OPTIMIZATION OF DERIVATIZATION OF ACIDIC DRUGS FOR ANALYSIS BY GC-MS AND ITS APPLICATION FOR DETERMINATION OF DRUG RESIDUES IN WASTEWATER.

This article is focused on optimization of derivatization of acidic drugs from the group of non-steroidal anti-inflammatory drugs (NSAID): salicylic acid, ibuprofen, naproxen, ketoprofen and diclofenac. Derivatization is a necessary step for analysis of pharmaceuticals by GC. MSTFA (A'-methyl- A-(trimethylsilyl)trifluoroacetamide) and BSTFA (N,0- bis(trimethylsilyl)trifluoroacetamide) were used as a derivatization reagents and tested under different conditions: volume, temperature and time of derivatization. Results of optimization were compared and optimized conditions were successfully applied for analysis of real samples of wastewater. Wastewater samples were collected from influent and effluent of wastewater treatment plant (WWTP). The whole analytical procedure involved solid phase extraction (SPE), optimized derivatization and analysis by GC-TOF MS. Limits of detection (LOD) ranged between 8.9 - 71.6 ng.L^-1 and limits of quantification (LOQ) ranged between 29.5 - 238.7 ng.L^-1 depending on the specific compound. Concentration of selected drugs in real samples of wastewater varied from 0.1 to 30 pg.L^-1 in influent and from 0.05 to 2 pg.L^-1 in effluent, depending on the compound. [ABSTRACT FROM AUTHOR]