Development and Validation of an Analytical Method for the Detection and Quantification of Bromazepam, Clonazepam and Diazepam by UPLC-MS/MS in Surface Water

The development of analytical methods capable of determining micropollutants is essential for quality control of drinking water. Benzodiazepines, a class of pharmaceuticals with anxiolytic properties, have received increasing attention as micropollutants. The purpose of this study was to develop an analytical method for determination of three benzodiazepine drugs (bromazepam, clonazepam and diazepam) in surface water. For the extraction of the matrix analytes, SPE cartridges (C18, 500 mg/3 mL) were used. The method was validated according to the quality criteria of the USEPA 8000D Validation Guide. The developed and validated method showed recovery values between 57 and 100%, RSD 0.9949. LD ranged between 2.70 and 5.00 ng L−1 for bromazepam and clonazepam respectively whereas LQ was 0.01 μg L−1 for all analytes. The matrix affected the signal intensity of clonazepam thus evidencing the matrix effect by analysis statistic (F test).