QuEChERS-超高效液相色谱-串联质谱法同时测定蔬果中34种植物生长调节剂的残留量

建立蔬菜水果中34种植物生长调节剂残留量的测定方法。样品经粉碎后,用Qu ECh ERS法进行前处理,5 g样品经10 m L乙腈溶液提取,4 g无水硫酸镁+1 g氯化钠+1g柠檬酸钠+0.5 g三水合二柠檬酸氢二钠盐析脱水后,根据不同样品状态,取上清液用不同净化粉末进行净化;色谱条件以Waters Acquity HSS T3柱进行分离,乙腈-水作为流动相,梯度洗脱;质谱离子化为电喷雾正负离子切换模式,多反应监测模式分段扫描检测;基质匹配外标峰面积法定量。化合物在2～100μg/kg范围内呈良好线性关系,34种植物生长调节剂的检出限为2～10μg/kg,该方法前处理快速、灵敏、准确,满足目前国内外对植物生长调节剂残留限量的要求,可为常见蔬菜水果中植物生长调节剂的监管提供技术支撑。

Determination of 34 Plant Growth Regulator Residues in Vegetables and Fruits by QuEChERS-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A method for the determination of 34 plant growth regulators in vegetables and fruits was established. Samples were pretreated by the quick, easy, cheap, effective, rugged and safe (QuEChERS) method after being ground. Five grams of the samples were extracted with 10 mL of acetonitrile, and dehydrated with a mixture of 4 g of MgSO4, 1 g of NaCl, 1 g of Na3Cit, 0.5 g of 2Na2HCit·3H2O. The supernatant extract was purified with different sorbents according to the state of samples. The analytes were separated on a Waters Acquity HSS T3 column with acetonitrile-water as the mobile phase using gradient elution, detected by mass spectrometry using electrospray ionization with piecewise scanning in the multiple-reaction monitoring (MRM) mode and quantified by the matrix-matched external standard peak area method. The calibration curves were linear in the concentration range of 2–100 μg/kg. The limits of detection (LODs) of 34 plant growth regulators were 2–10 μg/kg. The method was rapid, sensitive and precise, and could meet the requirements for the determination of plant growth regulator residues thereby providing technical support for regulation of plant growth regulator residues in common vegetables and fruits.