Chen Qian, Liu Yang, Xiao Li-Jun, Zou De-Yu, Liu Hai-Xue, Wu Hui-Hui
College of Horticulture and Landscape, Tianjin Agricultural University, Tianjin 300384, China.
College of Agronomy&Resources and Environment, Tianjin Agricultural University, Tianjin 300384, China.
Huan Jing Ke Xue. 2020 Feb 8;41(2):952-961. doi: 10.13227/j.hjkx.201907101.
An analytical approach was developed to simultaneously determine 13 antibiotics in sulfonamides, quinolones, and macrolides in leafy vegetables by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS). After optimizing extracted solutions, purification methods, and eluents of antibiotics in vegetable substrates, and taking into account the influence of environmental changes and experimental conditions on the results, the optimal experimental scheme was determined. This involved ①weighing 500 mg of vegetable samples and adding 20 mL of methanol-Mcllvaine-Na EDTA solution; ② conducting ultrasonic and centrifugal extraction three times; ③ Allowing rotary evaporation to 20 mL to pass a HLB solid phase extraction column; ④ Eluting the extraction column using 6 mL of methanol, upon which the eluent was dried almost completely; ⑤ Re-dissolving the eluent with a mixed solution of acetonitrile:water (volume ratio of 2:8); ⑥ Detecting by UPLC-MS/MS after centrifugation and filtering. Phase A and B of UPLC-MS/MS used an aqueous solution of 1‰ formic acid and acetonitrile, respectively to conduct gradient elution. Results showed that when the pakchoi spiked at 300 ng·g, the spiked recoveries of 13 antibiotics were 38.05%-96.97%. At 150 ng·g, the spiked recoveries were 34.52%-111.10%. At 50 ng·g, the recoveries of standard addition were 41.75%-107.13%, and the relative deviation (RSD) values were all below 8.68%. The detection limit was 0.4-1 ng·g, and the limit of quantification was 1.5-3 ng·g. This demonstrated good extraction and recovery efficiency on different types of leafy vegetables, and presented a good analytical application effect. The antibiotic residues were detected in four kinds of leafy vegetables in found in markets. The total content ranged from 1.59 ng·g to 32.01 ng·g, and the antibiotic content in samples was calculated by dry weight. The content of antibiotics in pakchoi was the highest, followed by Chinese cabbage, lettuce, and coriander. Among the antibiotics detected, sulfadimidine was the most abundant from the selected leafy vegetables. The content of antibiotics was very low, however the potential health risks caused by long-term consumption could not be ignored.
建立了一种分析方法，通过超高效液相色谱-三重四极杆质谱联用（UPLC-MS/MS）同时测定叶菜类蔬菜中磺胺类、喹诺酮类和大环内酯类的13种抗生素。在优化蔬菜基质中抗生素的提取溶液、净化方法和洗脱剂后，考虑环境变化和实验条件对结果的影响，确定了最佳实验方案。具体如下：①称取500mg蔬菜样品，加入20mL甲醇-Mcllvaine-Na EDTA溶液；②进行三次超声和离心提取；③旋转蒸发至20mL后通过HLB固相萃取柱；④用6mL甲醇洗脱萃取柱，洗脱液几乎完全干燥；⑤用乙腈:水（体积比2:8）混合溶液重新溶解洗脱液；⑥离心和过滤后用UPLC-MS/MS检测。UPLC-MS/MS的A相和B相分别使用1‰甲酸水溶液和乙腈进行梯度洗脱。结果表明，小白菜在300ng·g加标时，13种抗生素的加标回收率为38.05%-96.97%。在150ng·g时，加标回收率为34.52%-111.10%。在50ng·g时，标准加入回收率为41.75%-107.13%，相对偏差（RSD）值均低于8.68%。检测限为0.4-1ng·g，定量限为1.5-3ng·g。这表明该方法对不同类型叶菜类蔬菜具有良好的提取和回收效率，并呈现出良好分析应用效果。在市售的四种叶菜类蔬菜中检测到了抗生素残留。总含量范围为1.59ng·g至32.01ng·g，样品中抗生素含量以干重计算。小白菜中抗生素含量最高，其次是大白菜、生菜和香菜。在所检测的抗生素中，磺胺二甲嘧啶在所选叶菜类蔬菜中含量最高。虽然抗生素含量很低，但长期食用所带来的潜在健康风险不容忽视。
