高效液相色谱-化学发光法检测牛奶中磺胺类药物残留

摘要

以4种磺胺类药物(Sulfonamides, SAs), 即磺胺脒(Sulfaguanidine, SGD)、磺胺嘧啶(sulfadiazine, SDZ)、磺胺噻唑(sulfathiazole, STZ)和磺胺二甲嘧啶(Sulfamethazine,SMZ)为分析物,基于其在碱性介质中对Ag配合物-鲁米诺(Luminol)与Ni配合物鲁米诺两化学发光体系发光强度均具有抑制作用的性质,建立了高效液相色谱-化学发光法检测牛奶中4种磺胺类药物的方法.将化学发光体系作为高效液相色谱的新型检测器,并对两种化学发光体系的检测器性能进行了比较.4种磺胺药物经高效液相色谱分离后,分别与Ag-Luminol及Ni-Luminol化学发光体系作用.色谱条件为:反相C18分离柱(250 mm × 4.6 mm,5 μm);0.1%甲酸-甲醇为流动相(V/V);梯度洗脱;流速1 mL/min.化学发光条件:Ag、Ni-Luminol两体系中,Ag配合物浓度1.4×10.-4 mol/L(含0.12 mol/L NaOH);Ni配合物浓度1.5×10.-5 mol/L(含0.12 mol/L NaOH);Luminol浓度均为1.2×10.-7 mol/L;试剂流速均为1.0 mL/min.在最佳的分离检测条件下,Ag-Luminol体系检测4种磺胺类药物的检出限分别为0.15、0.96、1.10和1.50 μg/mL,加标回收率为81.0%~101.5%;Ni-Luminol体系检测SGD、SDZ、STZ 3种磺胺类药物的检出限分别为1.5、17.2和16.8 μg/mL,加标回收率为83.9%~110.8%.相比之下,Ag-Luminol体系作为高效液相色谱检测器更佳.应用本方法对牛奶中4种磺胺类药物残留量进行检测,结果令人满意.%Sulfonamides (SAs), such as sulfaguanidine (SGD), sulfadiazine (SDZ), sulfathiazole (STZ) and sulfamethazine (SMZ), can drastically inhibit the chemiluminescence (CL) intensities generated in both Ag-Luminol and Ni-Luminol systems.Based on these observations, a novel method of high performance liquid chromatography (HPLC) coupled with CL detection was established.Both the Ag-Luminol and Ni-Luminol CL systems were employed as detectors, and the performances of the two detecting systems were compared.After separated by HPLC, four SAs reacted with Ag-Luminol and Ni-Luminol CL system, respectively.Chromatographic conditions were as follows: reversed-phase C18 column (250 mm × 4.6 mm,5 μm), gradient elution, and 0.1% (V/V) formic acid-methanol as mobile phase with flow rate of 1 mL/min.CL conditions were as follows: [Ag]=1.4×10.-4 mol/L (in 0.12 mol/L NaOH);[Ni]=1.5×10.-5 mol/L (in 0.12 mol/L NaOH);[Luminol]=1.2×10.-7 mol/L;and flow rate=1.0 mL/min.Under the optimal conditions, the detection limits of Ag-Luminol CL system were 0.15, 0.96, 1.10, 1.50 μg/mL for SGD, SDZ, STZ, and SMZ, respectively, and the recovery were 81.0%-101.5%.Comparatively, the detection limits of Ni-Luminol CL system were 1.5, 17.2, 16.8 μg/mL for SGD, SDZ and STZ, and the recoveries was 83.9%-110.8%.The result showed that the Ag-Luminol CL system had a much better performance.The method was applied to the determination of the residues of the above four SAs in milk with satisfactory results.