Key Lab of Agro-product Quality and Safety, Institute of Quality Standards and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China.
J Agric Food Chem. 2012 Jan 11;60(1):60-5. doi: 10.1021/jf204183d. Epub 2011 Dec 28.
An effective method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and optimized to obtain a complete separation of five representative plant growth regulators (PGRs) [gibberellic acid, 2,4-dichlorophenoxyacetic acid (2,4-D), thidiazuron, forchlorfenuron, and paclobutrazol] in fruits. Extraction was performed with acetonitrile containing 0.1% (v/v) acetic acid, applying modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) methodology. LC-MS/MS conditions including composition of mobile phases and mass spectrometry (MS) conditions were evaluated to achieve the highest sensitivity in MS detection. All of the data acquisition was employed in the segmented multiple-reaction monitoring mode for the selected negative and positive transition ions. The octadecylsilyl (C18) dispersive solid-phase extraction (SPE) sorbent was found to provide the more satisfied recoveries than primary secondary amine (PSA) and graphitized carbon black (GCB) for five target PGRs. The optimized method allowed for recoveries of 76-112% for the five PGRs from fruit samples with relative standard deviation (RSD) values less than 10%. Limits of quantification (0.5-16.5 μg/kg) were lower than the maximum limit of residues established for PGRs. The results demonstrated that the developed LC-MS/MS and QuEChERS extraction method is highly effective for analyzing trace amounts of target PGRs in fruit samples. Finally, the method was successfully used to detect residual PGRs in Beijing, China, in 2010. The concentrations of 2,4-D (5.1-1503 μg/kg) and paclobutrazol (1-1381 μg/kg) found in orange and peach, respectively, suggesting that the use of these PGRs in these fruits should be regulated in China in the future.
建立并优化了一种采用液相色谱-串联质谱法（LC-MS/MS）的有效方法，以实现水果中五种代表性植物生长调节剂（PGRs）[赤霉素、2,4-二氯苯氧乙酸（2,4-D）、噻二唑隆、氯吡脲和多效唑]的完全分离。采用含 0.1%（v/v）乙酸的乙腈进行提取，应用改良的快速、简便、廉价、有效、耐用和安全（QuEChERS）方法。对 LC-MS/MS 条件（包括流动相组成和质谱（MS）条件）进行了评估，以实现 MS 检测的最高灵敏度。所有数据采集均采用选择的负离子和正离子分段多反应监测模式。结果发现，十八烷基硅烷（C18）分散固相萃取（SPE）吸附剂对五种目标 PGR 的回收率优于正相二次胺（PSA）和石墨化炭黑（GCB）。该优化方法可使五种 PGR 从水果样品中的回收率达到 76-112%，相对标准偏差（RSD）值小于 10%。定量限（0.5-16.5 μg/kg）低于为 PGRs 设定的最大残留限量。结果表明，开发的 LC-MS/MS 和 QuEChERS 提取方法对水果样品中痕量目标 PGRs 的分析非常有效。最后，该方法成功用于 2010 年在中国北京检测残留 PGRs。在橙和桃中分别检测到 2,4-D（5.1-1503 μg/kg）和多效唑（1-1381 μg/kg）的浓度，这表明在中国未来应该对这些水果中使用这些 PGRs 进行监管。
