Photostability testing using online reactor HPLC hyphenation and mass spectrometric compound identification illustrated by ketoprofen as model compound

Reconsidering mass spectrometric fragmentation in electron ionization mass spectrometry – new insights from recent instrumentation and isotopic labelling exemplified by ketoprofen and related compounds

“…Generation of BP06-d 3 and BP08-d 3 was achieved by using BP01-d 3 as starting material via a photodegradation reaction. 19 Compared with the original compounds, mass shifts of 3 m/z units were detectable in the respective mass spectra. The second deuteration method consisted of introducing d 9 -TMS groups into compounds BP01 to BP06 via derivatization with d 9 -TMCS.…”

“…The focus of interest was their detection in the environment as a water pollutant, for example, in wastewater, 14 poultry manure, 15 surface water and sediments, 16 and ground and drinking water, 17 and the elucidation of its photo-transformation processes. [18][19][20] Thus, ketoprofen, together with seven of its related benzophenone impurities, including those listed in the European Pharmacopeia, is a perfect model compound where a large amount of mass spectrometric information is available. Correlations between the benzophenone backbone structure and fragmentation behavior may help to clarify ambiguities and correctly interpret mass spectra.…”

“…The product ion mass spectrum of the precursor [C 18 H19 O 3 Si] + at m/z 311 (CF1,Figure 8) of BP01-TMS shows the CF2 ion. Confirmation is derived from the product ion spectra of CF1 of the isotopologues(m/z 314, BP01-d 3 -TMS and m/z 317, BP01-TMS-d 9 , respectively).…”

Visualization of the photodegradation of a therapeutic drug by chemometric-assisted fluorescence spectroscopy

“…[1][2][3][4] Light is one of the most serious causes of the degradation of heterocycles in the active pharmacophore of a drug. [5][6][7][8][9][10][11] This physical trigger not only reduces efficacy but also produces toxic effects brought about by the generation of photodegradation products. 12 Thus, the assessment of drug photostability is essential to ensure both proper use and patient safety.…”