No abstract

No abstract

Ketoprofen (KP) is a nonsteroidal anti-inflammatory drug, which during UV irradiation rapidly transforms into benzophenone derivatives. Such transformation products may occur after topical application of KP, which is then exposed to sunlight resulting in a photo-allergic reaction. These reactions are mediated by the benzophenone moiety independently of the amount of allergen. The same reactions will also occur during wastewater or drinking water treatment albeit their effect in the aqueous environment is yet to be ascertained. In addition, only a few such transformation products have been recognised. To enable the detection and structural elucidation of the widest range of KP transformation products, this study applies complementary chromatographic and mass spectrometric techniques including gas chromatography coupled to single quadrupole or ion trap mass spectrometry and liquid chromatography hyphenated with quadrupole-time-of-flight mass spectrometry. Based on structural information gained in tandem and multiple MS experiments, and on highly accurate molecular mass measurements, chemical structures of 22 transformation products are proposed and used to construct an overall breakdown pathway. Among the identified transformation products all but two compounds retained the benzophenone moiety--a result, which raises important issues concerning the possible toxic synergistic effects of KP and its transformation products. These findings trigger further research into water treatment technologies that would limit their entrance into environmental or drinking waters.

No abstract

The use of a derivatization procedure for the measurement of aldoses by forming alditol acetates by strong acid hydrolysis is described. Quantitative data based on standard mixtures of neutral sugars were obtained by capillary gas chromatography and gas chromatography-mass spectrometry using phenyl-B-D-glucopyranoside as an internal standard. Tandem mass spectrometry was used for the structural elucidation of complex saccharide mixtures. In order to differentiate between alditol acetates, i.e., hexitols, pentitols and deoxyhexitols, the collision-activated reactions m/z 361+259,303+201 and 2174115 were monitored by the Q sector of a VG-AutospecQ mass spectrometer. The method was applied to the study of the composition of polysaccharides in particulate organic matter and macroaggregates in the northern Adriatic Sea.