Simultaneous Determination of Androgens and Progestogen in Surface Water and Sediment by Gas Chromatography-Mass Spectrometry

A method based on gas chromatography-mass spectrometry (GC-MS) was developed for the simultaneous determination of androgens and progestogen, such as dihydrotestosterone (DIHYDRO), testosterone (TEST), androstenedione (AND) and progesterone (PROG) in surface water and sediment. The method was developed by using microwave-assisted extraction (MAE), solid phase extraction (SPE) and derivatization procedure. The MAE, SPE and derivatization procedure were investigated and optimized. The optimized conditions were as follows: sediment samples were extracted with ethyl acetate by microwave extraction system at 120 °C for 15 min; the water samples pH value were set at 4 and Oasis HLB cartridges were used with ethyl acetate as eluting solvent, trimethyliodosilane as catalytic agent and N-methyl-N-(trimethylsilyl)-trifluoroacetamide as the reagent of derivatization. The hydroxyl and ketone groups of target compounds were simultaneous derivatizated at 40 °C for 20 min. The method had good repeatability and reproducibility with relative standard deviations < 9% for all target compounds in both matrices. The recoveries of spiked water and sediment samples were 89.3%–101.4% and 77.3%–92.1%, respectively. The detection limits of this method for four analytes in sediment samples and water samples were 0.1–0.5 ng·L−1 and 0.6–0.8 ng·L−1, respectively. The limits of quantification were 0.4–1.8 ng L−1 and 1.9–2.6 ng g−1 dry weight (dw) for water samples and sediment samples, respectively. The established method was successfully applied in the determination of target hormones in surface water and sediment samples collected from Erhai Lake, China.

SIM chromatogram of sediment sample spiked at 25 ng g−1 dw, 4 g sediment sample spiked at 25 ng g−1 dw after MAE, SPE and derivatization procedure, target androgens and progestogen have good performance on separation resolution, chromatographic peak shape and detection sensitivity with less matrix interference.