Search

Salting-out homogenous extraction followed by ionic liquid/ionic liquid dispersive liquid-liquid micro-extraction system was developed and applied to the extraction of sulfonamides in blood. High-performance liquid chromatography was applied to the determination of the analytes. The blood sample was centrifuged to obtain the serum. After the proteins in the serum were removed in the presence of acetonitrile, ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, dipotassium hydrogen phosphate, ionic liquid 1-Hexyl-3-methylimidazolium hexafluorophosphate were added into the resulting solution. After the resulting mixture was ultrasonically shaken and centrifuged, the precipitate was separated. The acetonitrile was added in the precipitate and the analytes were extracted into the acetonitrile phase. The parameters affecting the extraction efficiency, such as volume of ionic liquid, amount of dipotassium hydrogen phosphate, volume of dispersant, extraction time and temperature were investigated. The limits of detection of sulfamethizole (STZ), sulfachlorpyridazine (SCP), sulfamethoxazole (SMX) and Sulfisoxazole (SSZ) were 4.78, 3.99, 5.21 and 3.77 μg L −1 , respectively. When the present method was applied to the analysis of real blood samples, the recoveries of analytes ranged from 90.0% to 113.0% and relative standard deviations were lower than 7.2%. [ABSTRACT FROM AUTHOR]

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([C 6 MIM] Cl), K 2 HPO 4 . 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%. [ABSTRACT FROM AUTHOR]

Abstract: Ultrasound-assisted ionic liquid/ionic liquid-dispersive liquid–liquid microextraction (UA-IL/IL-DLLME) high-performance liquid chromatography was developed and applied to the extraction, separation and determination of sulfonamides in infant formula milk powder samples. The hydrophobic IL and hydrophilic IL were used as extraction solvent and dispersion solvent, respectively. The extraction procedure was induced by the formation of cloudy solution, which was composed of fine drops of [C6MIM][PF6] dispersed entirely into sample solution with help of [C4MIM][BF4]. The purification of sample and concentration of target analytes were performed simultaneously. The introduction of ion-pairing agent (NH4PF6) was beneficial to the improvement of recoveries for IL phase and analytes. The experimental parameters of the UA-IL/IL-DLLME, including concentration of [C6MIM][PF6] and [C4MIM][BF4] in sample solution, ultrasound extraction time, pH value of sample solution and amount of ion-pairing agent (NH4PF6), were evaluated. The limits of detection for sulfamerazine, sulfamethizole, sulfachlorpyridazine, sulfamonomethoxine, sulfmethoxazole and sulfisoxazole were 2.94, 9.26, 16.7, 5.28, 3.35 and 6.66μgkg−1, respectively. When the present method was applied to the analysis of infant formula milk powder samples, the recoveries of the analytes ranged from 90.4% to 114.8% and relative standard deviations were lower than 7.5%. The proposed method was compared with the ionic liquid-homogeneous liquid–liquid microextraction, ionic liquid-ultrasound-assisted emulsification–microextraction and ionic liquid-temperature-controlled-DLLME. The results indicated that the proposed method is effective for the extraction of the sulfonamides in milk powder samples. [Copyright &y& Elsevier]