Novelty aqueous two-phase extraction system based on ionic liquid for determination of sulfonamides in blood coupled with high-performance liquid chromatography

Ionic liquid/anionic surfactant aqueous two-phase system was developed and applied for the extraction of sulfonamides in blood. High-performance liquid chromatography was applied to the determination of the analytes. The blood sample was centrifuged and added to sodium dodecyl sulfate (SDS), ionic liquid 1-Hexyl-3-MethylImidazolium Chloride([C6MIM] Cl), K2HPO4. After the resulting mixture was ultrasonically shaken and centrifuged, the aqueous two phase system was formed and analytes were extracted into the upper phase. The parameters affecting the extraction efficiency, such as volume of ionic liquid, amount of sodium dodecyl sulfate, ionic strength, pH value of system, extraction time and temperature were investigated. The limits of detection of Sulfamethyldiazine (SMZ), Sulfamethizole (STZ), sulfachlorpyridazine (SCP), sulfamethoxazole (SMX) and Sulfisoxazole (SSZ) were 3.29, 4.13, 3.74, 2.45 and 3.60 μg L− 1, respectively. When the present method was applied to the analysis of real blood samples, the recoveries of analytes ranged from 85.5 to 110.9% and relative standard deviations were lower than 6.9%.