Abstract:We developed a confirmatory detection method for 19 sulfonamide drug residues in foods of animal origin, which were double-purified using dialysis, followed by capture on a sulfonamide affinity column, and detected and analyzed using ultra-high performance liquid chromatography-tandem mass spectrometry. Samples were extracted with 80 % acetonitrile (0.2 % formic acid). Extracts were partially purified using dialysis, and sulfonamides were captured on a column (Speedy Prep®-Sulfa), then separated using an ACQUITY UPLC BEH C18 column. Gradient elution was carried out using a gradient of 0.2 % aqueous formic acid and methanol as the mobile phase. Mass spectrometry was performed using electrospray positive ion mode and multiple reaction monitoring modes. An external standard method was used for quantitative analysis. The results indicated that the sulfonamide capture column in this method could complete purification within 30 sec, and the entire pretreatment process required less than 10 min. The 19 sulfa drug concentrations were within their linear range (correlation coefficient r≥0.999 1), the limit of detection was 1.00~2.00 μg/kg, and the limit of quantification was 2.50~5.00 μg/kg. Pork, beef, eggs, shrimp, chicken skin, and pork liver were spiked at 5, 10, and 50 μg/kg, and average recovery ranged from 74.56% to 119.28%, with relative standard deviations (RSD, n=6) ranging from 0.91% to 14.16%, indicating good recovery and precision. The method described herein confers several advantages, including simple operation, high accuracy, excellent reproducibility, and suitability for quantifying sulfonamides in pork, beef, eggs, shrimp, chicken skin, and pork liver.
