HPLC–DAD–FLD Determination of Veterinary Pharmaceuticals in Pharmaceutical Industry Wastewater with Precolumn Derivatization Using Fluorescamine

A simple and robust method suitable for routine analysis of pharmaceuticals from different classes in pharmaceutical industry wastewater samples is presented. Seven veterinary pharmaceuticals (antibiotics and anesthetic) were simultaneously isolated from a highly complex wastewater matrix. Target compounds were three sulfonamide antibiotics (sulfaguanidine, sulfadiazine, and sulfamethazine), three fluoroquinolone antibiotics (ciprofloxacin, enrofloxacin, norfloxacin), and one anesthetic, procaine. The investigated compounds were simultaneously pre-concentrated and cleaned up by solid-phase extraction using Strata-X extraction cartridges. The analysis was performed using liquid chromatography (LC) with diode array and fluorescence detectors connected in series to the chromatographic system. LC separation was performed on a C18 modified column (Phenomenex) with a gradient elution of mobile phase (0.1 % acetic acid in water and 0.1 % acetic acid in acetonitrile) in 25 min at 30 °C. Recoveries ranged from 86.9 to 110 % with relative standard deviations below 10.1 %. Method limits of quantification were in the range of 0.005–0.1 μg L^?1 depending on the fluorescence intensity after precolumn derivatization by fluorescamine.