AWWA WQTC59003

A simple and rapid method has been developed to measure 27 compounds from a diverse group of pharmaceuticals, steroids, pesticides, and personal care products directly from water samples. The method utilizes direct injection of water samples into a liquid chromatograph/tandem mass spectrometer (LC/MS/MS). Water samples are sequentially acidified, filtered, and injected directly into the LC/MS/MS system without extraction or concentration. Ionization is accomplished using electrospray ionization (ESI) in both positive and negative modes and atmospheric pressure chemical ionization (APCI) in positive mode. Instrument detection limits (IDLs) for all target compounds were below 1.0 pg on column with corresponding method reporting limits from 10 - 25 ng/L. This method circumvents time-consuming extraction, concentration and clean-up procedures, and requires sample volumes of less than 1 mL. In addition, this direct-injection technique remains free of ion-suppression/enhancement effects often reported using LC/MS/MS with concentrated extracts. Samples were analyzed using both the direct injection technique and after solid-phase extraction (SPE) and the results compared. Significant ion-suppression and ion-enhancement were 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 matrices including wastewater effluents, drinking water, and surface and groundwaters. The most commonly detected target compounds were carbamazepine, sulfamethoxazole, DEET, and gemfibrozil. Detectable concentrations ranged from 10 to >4,000 ng/L. Includes 27 references, tables, figure.