Determination of sterols and steroid hormones in surface water and wastewater using liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry

Abstract

The development and optimization of an analytical method for simultaneous extraction, determination and reliable confirmation of twenty steroids from different classes (human/animal and plant sterols, and natural and synthetic steroid hormones) in environmental water and wastewater at ng L-1 levels are described. Water samples were prepared using solid-phase extraction and extracts were analyzed by liquid chromatography-linear ion trap-tandem mass spectrometry. Improved instrumental method was developed for complete chromatographic separation of analytes with identical fragmentation reactions, based on the Use of a single C8 column and acetonitrile as organic solvent in the mobile phase. The optimized method provided high recoveries (70-114%) for both water matrices with the RSDs generally lower than 20%. Low limits of detection were achieved for both surface water (0.7-15.0 ng L-1) and wastewater (1.7-15.0 ng L-1). Method displayed good linearity in the tested concentration ranges. As a result of method application to real water samples, cholesterol was detected in all fifteen analyzed river water samples (in the concentration range 176-5162 ng L-1) and all seven wastewater samples (1092-4808 ng L-1). Also, coprostanol, stigmasterol, campesterol, beta-sitosterol and sitostanol were found in the investigated samples. Steroid hormones were not detected in any of the analyzed water samples.