Determination of Sulfonamides in Water Sample Using Ionic Liquid-based Single Drop Microextraction Coupled with High Performance Liquid Chromatography

A novel method was developed for the determination of seven sulfonamides in water samples using ionic liquid-based single drop microextraction coupled with high performance liquid chromatography.The influence of extraction parameters including extraction solvent,volume of extraction solvent,extraction time,stirring speed,pH value,NaCl concentration of sample solution and extraction temperature were investigated.Using 9 μL 1-butyl-3-methylimidazolium hexafluorophosphate([C4MIM][PF6]) as extraction drop,10.0 mL aqueous sample with 0.33 g/mL NaCl(pH 3) was extracted for 35 min with stirring at 300 r/min at 50 ℃.Under the optimal conditions,good linear relationships were obtained in the sulfonamides concentrations of 0.005-2.000 mg/L with the correlation coefficients of 0.9994-0.9998;the detection limits were 0.001-0.003 mg/L(S/N = 3) ;the enrichment factors of [C4MIM][PF6]for the seven sulfonamides were from 22 to 107;the RSD of matrix spiked samples were 3.1%-5.6%(n = 5).The proposed method was applied to the determination of the seven sulfonamides in tap,river,lake and waste water with recoveries of the seven sulfonamides in the range of 84.3%-106.0%.