Solid-phase extraction coupled simple on-line derivatization gas chromatography-tandem mass spectrometry for the determination of benzophenone-type UV filters in aqueous samples

The rapid determination of three benzophenone-type UV filters: 2-hydroxy-4-methoxy-benzophenone (BP-3), 2,4-dihydroxybenzophenone (BP-1) and 2,2'-dihydroxy-4-methoxy-benzophenone (BP-8), in aqueous samples is described. The method involved the extraction of an aqueous sample using an Oasis HLB solid-phase extraction (SPE) cartridge, followed by on-line derivatization gas chromatography - tandem mass spectrometry (GC-MS/MS) with a trimethylsilylating (TMS) reagent. This eco-friendly, injection-port derivatization method, is sensitive, rapid, and provides reproducible results for these hydroxylated benzophenones in aqueous samples. The limits of quantitation (LOQs) were determined to be 1.0 to 2.5 ng/L for samples in 100 mL of water. The precision for these analytes, as indicated by relative standard deviations (RSDs), proved to be less than 11% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction yield, was between 80 and 106%. The method was then applied to some environmental water samples, river water and samples of effluents from a wastewater treatment plant (WWTP), having the potential to contain BP-3 and BP-1.