吴学进 刘春华 罗金辉 李春丽 马晨 乐渊 吴南村

摘要：【目的】建立同步測定荔枝中甲哌啶、矮壮素等10种植物生长调节剂（PGRs）残留的QuEChERS净化—超高效液相色谱—串联质谱法（UPLC-MS/MS），为荔枝中多种PGRs残留同步检测提供技术参考。【方法】荔枝样品以1%（v/v）乙酸—乙腈提取，经优化QuEChERS前处理后，净化后的样品提取液以Agilent InfinityLab Poroshell 120 EC-C18柱为分离色谱柱，甲醇—5 mmol/L乙酸铵水溶液（含0.1%甲酸，v/v）缓冲溶液为流动相梯度洗脱，以UPLC-MS/MS在选择反应监测模式下对甲哌啶等10种PGRs目标物残留进行测定。【结果】在5～100 μg/kg范围内，10种PGRs质量浓度与对应的峰面积呈良好线性，相关系数（r2）均>0.9950;检出限范围为0.03～0.60 μg/kg。在10、25和100 μg/kg 3个添加水平范围内，平均回收率在71.8%～109.2%，相对标准偏差（RSD）在0.6%～10.0%。用优化的QuEChERS净化-UPLC-MS/MS对40份荔枝样品进行检测，其中1份样品检出多效唑，1份样品检出芸苔素内酯，PGRs检出率为5.0%。【结论】建立的QuEChERS净化-UPLC-MS/MS简便、快速，具有良好的灵敏度、准确度和精密度，可用于同步测定甲哌啶等10种PGR在荔枝中的残留。

关键词： 荔枝;QuEChERS;植物生长调节剂（PGRs）;超高效液相色谱—串联质谱（UPLC-MS/MS）

中图分类号： S482.8                          文献标志码： A 文章编号：2095-1191（2020）10-2532-08

Simultaneous determination of ten plant growth regulators residues in litchi by QuEChERS clean up-ultra high perfor-mance liquid chromatography-tandem mass spectrometry

WU Xue-jin， LIU Chun-hua*， LUO Jin-hui， LI Chun-li， MA Chen， LE Yuan， WU Nan-cun

（Analysis and Testing Center， Chinese Academy of Tropical Agricultural Sciences/Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruits and Vegetables， Haikou  571101，China）

Abstract：【Objective】A method for simultaneous determination of ten plant growth regulators（PGRs） residues in litchi，such as meperidine，chlorpromazine and others，was developed by using ultra high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） in combination with QuEChERS methodology， to provide reference for simultaneous determination of multiple PGRs residue in litchi. 【Method】The litchi samples were extracted with acetonitrile containing 1%（v/v） acetic acid and purified by the optimized QuEChERS pretreatment method， then the purified sample extracting solutions were separated in Agilent InfinityLab Poroshell 120 EC-C18 column with methanol-5 mmol/L ammonium acetate solution（containing 0.1% formic acid，v/v） as mobile phase by gradient program，and analyzed by using UPLC-MS/MS in selective reaction monitoring（SRM） mode for mepiquat chloride and other nine PGRs residues in samples. 【Result】The mass concentrations of ten PGRs showed good linearity with the corresponding peak area in the range of 5-100 μg/kg，and the correlation coefficient（r2） was more than 0.9950. The limits of detection（LODs） ranged from 0.03 to 0.60 μg/kg. The average recoveries at three spiked levels of 10，25，100 ?g/kg for all target compounds in the samples were in the range of 71.8%-109.2%，with relative standard deviations（RSD） between 0.6% and 10.0%. The optimized UPLC-MS/MS in combination with QuEChERS methodology mention above was used to detect 40 litchi samples，paclobutrazol was detected in one sample and so was brassinolide ，the detection rate of PGRs was 5.0%. 【Conclusion】The QuEChERS purofied-UPLC-MS/MS method is simple，rapid with high sensitivity and good repeatability， accuracy and precision， which can be used for simultaneous determination of ten PGR residues above mentioned in litchi.

Key words： litchi; QuEChERS; plant growth regulators（PGRs）; ultra high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）

Foundation item： Major Project of National Agricultural Product Quality and Safety Risk Assessment（GJFP2019 013）;Basic Research Project of Chinese Academy of Tropical Agricultural Sciences（1630082020009，1630082017001，1630082020002）

0 引言

【研究意义】荔枝（Litchi chinensis Sonn）是无患子科（Sapindaceae）荔枝属（Litchi Sonn.）果树，在我国有2000多年的种植记载历史。荔枝果实口感鲜甜，营养丰富，深得大众青睐。荔枝作为大众果盘的重要水果，其鲜果的产品质量安全一直受到密切关注，但长期以来人们更多关注于荔枝中的农药残留（王运儒等，2018），却忽视了荔枝中植物生长调节剂（Plant growth regulators，PGRs）的残留。PGRs是化学合成与植物内源激素有相似生理作用的一类物质，能调节植物的生长发育和代谢过程，达到增产增效、改善品质等目的，在现代高效农业生产中得到广泛应用。尽……