AWWA WQTC64030

The objective of this work was to investigate the presence of some pharmaceuticals and personal care products (PPCP) in an effluent of a hospital corresponding to a population of approximately 100,000 inhabitants. Compounds belonging to different therapeutical classes have been considered such as anti-inflammatories (ibuprofen, naproxen, diclofenac), tranquilizers (diazepam), anti-epileptics (carbamazepine) and b-blockers. The soluble content of the fragrances, anti-inflammatories, carbamazepine and diazepam was determined after solid-phase extraction (SPE) of 500 ml samples using 60 mg OASIS HLB cartridges (Waters, Milford, MA, USA). Meclofenamic acid and dihydrocarbamazepine were added to the samples as surrogate standards. All compounds were quantitatively eluted from the cartridge using 3ml of ethyl acetate. This extract was then divided into two fractions: one of them was used for the direct determination of the soluble content of carbamazepine, diazepam and fragrances; the second one was employed for the determination of the anti-inflammatory species. In this case compounds were silylated previously to their gas chromatographic separation according to a previously published method. In both cases, GC/MS was used to determine the concentration of the investigated compounds in the SPE extract. In the cases of galaxolide and tonalide, complementary methodology was used to determine the overall amount present in samples containing solids: the total load. A previously developed method based on an SPME (Solid Phase Micro Extraction) technique using PDMS/DVB fiber was used for this purpose. The whole sample, including the soluble fraction and the solid particles, was thermostatized and magnetically stirred during the extraction process. The SPME fiber was exposed to the headspace over the sample. After the sampling time (30 min), the fiber was desorbed into the GC injector and GC-MS analysis was performed. Antibiotics, X-ray contrast media and estrogens were analyzed in Barcelona by the group of Dr. D. Barcel¿¿. For the first two groups, analyses were carried out by LC electrospray tandem MS after an enrichment step using an SPE method and elution with methanol Estrogens were analyzed by GC (ion trap) MS/MS after an enrichment step using an SPE method, elution with acetone and derivatization with MSTFA/DTE/TMSI for 1 h at 60 8C. Values given for the different samples of the STP considered in this work correspond to the mean value of two aliquots of each composite sample. HPLC¿¿¿MS was applied using a Hewlett-Packard (now Agilent Technologies, Palo Alto, CA, USA) Series 1100 HPLC/MSD system. An ammonium formate/formic acid buffer (10 mM, pH 3.7) aqueous phase and acetonitrile were used to produce a multi-step binary elution gradient. The flow rate was 0.200 mL/min, and all flow was directed to the mass spectrometer. Separations were made using a Metasil Basic 3 µm, 150mm ¿¿ 2.0 mm, C18 analytical column coupled to either a Metasil Basic Safeguard (MetaChem Technologies), 3 _m, 2.0mm guard column, or NewGuard RP-18, 7 µm, 15mm ¿¿ 3.2mm guard column (Perkin-Elmer). Includes 26 references, tables.