Enhancement for trace analysis of sulfonamide antibiotics in water matrices using bar adsorptive microextraction (BAμE)

In this study, the enhancement for trace analysis of sulfonamide antibiotics (sulfathiazole, sulfamethoxazole and sulfadimethoxine) and trimethoprim in water matrices is proposed using bar adsorptive microextraction combined with micro-liquid desorption followed by high-performance liquid chromatography with diode array detection (BAμE-μLD/HPLC-DAD). By comparing different polymers and activated carbons as sorbent coatings for BAμE, the polystyrene-divinylbenzene polymer (PS-DVB) showed the best selectivity for the compounds under study. Assays performed through BAμE(PS-DVB)-μLD on 25 mL of ultrapure water samples spiked at the 8.0 μg L⁻¹ level showed recoveries ranging from 63.8 ± 1.5% to 84.2 ± 1.9%, under optimized experimental conditions. The validated method provided satisfactory limits of detection (0.08–0.16 μg L⁻¹) and good linear dynamic ranges (0.16–8.00 μg L⁻¹) with determination coefficients higher than 0.9958. The proposed analytical methodology was applied to real matrices, such as tap, estuarine and wastewater samples using the standard addition method. It showed to be easy to implement, with good reproducibility, sensitivity and requiring small amount of sample. Furthermore, negligible consumption of organic solvents was used in compliance with the green analytical chemistry principles. When compared to other well-established microextraction approaches, BAμE demonstrated better performance concerning recovery yields and sensitivity.