CAPILLARY GAS-CHROMATOGRAPHY OF ACIDIC NONSTEROIDAL ANTIINFLAMMATORY DRUGS AS TERT-BUTYLDIMETHYLSILYL DERIVATIVES

The quantitative conversion of 26 acidic non-steroidal anti-inflammatory drugs (NSAIDs) simultaneously to their corresponding tert.-butyldimethylsilyl (TBDMS) derivatives in a single step was examined. The NSAIDs dissolved in triethylamine were silylated with N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide in isooctane at room temperature for 30 min and subsequently analysed by capillary gas chromatography and gas chromatography-mass spectrometry. The TBDMS derivatives were eluted as untailed sharp peaks and the characteristic [M-57]+ ions in the mass spectra permitted their rapid confirmation. The temperature-programmed retention index (I) sets measured on a DB-5 and DB-17 dual-capillary column system were characteristic of each NSAID to be used for the rapid identification by computer I matching. The derivatization yields of the NSAIDs studied were linear in the range 10-120 mug with high overall precisions. The method provided simultaneous screening and accurate confirmation of each drug when applied to serum samples spiked with NSAIDs.