Hi Albert......

For the extraction of estrogens from environmental interest in water samples, methods that include solid phase extraction (SPE) using C18 as adsorbents, are widely used.

For quantification, HPLC-UV and HPLC - Fluorescence have high sensitivity, selectivity, and linearity of the analytical response for these analytes.

If your referring to environmental samples, the compounds are probably very dilute as they often are and so the first step is likely concentration and cleanup.

The so called "concentration effect" may need to be used to build up and trap enough analyte for analysis onto a reversed phase column. This typically means using very low % organic mobile phase (such as 2% organic) to pump large volumes of the water over a C18 column to trap the componds. Then a high % organic can be used to either elute and recover the compounds for a separate analysis. The use of SPE-C18 cartidges is based on the same principal ("catch and release") but cannot trap nearly as much. Which to use depends upon how dilute your samples are. Concentration effect should work very well for estrogenic compounds since, even if dissolved in water, most estrogen active compounds have some lipophilicity because that is a required property to bind estrogen receptors (ER-alpha and ER-beta).

Quantitation by whatever detection method will likely require HPLC separation and reference standards.

Extraction: SPE using C18 Silica.

Instrumental Analysis: LC-MS or LC-MS/MS

These are the best options for trace analysis in waters.

Regarding SPE for trace analysis in waters, Oasis HLB (Waters) is one of the very good options for extracting polar analytes from environmental water

thanks a lot for all the useful data. Cheers!