Analysis of estrogens/hormones in drinking water using ESI/LC/MS coupled with solid phase extraction technology

Lee J. Yoo

Chemist Supervisor

Orange County Water District

10500 Ellis Ave. Fountain Valley

California, 92708

The occurrence of estrogens/hormones in drinking water, surface water and groundwater is largely dependent on location and treatment technology. High concentration of estrogens/hormones are commonly present in the effluents of wastewater and sewage treatment plants.  It has become more important to monitor these compounds in drinking water as well as the effluents of sewage treatment plants.  It is often required for the trace analysis of these compounds, especially for human hormones/estrogens present at sub- to low part-per-trillion levels in waters.  GC/MS/MS can provide sensitive and selective detection of these compounds, but it requires a time-consuming and labor-intensive sample derivatization process to be suitable for gas chromatographic analysis.  Recently, LC/MS and LC/MS/MS have become more attractive because they are able to provide high sensitivity and selectivity without the need of derivatization.

Orange County Water District (OCWD) has developed very sensitive and reliable detection method for estrogens/hormones from the different matrices of water samples using ESI/LC/MS coupled with new type of universal resin extraction disk.  The system was optimized for each target compounds with single ion monitoring and varied cone voltages to maximize the response and reproducibility.  Also the LC gradient method for the separation of these compounds was examined with different size particles of C18 columns from different manufactures.

The universal resin extraction technique generated excellent recoveries for the target compounds with 90% labor and solvent reduction.  The method detection limit for estrogens/hormones using ESI/LC/MS are sub parts per trillion for drinking water, surface water and reclaimed water samples.   The established method was effectively applied for the monitoring sub parts per trillion levels of estrogens/hormones from the wastewater treatment plant using medium pressure UV and micro membrane technology.