[Simultaneous Analysis of 18 Glucocorticoids in Surface Water]

A method of ultra-performance liquid chomatography tandam mass spectrometry(UPLC-MS/MS) combined with solid-phase extraction (SPE) has been developed for simultaneous analysis of 18 glucocorticoids in surface water. The analytes were first enriched and purified through a HLB cartridge, and eluted with acetonitrile/ethyl acetate (1:1, V/V), then detected by UPLC-MS/MS. The detection used gradient elution process with methanol and 0. 1% formic acid/water (V/V) as the mobile phase to achieve baseline separations of these 18 analytes. The linear range was 1. 0-1 000 µg.L-1. The method detection limits (MDLs) were 0. 10-1. 0 ng.L-1 except for cortisone acetate and cortisol acetate(10 ng.L-1) with overall mean recoveries of 65% - 108% in surface water. Application of this method for 5 surface waters from Beijing area showed that 8 glucocorticoids were detected with the concentration range of 0. 20-476 ng.L-1. Triamcinolone, triamcinolone acetonide, cortisol acetate and clobetasol propionate were detected for the first time in surface water samples, suggesting that this method is efficient for real sample analysis.