Ionic liquid-salt aqueous two-phase extraction coupled with high-performance liquid chromatography with ultraviolet detection was developed for the determination of sulfonamides in water and food samples. In the procedure, the analytes were extracted from the aqueous samples into the ionic liquid top phase in one step. Three sulfonamides, sulfamerazine, sulfamethoxazole, and sulfamethizole were selected here as model compounds for developing and evaluating the method. The effects of various experimental parameters in extraction step were studied using two optimization methods, one variable at a time and Box–Behnken design. The results showed that the amount of sulfonamides did not have effect on the extraction efficiency. Therefore, a three-level Box–Behnken experimental design with three factors, which combined the response surface modeling, was used to optimize sulfonamides extraction. Under the most favorable extraction parameters, the detection limits (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target compounds were achieved within the range of 0.15–0.3 ng/mL and 0.5–1.0 ng/mL from spiked samples, respectively, which are lower than or comparable with other reported approaches applied to the determination of the same compounds. Finally, the proposed method was successfully applied to the determination of sulfonamide compounds in different water and food samples and satisfactory recoveries of spiked target compounds in real samples were obtained.
Li JD, Cai YQ, Shi YL, Mou SF, Jiang GB (2007) J Chromatogr A 1216:3372–3379Google Scholar
Wom SY, Lee CH, Chang HS, Kim SO, Lee SH, Kim DS (2011) Food Chem 22:1101–1107Google Scholar
Pharmacologically active substances and their classification regarding maximum residue limits in foodstuffs of animal origin (2009) Commission Regulation No. 37/2010, European Community. Off J Eur Union L 15: 1–72Google Scholar
The Maximum Residue Limit in Food of Animal Origin established by Ministry of Agriculture of P.R. China (2003) Chin J Vet Drug 37:15Google Scholar