Use of solid-phase extraction in various of its modalities for sample preparation in the determination of estrogens and progestogens in sediment and water

The environmental analysis of estrogens and progestogens at physiologically active concentrations (low ng/l range) requires the use of very sensitive and selective methods, which, in most cases, make necessary an extraction/purification step. In this study, various procedures for the determination of several estrogens (estriol, estradiol, ethynyl estradiol, estrone, and diethylstilbestrol) and progestogens (progesterone, norethindrone, and levonorgestrel) in environmental matrices, including water and river sediment, are described. In all procedures, final analysis of the target compounds is performed by reversed-phase liquid chromatography–diode array detection–mass spectrometry, whereas sample preparation always includes a solid-phase extraction (SPE) step. For this SPE step, various types of sorbents, protocols, and devices have been used, and their respective advantages and disadvantages are discussed. For the off-line SPE of estrogens and progestogens from water samples, a syringe type cartridge LiChrolut RP-18 (500 mg) was selected out of two other sorbents — LiChrolut EN (200 mg) and Isolut ENV (500 mg) — for use with the automated sample preparation instrument ASPEC XL. For the on-line SPE and analysis of water samples the 10 mm×2 mm I.D. HySphere-Resin-GP cartridge, was preferred to the C18 Baker, the PLRP-S, and the Oasis HLB, for use with the Prospekt system. A completely manual protocol based on the use of Sep-Pak C18 Plus cartridges was developed for purification of sediment extracts. All procedures were shown to be linear over a wide range of concentration, exhibited satisfactory repeatability and accuracy, and reached limits of detection usually in the low ng/l and ng/g range. Comparatively, the on-line method was shown to be advantageous in terms of automation and general method performance.