超高效液相色谱-串联质谱法测定番茄(酱)及香梨中矮壮素和缩节胺残留量

建立了快速测定番茄（酱）及香梨中矮壮素和缩节胺残留量的超高效液相色谱-串联质谱（UPLC-MS/MS）方法。样品经V（水）:V（乙腈）=1:1提取，无需富集浓缩等特殊净化步骤，以Waters Acquity BEH HILIC色谱柱分离，电喷雾电离（ESI+），多反应监测（MRM）模式检测，基质匹配标准溶液峰面积外标法定量。结果表明:在0.001~0.02 mg/L范围内，矮壮素和缩节胺的质量浓度与对应的峰面积间线性关系良好，相关系数均大于0.999。矮壮素及缩节胺在番茄、香梨及番茄酱中的检出限（LOD）分别为0.000 4~0.002 mg/kg和0.000 9~0.002 mg/kg，定量限（LOQ）均为0.01 mg/kg。在0.01、0.02和0.05 mg/kg 3个添加水平下，矮壮素及缩节胺的回收率分别为71%~94%和75%~101%，相对标准偏差分别为1.9%~7.7%和2.8%~6.9%。该方法简便快捷，定量准确，可用于同时检测番茄（酱）及香梨中矮壮素和缩节胺的残留量。

Analysis of chlormequat chloride and mepiquat chloride residues in tomato, tomato paste and pear by using liquid chromatography-tandem mass spectrometry

A rapid method for analyzing the two plant growth regulators chlormequat chloride and mepiquat chloride residues in tomato, tomato paste and pear by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. The samples were extracted with V (water):V (acetonitrile)=1:1. Special clean-up procedures such as enrichment or concentration were not necessary. The chromatographic separation was carried out by HILIC column. Analytes were detected by electro-spray ionization (ESI⁺), and multiple reaction monitoring (MRM) mode. Quantification was performed by peak area external standard methods using matrix-matched calibration curves, which were linear in the range of 0.001-0.02 mg/L with good linear relationships. The correlation coefficients were all above 0.999. In the case of tomato, tomato paste and pear, the limits of detection (LOD) for chlormequat chloride and mepiquat chloride were estimated in the range of 0.0004-0.002, 0.0009-0.002 mg/kg, respectively. And the limits of quantification (LOQ) were both validated as 0.01 mg/kg. At 0.01, 0.02 and 0.05 mg/kg spiked levels, the recoveries and the relative standard deviations (RSD) was 71%-94%, 75%-101% and 1.9%-7.7%, 2.8%-6.9% for chlormequat chloride, and mepiquat chloride. Finally, this method was simple, quick, accurate, and could be applied to the determination of chlormequat chloride and mepiquat chloride residues in tomato, tomato paste and pear.