Fully-automated on-line solid phase extraction coupled to high-performance liquid chromatography–tandem mass spectrometric analysis at sub-ng/L levels of selected estrogens in surface water and wastewater

Abstract

A fully-automated on-line solid phase extraction liquid chromatographic/electrospray ionization tandem mass spectrometric method for the analysis of estrone (E1), 17-β-estradiol (β-E2), 17-α-ethinylestradiol (EE2), 17-α-estradiol (α-E2) and estriol (E3) in surface water and wastewater was developed. The method showed a very good linearity from 250ng/L down to compound specific quantification limits, which were included between 0.25 and 2.00ng/L. These limits were obtained with 2.5mL aliquots of injected sample and the total analysis time per sample was slightly less than 10min. Under these conditions, detection limits were 0.15ng/L for E1, 0.31ng/L for β-E2, 0.52ng/L for EE2, 0.59ng/L for α-E2 and 0.95ng/L for E3. The method reliability was tested on different kinds of real samples spiked with the estrogens, obtaining recoveries approximately included between 71 and 95%. The application to samples collected in rivers, lakes and wastewater treatment plants evidenced the presence of the investigated compounds at sub-ng/L or low ng/L concentration levels.