Analysis of Steroidal Compounds in Environmental Samples by Comprehensive Two-dimensional Gas Chromatography Time-of-flight Mass Spectrometry

Abstract

Steroidal compounds, especially human estrogens, have been shown to have an impact on aquatic ecosystems. Investigations at the Viikinmäki wastewater treatment plant in Helsinki revealed presence of these compounds in effluent waters (Kopperi et al. 2013)(88). The ability of steroids to adsorb on suspended wastewater particles during the treatment process can present a pathway into the environment and thus requires detailed research.

In this study, there has been an evaluation and optimization of several aspects in the analytical methodology developed by Kopperi. These aspects were as follows: Evaluation of a different type of solid-phase extraction specified for whole-water analysis, optimization of an eluent of a normal phase solid-phase extraction, evaluation of different injector port liners in the GCxGC-TOFMS and the optimization of three different solid particulates extraction methods. The improved method was used on three different types of environmental samples; sewage sludge, garden soil and lawn soil.

The Speedisk which was evaluated for the solid-phase extraction for whole-water analysis was not applicable due to clogging when loading effluent wastewater samples. The normal phase solid-phase extraction eluent was optimized to have 15 % acetone content in opposite to its original 5 % (88). The ultra-inert liners had no significant effect on the sensitivity on steroid species compared to normal liners. The most effective solid extraction method was the pressurized hot water extraction with about 20 times higher relative peak values for androsterone and about 4 times higher for estrone compared to the other extraction methods. The extraction method with highest through-put was the ultrasound-assisted extraction whilst the focused ultrasound-assisted extraction was performing inadequate in both through-put and extraction ability.

The environmental samples that were analyzed in this study were taken from dried sewage sludge and commercially available soil products produced by Metsäpirtin Multa which is run by the Helsinki Region Environmental Service Authority (HSY). The product contains soil elements from wastewater treatment plants and using the optimized method the measured concentrations of some estrogens in these samples were considered high compared to the predicted no-effect concentration for estrogens in soil.