LAUSR

A rapid and simple high-performance liquid chromatography-ultraviolet method was developed for the separation and quantification of 15 sulfonamides (SAs) in foods of animal origin without the need of clean-up procedure. A mixture of acetonitrile-formic acid-ammonium acetate-water was used as the mobile phase to separate 15 SAs on a C18 column with gradient. The selected SAs were separated completely from the matrix mixture based on different retention behaviors at different concentration of acetonitrile. The effects of the additive of formic acid and ammonium acetate in mobile phases on the separation of SAs were also investigated. The additive can greatly improve the resolution between SAs and impurities, so that the SAs can be quantified directly under the optimized chromatographic condition the sample preparation which does not need extra sample clean-up procedure. Complete baseline separation of 15 SAs was achieved in <40 min, the linear range is 0.01-130 μg/mL with a correlation coefficient R2-value > 0.999. Excellent method reproducibility was found by intra- and inter-day precisions with the relative standard deviation <9.5%. The detection limit was <11.0 ng/mL and it can be used for routine screening of the SA residues in foods of animal origin.