聚合物整体柱微萃取/超高效液相色谱法测定蜂蜜中的4种磺胺类药物

Determination of Four Sulfonamides in Honey by Ultra-high Performance Liquid Chromatography with Polymer Monolithic Column Microextraction

以4-乙烯基苯甲酸(VBA)和4-乙烯基苯硼酸(VPBA)为混合功能单体,与二乙烯基苯(DVB)共聚制备了poly(VBA-DVB-VPBA)整体柱,用于蜂蜜中磺胺类药物的提取。该柱的官能团丰富、均匀多孔、通透性和稳定性良好,可与磺胺类药物产生多种作用形式。通过对萃取条件(包括溶液pH值、上样体积、离子强度和洗脱体积)的优化,建立了聚合物整体柱微萃取与超高效液相色谱联用(PMME/UPLC)的分析方法,对实际样品中磺胺嘧啶、磺胺二甲基嘧啶、磺胺吡啶和磺胺噻唑进行了萃取分离。在最佳实验条件下,4种目标物在相应质量浓度范围内线性关系良好,相关系数(r^(2))均大于0.99;该整体柱的富集因子为10.97~12.82,萃取率为73.1%~85.5%;所建分析方法的检出限为8.32~16.2 ng/mL,定量下限为27.5~53.9 ng/mL;实际样品的加标回收率为89.8%~105%,相对标准偏差(RSD)为2.0%~7.2%。该方法试剂用量少、耗时短且操作简便,能够满足食品中低浓度抗生素的实际监测需要。

In this paper,an analytical method of ultra-high performance liquid chromatography with a polymer monolithic column microextraction(PMME/UPLC)was established for the extraction and separation of sulfadiazine(SDZ), sulfamethazine(SMZ), sulfapyridine(SPD)and sulfathiazole(STZ)in honey.The polymer monolithic column was prepared by the thermally initiated in-situ polymerization in pretreated glass capillaries,using 4-vinylbenzoic acid(VBA)and 4-vinylphenylboric acid(VPBA)as mixed functional monomers, methanol and toluene as the porogenic solvent and azobisisobutyronitrile(AIBN)as the initiator to copolymerize with divinylbenzene(DVB).The poly(VBA-DVB-VPBA)monolithic column was used to extract sulfonamides(SAs)in honey in micro-extraction,and the target components were separated on a ZORBAX Eclipse Plus C18 column(2.1 mm × 50 mm i.d.,1.8 μm),then detected by diode array detection(DAD).The extraction performance of the monolithic column was evaluated by peak area of chromatography.The properties of the monolithic column were characterized by infrared spectroscopy(IR),scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDX).With rich functional groups,uniform porosity,good permeability and stability,the column could adsorb sulfonamides by ion exchange,hydrophobic interaction,hydrogen bonding and B-N coordination,etc.The extraction conditions were optimized as follows:sample volume:3 mL,pH value:4,NaCl concentration:60 g/L,and elution volume:200 μL.The method was used for the extraction and separation of SDZ,SMZ,SPD and STZ in the actual samples.Under the optimized conditions, there were good linear relationships for the four target substances in corresponding mass concentration ranges,i.e.40-200 ng/mL for SDZ,and 60-200 ng/mL for SPD,SMZ and STZ,with their correlation coefficients(r^(2))higher than 0.99.The enrichment factor of the monolithic column was between 10.97 and 12.82,while its extraction rate for four SAs ranged from 73.1%to 85.5%.The limits of detection and the limits of quantitation were in the ranges of 8.32-16.2 ng/mL and27.5-53.9 ng/mL,respectively.The method was applied to the analysis of four SAs drugs in honey,and no target was detected in the actual samples.The average recoveries for those compounds at two spiked levels of 60.0 ng/mL and 100 ng/mL ranged from 89.8%to 105%,with relative standard deviations(RSD)of 2.0%-7.2%.With the advantages of low reagent consumption,short time and simple operation,the method could meet the requirements for extraction and separation of SAs in honey,and provide a simple and reliable approach for the actual monitoring of low-concentration antibiotics in food.