Developing Partitioned Dispersive Liquid-Liquid Microextraction for Simultaneous Determination of Nitrofurans and Sulfonamides in Water Matrices

A simple, efficient, effective, and environmentally friendly partitioned dispersive liquid-liquid microextraction (PDLLME) combined with high performance liquid chromatography - diode array detection (HPLC-DAD) method has been developed for the simultaneous determination of nitrofurans and sulfonamides in water. The type and volume of the extraction solvent, type and volume of disperser solvent, pH, speed and time of vortex, concentration of salt, and centrifugation period were optimized. Under these conditions, enrichment factors between 37.5 and 190.4 were obtained. Good linearity was obtained for sulfaquinoxaline from 5 to 1000 & mu;g L-1 and 5 to 600 & mu;g L-1 for the other analytes, with the coefficients of determination (r2) ranging between 0.9978 and 0.9998. Intra-day and inter-day repeatability expressed as the relative standard deviation were between 1.90 and 8.87% and 2.87 and 9.43%. The limits of detection and quantification were from 0.31 to 0.82 & mu;g L-1 and 0.98 to 2.73 & mu;g L-1, respectively. The method was employed for the analysis of tap, ground, and river water. Recoveries from 89.42 to 108.27% with relative standard deviations from 1.47 to 8.93% were obtained. The developed method was used for monitoring the residues of these antibiotics in drinking and environmental water.