Keywords: estrogens, bio-beads, estrogen derivatisation, surface water, risk assessment, Australia, wastewater treatment, water pollution, water quality
Optimisation of analytical method for estrogen in surface water and primary risk assessment in South Creek
A very non-polar sorbent, polystyrene-divinyl-benzene (brand: biobeads supplied by BioRad, with 30∼50 mesh) was tested for its extraction efficiency of four target compounds, estrone, estradiol, ethynylestradiol and estriol, from larger volumes (8 l) of water samples. To achieve adequate sensitivity of instrumental analysis by GC/MS, an improved estrogen derivatisation method was developed. For the simultaneous determination of the four estrogens, 50 ?l BSTFA+1% TMCS and 50 ?l pyridine was used for the derivatisation. Ions of different masses, 342 for estrone and 425 for 17α-ethynylestradiol, were formed using this protocol. The residual derivatisation reagents and pyridine were completely removed under a stream of dry nitrogen. Using the optimised extraction and derivatisation protocol, estrogen levels in the South Creek in Sydney and the Emigrant Creek in North of New South Wales were analysed. The possible contribution of the discharges from wastewater treatment plant as a source of estrogens is discussed.