Fipronil is degraded photolytically and photocatalytically (β-Ga2O3 and TiO2) in aqueous media under UVC illumination and under reductive and oxidative conditions.

Surface ionization organic mass spectrometry (SIOMS) has been performed on some clinically important drugs (imipramine, desipramine, clomipramine, lidocaine) by using quadrupole mass spectroscopy in which the thermal ion source has a rhenium oxide emitter. The mass spectra were presented, interpreted in a purely empirical way, by means of evidence from previous investigations, and then compared to conventional EI techniques. Sensitivity and selectivity have also been studied, demonstrating that (a) these drug compounds are efficiently surface-ionized, (b) experimental results rationalize the high sensitivity of the surface ionization detector (SID) of gas chromatography (GC) for the examined drugs, and (c) the GC/SIOMS coupling can be used for sensitive and selective detection of the drugs in the serum. An approach to detection of these drugs in serum by GC/SIOMS and GC with SID is described. The characteristics of both methods provide a reliable, sensitive, and selective method, which is needed for low concentration level measurements in complex mixtures.

Persistent fluorinated substances, such as the fluorine-bearing pharmaceutical drugs Fluoxetine (FLX; Prozac) and Fluvoxamine maleate (FOM) together with several other substrates (fluorobenzoic acid and fluoroaliphatic model compounds), were photochemically defluorinated and degraded under UVC illumination in relatively good yields in the presence of a wide band gap metal oxide (β-Ga2O3) in heterogeneous aqueous media. The formation of fluoride ions increased with increasing illumination time under an inert nitrogen atmosphere, the transformation of the aromatic moiety was slower under these conditions, but nonetheless it did occur. The optimal amount of β-Ga2O3 loading for defluorination was 50 mg in aqueous media (0.10 mM, 100 mL); the optimal pH to defluorinate FLX was pH 6. Platinization (1 wt%) of the gallium oxide particles enhanced defluorination under an inert nitrogen atmosphere, but was decreased under an oxygen atmosphere; however, in the latter case the degradation of the substrates was facilitated as witnessed by loss of the aromatic moiety. The Ames test on the intermediate products from the photodegradation of FLX and 4-(trifluoromethyl)benzoic acid after long illumination times revealed that none were mutagenic.

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