提出了同时测定柑橘中多菌灵、2,4-滴、咪鲜胺、抑霉唑、噻菌灵、嘧霉胺、甲基硫菌灵等7种保鲜剂残留量的QuEChERS-超高效液相色谱-电喷雾串联四极杆质谱法。用5%(φ)甲酸-乙腈溶液提取样品中的保鲜剂后加入盐析剂分层,上清液放入盛有无水硫酸镁、N-丙基乙二胺吸附剂(PSA)、C18吸附剂的净化管中净化,采用Hypersil Gold C18色谱柱,以不同比例的0.15%(φ)甲酸溶液和乙腈组成的混合液为流动相进行梯度洗脱。以电喷雾离子源正负离子切换多反应监测(MRM)模式进行质谱分析。7种保鲜剂的线性范围均在2.00~100 μg·L-1之间,测定下限(10S/N)为0.02~1.2 μg·kg-1。1.00,5.00,40.0 μg·kg-1等3个添加水平的回收率在80.5%~120%之间,相对标准偏差(n=8)在2.8%~9.7%之间。

QuEChERS-UHPLC-MS/MS was proposed for the determination of carbendazim, 2,4-dichlorophenoxyacetic acid, prochloraz, imazalil, thiabendazole, pyrimethanil, thiophanate methyl residues in citrus. The preservatives in the samples were extracted with a mixture solution of 5% (φ) formic acid and acetonitrile, stratified by a salting-out agent. The supernatant was cleaned up with purification pipe filled with MgSO4, C18 and PSA. Hypersil Gold C18 column was used as stationary phase, and mixtures of acetonitrile and 0.15% (φ) formic acid solution in various ratios were used as mobile phase in gradient elution, then determinated by UHPLC-MS/MS. ESI and MRM were adopted in MS operated in the positive and negative ion switch mode. Linearity ranges of the 7 preservatives were found to be same between 2.00-100 μg·L-1, with lower limits of determination (10S/N) in the range of 0.02-1.2 μg·kg-1. Recovery rates at the three concentrations of 1.00, 5.00, 40.0 μg·kg-1 ranged from 80.5% to 120% with RSDs (n=8) in the range of 2.8%-9.7%.