Simultaneous determination of macrolides, sulfonamides, and other pharmaceuticals in water samples by solid‐phase extraction and LC‐(ESI) MS

This paper describes a method for determining 11 pharmaceuticals in various water sources by SPE followed by LC‐(ESI) MS. SPE was carried out with Oasis TM HLB and the recoveries were 33–67% for 250 and 100 mL sewage water, 55–77% for 500 mL river water and 72–98% for 1 L tap water, with the exception of sulfamethoxazole and omeprazole which showed lower recoveries in all kinds of sample. The LODs in river water were of 5 ng/L for sulfadiazine, trimethoprim, sulfamethazine, sulfamethoxazole, and ranitidine and 10 ng/L for the other compounds. The highest concentrations found in river waters were for sulfamethoxazole (50 ng/L). In influent sewage waters, ranitidine was the most commonly detected compound with a maximum value of 0.24 μg/L.