Simultaneous analysis of four sulfonamides in chicken muscle tissue by HPLC.

The aim of this study was to develop a simple high-performance liquid chromatography (HPLC) with UV detection method for the determination of four sulfonamides in chicken muscle tissue. The sulfonamides were extracted with acetonitrile, acetone and dichloromethane. Separation was carried out on a C18 column using as the mobile phase a mixture of 6‰ disodium hydrogen phosphate and methanol. The analytes were detected by UV in one run. Calibration curves were linear with very good correlation coefficients for concentration ranging from 30 to 150 µg kg(-1). The limits of detection (LOD) for sulfonamides ranged from 6.5 to 0.14 µg kg(-1). The recovery for spiked chicken muscle with 50-150 µg kg(-1) was more than 70%. The relative standard deviations (RSDs) of the sulfonamides for six measurements at 50, 100 and 150 µg kg(-1) were less than 15%. These parameters met the European Union criteria for method validation. The results were confirmed by LC-MS/MS using multiple reaction monitoring as the operating mode. Confirmation required the retention times of the analytes to be within ±2.5% of the retention times of the standards, the presence of the parent ion and two characteristic fragment ions (product ions) per analyte, as well as the relative ion abundance ratios of the fragment ions corresponding to ratios obtained for the standards, within permitted limits. The transition of two common product ions at m/z 155.7 and 107.5 were monitored for all sulfonamides. Each of the analytes, in all tested samples, met the confirmation criteria. Thus, the applicability of the HPLC-UV method for routine analysis of chicken muscle tissue was demonstrated.