An improved pretreatment method for efficient detection of antibiotic residues in aquatic products by LC-MS/MS

Antibiotics are a class of compounds that are effective against bacterial infections and are widely used in aquaculture. Herein, a method based on high performance liquid chromatography coupled with tandem mass spectrometry was developed to detect nine classes of 116 antibiotics in aquatic products. The antibiotics were extracted in two steps using 1 % formic acid-acetonitrile with 0.1 mol/L Na₂EDTA-Mcllvain buffer solution and acetonitrile, purified using Captiva EMR-Lipid, and separated with an ACQUITY UPLC®HSS T₃ column (100 mm × 2.1 mm, 3.5 μm) using acetonitrile and 0.1 % formic acid with 5 mM ammonium acetate as mobile phase for gradient elution. Calibration curve from 0.10 to 100 ng/mL exhibited good correlation coefficient (R²>0.99) for quantification. The analytical performance of the developed method was satisfactory, with limits of quantification ≤ 5.00 ng/g for detecting of antibiotics in aquatic products. The recoveries of the 116 antibiotics ranged from 60.57 % to 127.33 %, with precision (expressed as relative standard deviation) of < 30.20 %. All parameters showed acceptable values and conformed to the Commission Decision 2021/808/EC criteria. When compared with other techniques, the developed method meets the quantitative requirements of high-throughput analysis and can simultaneously analyze 116 antibiotics in aquatic products.