Quantification of Solute–Solute Interactions Using Negligible-Depletion Solid-Phase Microextraction: Measuring the Affinity of Estradiol to Bulk Organic Matter
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Date
2008Author
Neale, Peta A.
Escher, Beate I.
Schäfer, Andrea
Metadata
Abstract
The interaction of trace organic contaminants with bulk organic matter has implications for the
transport and behaviour of organic trace contaminants within the aquatic environment as well as
water and wastewater treatment processes. Partition coefficients (KOM) of the steroidal trace
organic contaminant estradiol were quantified for environmentally relevant concentrations of bulk
organic matter (12.5 mgC/L) using a full mass balance form of solid phase microextraction
(SPME). The results indicated that the method is successful and can be used at environmental
concentrations. Estradiol had the greatest affinity for bulk organic matter that contained phenolic
and benzoic acid ester groups, namely tannic acid, compared to organics containing predominately
carboxylic functional groups. The solution chemistry (pH) was found to influence the interaction, as
estradiol had a lower affinity for negatively charged and hydrophilic bulk organic matter. The
partition coefficients determined using SPME were consistent with partition coefficients derived
using solubility enhancement and fluorescence quenching measurements, confirming that SPME is
a powerful technique to quantify the affinity of estradiol for low concentrations of bulk organic
matter and trace contaminants. Further, this novel method can be applied to a range of trace
contaminants