样品采集于棕色高密度聚乙烯瓶或玻璃瓶中，尽快进行前处理，于4℃保存不超过7 d。水样经0.45 μm滤膜过滤，移取1 L，加入1 g的Na₂EDTA，用0.1 mol·L^-1 NaOH溶液调节样品溶液的pH至6.0，采用OASIS HLB固相萃取柱对待测物进行富集萃取，用10 mL水洗涤小柱，真空干燥10 min，再用10 mL甲醇洗脱待测物，收集洗脱液，氮吹浓缩至干，用初始流动相定容至1 mL，加入1.00 mg·L^-1的内标混合溶液50 μL，过0.20 μm亲水性聚丙烯滤膜后，采用HYPERSIL GOLD C₁₈色谱柱（100 mm×2.1 mm，1.9 μm）分离待测物，以0.05%（体积分数）甲酸溶液和甲醇为流动相进行梯度洗脱，质谱分析中采用电喷雾正离子源和多反应监测模式。19种磺胺类抗生素的线性范围均为2.0~100 μg·L^-1，检出限（3.143s）在0.6~2.0 ng·L^-1之间。加标回收率为77.6%~134%，测定值的相对标准偏差为1.9%~11%。方法应用于测定地表水和养殖企业废水中的抗生素残留，地表水中仅检出两种目标物，质量浓度分别为2.60，2.10 ng·L^-1，养殖企业废水检出7种目标物，质量浓度在2.82~34.3 ng·L^-1之间。

The water samples were collected in brown high-density polyethylene bottles or glass bottles and pretreated as soon as possible, and stored at 4℃ for no more than 7 days. The collected sample was filtered through a 0.45 μm filter and 1 g of Na₂EDTA was added into 1 L of the sample. The pH of the sample solution was adjusted to 6.0 with 0.1 mol·L^-1 NaOH solution, and the OASIS HLB solid phase extraction column was used for enrichment and extraction of the analytes. After the column was washed with 10 mL of water and dried in vacuum for 10 min, the analytes was eluted with 10 mL of methanol and the eluate was collected and concentrated by nitrogen-blowing to dryness. The residue was diluted to 1 mL with the initial mobile phase, and 50 μL of 1.00 mg·L^-1 mixed internal standard solution was added, then the solution was filtred with 0.20 μm hydrophilic polypropylene membrane. The analytes were seperated on a HYPERSIL GOLD C₁₈ column (100 mm×2.1 mm, 1.9 μm), with 0.05% (volume fraction) formic acid solution and methanol as the mobile phase for gradient elution. Electrospray positive ion source and multiple reaction monitoring mode were used in mass spectrometry analysis. Linearity range of 19 sulfonamide antibiotics was same 2.0-100 μg·L^-1, with detection limits (3.143s) in the range of 0.6-2.0 ng·L^-1. Values of recovery obtained by standard addition method ranged from 77.6% to 134%, and RSDs (n=6) ranged from 1.9% to 11%. The method was applied to the determination of antibiotic residues in the surface water and wastewater from a farming enterprise, only two targets with mass concentrations of 2.60, 2.10 ng·L^-1 were found in the surface water, and 7 targets with mass concentrations in the range of 2.82-34.3 ng·L^-1 were found in the wastewater from a farming enterprise.