Parameters for ultra-performance liquid chromatographic/tandem mass spectrometric analysis of selected androgens versus estrogens in aqueous matrices.

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.

Microwave-assisted solvent extraction of solid matrices and subsequent detection of pharmaceuticals and personal care products (PPCPs) using gas chromatography-mass spectrometry.

Concentrations of pharmaceuticals and personal care products (PPCPs) in natural solids remain largely unknown. Contributing to this, is a lack of methods permitting the simultaneous detection of the diverse, low-level contaminants present in these complex matrices. We have developed a microwave-assisted solvent extraction (MASE)-based method targeting seven diverse PPCPs (caffeine, 17beta-estradiol, ibuprofen, ketoprofen, musk ketone, naproxen, and triclosan) and a molecular marker for fecal waste (epicoprostanol). The method consisted of optimizing the following variables: derivatization of the polar target analytes, silica gel open column clean-up, and gas chromatographic-mass spectrometric (GC-MS) analysis of sample extracts for analysis and detection of the compounds noted above. Testing of the method on spiked soil allowed for 89.6+/-2.89% recovery of three target compounds and 25.0+/-1.93% recovery of five of the compounds. Although the latter recoveries were low, the precision across all recoveries was high, suggesting good reproducibility in application of the method. Furthermore, we suspect that matrix effects are likely responsible for the lower recoveries. Techniques with the exclusive incorporation of organic solvents were found inapplicable in the study of a pharmaceutical salt, diphenhydramine HCl. Application of the developed method to sediment collected directly downstream of the effluent pipe of a wastewater treatment plant allowed detection of ibuprofen, naproxen, ketoprofen, and epicoprostanol at ng-mug per gram dry weight concentrations. The observation of acidic pharmaceuticals, previously believed to exhibit insignificant sorption to solid matrices, in the tested sediment samples, coupled with application of biosolids for agricultural purposes, demonstrates the need for expanded investigation of PPCP contamination of natural solid matrices.