采用十八烷基三氯硅烷(octadecyltrichlorosilane,OTS)与N-[3-(三甲氧基硅基)丙基]乙二胺(N-[3-(trimethoxysilyl)propyl]ethylenediamine,ATS)改性三聚氰胺海绵(melamine sponge,MeS)制备得到2 种新型弹性多孔硅烷化MeS(OTS@MeS和ATS@MeS)净化材料,将其用于改良QuEChERS(quick,easy,cheap,effective,rugged and safe)基质净化过程,通过溶液自发浸润和物理挤压过程即可快速、高效分离干扰基质,结合超高效液相色谱-串联质谱技术建立了同时测定猪肉中49种抗生素多残留的分析方法.样品用1.0%乙酸-乙腈溶液提取并用2.0 g Na2SO4和0.5 g NaCl盐析,离心后取1 mL上清液复配使用OTS@MeS与ATS@MeS净化,随后使用Agilent ZORBAX Eclipse Plus C18色谱柱,以甲醇溶液和含有0.1%甲酸、5mmol/L乙酸铵的甲醇-水溶液(5∶95,V/V)为流动相进行梯度洗脱,采用电喷雾电离源、正离子多反应监测模式进行定性定量分析.结果表明:49种抗生素的相关系数均大于0.999,基质效应为-13.5%~10.9%,检出限在0.1~10μg/kg之间,定量限在0.3~30.3μg/kg之间;利用该方法在低、中、高3个加标水平下进行回收率实验,回收率范围为65.0%~112.7%,日内和日间相对标准偏差分别为0.3%~11.8%和2.4%~18.4%.该方法样品前处理过程简单、快捷、灵敏度高、准确性好,可用于猪肉中49种抗生素多残留的高效快速检测.
Two new types of elastic porous silanized melamine sponges(MeS)were prepared by silylation reaction using octadecyltrichlorosilane(OTS)and N-[3-(trimethoxysilyl)propyl]ethylenediamine(ATS),which were respectively designated as OTS@MeS and ATS@MeS.The silanized sponges were used to develop a modified quick,easy,check,effective,rugged,and safe(QuEChERS)method that can quickly and efficiently separate interfering matrices from the extract through spontaneous solution infiltration and physical extrusion.In this study,an analytical method using the modified QuEChERS procedure combined with ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)was established for the simultaneous determination of 49 antibiotic residues in pork.Samples were extracted with 10 mL of acetonitrile containing 0.1%acetic acid,and then salted out with 2.0 g of Na2SO4 and 0.5 g of NaCl.After centrifugation,a 1 mL aliquot of the supernatant was cleaned up with a mixture of OTS@MeS and ATS@MeS.The chromatographic separation was conducted on an Agilent ZORBAX Eclipse Plus C18 column with gradient elution using a mobile phase comprised of methanol and aqueous solution(methanol/water,5∶95,V/V)containing 0.1%formic acid and 5 mmol/L ammonium acetate.The qualitative and quantitative detection were performed by multiple-reaction monitoring(MRM)using an electrospray ionization source in the positive ion mode.The results showed that the correlation coefficients for all analytes were greater than 0.999.The matrix effects(ME)were in the range of-13.5%-10.9%.The limits of detection(LOQ)and quantitation(LOQ)were 0.1-10.0 and 0.3-33.3 μg/kg,respectively.The recoveries at three spiked levels ranged from 65.0%to 112.7%,with intra-and interday relative standard deviations(RSDs)of 0.3%-11.8%and 2.4%-18.4%,respectively.The developed method was simple,rapid,highly sensitive and accurate,and could be used for the efficient and rapid determination of the 49 antibiotics residues in pork.