Parameters for ultra-performance liquid chromatographic/tandem mass spectrometric analysis of selected androgens...

This study is a response to the relative lack of literature concerning androgenic versus estrogenic hormones in environmental matrices. Methods of solid-phase extraction (SPE) and ultra-performance liquid chromatography/(electrospray ionization) tandem mass spectrometry (UPLC/(ESI)MS(2)) were developed in parallel for detection of four natural androgens and four commonly studied estrogens, three natural and one synthetic, in aqueous matrices. Instrumental parameters were optimized and compared between hormone classes, with application to spiked deionized water, pond water, and wastewater. Differences in behavior of the hormone classes were explained by the lesser electron delocalization and polarity of the androgens versus estrogens, with testosterone behaving intermediately. In general, androgens required a stronger UPLC mobile phase with a slower flow rate and ESI of the opposite polarity with modifier addition (0.9 mM ammonium acetate). Instrumental detection limits of androsterone, epiandrosterone, and dehydroepiandrosterone were 1-2 orders of magnitude greater than those of testosterone and the estrogens, but androgens were more recalcitrant to dispersal during extract storage. Manageable matrix interference was encountered in pond water samples. That introduced in treated wastewater was evident as coeluting peaks and skewed compound recoveries. Ion suppression of the estrogen surrogate and enhancement of the androgen were observed. The analytical rapidity afforded by UPLC proved beneficial in the analysis of simple matrices but should be considered secondary to enhanced resolution in complex environmental samples.