Endocrine Disruptor Pharmaceutical Analysis Using Direct-Injection LC/MS/MS

摘要

A simple and rapid method has been developed to measure 27 compounds from a diverse group of pharmaceuticals, steroids, pesticides, and personal care productsrndirectly from water samples. The method utilizes direct injection of waterrnsamples into a liquid chromatograph/tandem mass spectrometer (LC/MS/MS).rnWater samples are sequentially acidified, filtered, and injected directly into thernLC/MS/MS system without extraction or concentration. Ionization isrnaccomplished using electrospray ionization (ESI) in both positive and negativernmodes and atmospheric pressure chemical ionization (APCI) in positive mode.rnInstrument detection limits (IDLs) for all target compounds were below 1.0 pg onrncolumn with corresponding method reporting limits from 10 – 25 ng/L. Thisrnmethod circumvents time-consuming extraction, concentration and clean-uprnprocedures, and requires sample volumes of less than 1 mL. In addition, thisrndirect-injection technique remains free of ion-suppression/enhancement effectsrnoften reported using LC/MS/MS with concentrated extracts. Samples werernanalyzed using both the direct injection technique and after solid-phase extractionrn(SPE) and the results compared. Significant ion-suppression and ionenhancementrnwere seen using the SPE extracts as well as low recoveries of some compounds, while the direct-injection technique did not exhibit such problems. This method was applied to a variety of water matrixes including wastewater effluents, drinking water, and surface and ground waters. The most commonly detected target compounds were carbamazepine, sulfamethoxazole, DEET, and gemfibrozil. Detectable concentrations ranged from 10 to >4,000 ng/L.