Solid-phase microextraction with on-fiber silylation for simultaneous determinations of endocrine disrupting chemicals and steroid hormones by gas chromatography-mass spectrometry

Based on solid-phase microextraction (SPME) and on-fiber silylation, a method for simultaneous determinations of exogenous endocrine disrupting chemicals (EDCs) and endogenous steroid hormones in environmental aqueous and biological samples by gas chromatography-mass spectrometry (GC-MS) was developed. The selected target compounds were: octylphenol (OP), technical grade nonylphenol (t-NP), diethylstilbestrol (DES), dehydroisoandrosterone (DEHA), estrone (E1), 17beta-estradiol (E2), testosterone (T) and pregnenolone (PREG). The optimization of operating conditions influencing the performances of SPME and derivatization were studied in detail. The average correlation coefficient of the calibration curves of the target compounds was 0.9968 and the linear ranges of most compounds spanned over three orders of magnitude. The LOD/(LOQ) values of the target compounds in river water and blood serum were in the range of 0.002-0.378/(0.008-1.261) microg L(-1) and 0.004-0.474/(0.013-1.579) microg L(-1), respectively, which were a bit higher than those in the pure water due to matrix effects. The developed method was applied to the determinations of target compounds in real samples. Exogenous OP, t-NP and DES were at 0.15, 4.67 and 0.02 microg L(-1) in river water and 3.21, 12.17 and 0.15 microg L(-1) in fish blood serum. Natural steroid hormones E1, E2 and T were at 0.18, 0.10 and 5.55 microg L(-1) in river water, and in female fish serum, E1, E2 and PREG were at 1.61, 1.08 and 4.58 microg L(-1), respectively. The proposed SPME method was compared with traditional SPE procedure and the results found using both methods were in the same order of magnitude and both are quite agreeable.