities. Additionally, retention indices were determined for all the analytes by following the OPCW work instructions. The combined EI mass spectral data and retention indices provide reliable identification of these amidines at trace levels in complex environmental matrices.