Novel passive sampling for steroid hormones in aquatic environments using DGT and the ERE-CALUX bioassay - Poster @ ChemCYS 2018

Adverse effects of steroid estrogens and endocrine disrupting chemicals
(EDCs) or endocrine active chemicals (EACs) can occur at relatively low
concentrations in the aquatic environment. Monitoring these compounds as
encouraged by the European Water Framework Directive (WFD, 2013/39/EU)
demands efficient, simple and sensitive techniques to detect and quantify
these emerging pollutants of concern (EPOCs).

Here, a novel sampling technique of diffusive gradients in thin films (DGT)
combined with the estrogen responsive element - chemically activated
luciferase gene expression (ERE-CALUX) bioassay was developed for in situ
pre-concentration and estrogenic effect measurement of steroids in the
aquatic environment at environmentally relevant levels. In this study, the
performance of this novel method was assessed, with 17β-estradiol (E2) as
a model estrogen in a single compound solution, VM7Luc4E2 cells (formerly
BG1Luc4E2) as ERE-CALUX bioassay cells and XAD 18 resin gel as a binding
phase.

Laboratory tests showed that DGT components and the experimental matrix
do not influence the estrogenic activity of ERE-CALUX cells. XAD 18 showed
sufficiently high capacity for the binding of E2 and that the measured
effective diffusion coefficient of E2 in an agarose diffusive gel was 4.7 ×
10-6 cm2/s at 25°C. The detection limit of this novel method was significantly
lower than the one obtained from active sampling combined with GC/MS
and LC/MS analysis (0.1-7.0 ng/L) described in literature and reached 0.026
± 0.003 ng/L of E2 for a one-day deployment. The method was independent
of pH (5-8), ionic strength (0.001-0.1M) and dissolved organic matter
concentrations (0-30 mg/L). The combination of diffusive gradients in thin
films with ERE-CALUX is an effective tool for pre-concentrating steroid
estrogens and possibly also in the monitoring of estrogenic activity in
natural waters.