加速溶剂萃取-固相萃取/超高效液相色谱-串联质谱法测定育苗基质中矮壮素与助状素

研究建立了一种加速溶剂萃取-固相萃取/超高效液相色谱-串联质谱法（SPE-UPLC-MS/MS）测定育苗基质中矮壮素和助状素的分析方法。样品采用快速溶剂萃取仪（ASE）提取，经CBA弱阳离子交换柱净化后，在亲水作用色谱柱上用SeQuant ZLC-HILIC MEKCK色谱柱进行分离；电喷雾正离子（ESI+）模式电离，多反应监测（MRM）模式检测。矮壮素和助状素的质量浓度在0.2~10 μg/kg范围内线性关系良好（r2>0999），在2、5、10 μg/kg加标水平的平均回收率分别为77%~106%和97%~111%，相对标准偏差（RSD）分别为7.3%~21.7%和5.6%~16.1%，检出限（LOD）均为0.02 μg/kg，定量下限（LOQ）均为0.1 μg/kg。该方法简便、快速、灵敏、准确，适合育苗基质中矮壮素和助状素残留的确证和定量测定。

Determination of Chlormequat and Mepiquat Residues in Seeding Cultivation Using Accelerated Solvent Extraction-Solid phase Extraction/Ultra-performance Liquid Chromatography-Tandem Mass Spectrometry

A method for the determination of chlormequat and mepiquat residues in samples from seeding cultivation products was established by accelerated solvent extraction-solid-phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The samples were extracted with ASE 200 system and cleaned up with weak cation exchange(CBA) column.The identifications of chlormequat and mepiquat were performed on a HILIC column packed with 5 μm particles under isocratic LC conditions by using 0.1% formic acid in 20 mmol/L ammonium acetate(A) and acetonitrile(B)(VA ∶ VB=40 ∶ 60).The quantification of analytes was achieved by using electrospray ionization under positive ion mode(ESI+) with multiple reaction monitoring(MRM).The result indicated that the calibration curves were linear in the range of 0.2-10 μg/kg for both compounds.The average recoveries at spiked concentration levels of 2,5,10 μg/kg ranged from 77% to 111% with relative standard deviations of 5.6%-21.7%.The limits of detection were 0.02 μg/kg and the limits of quantitation were 0.1 μg/kg for both compounds.The established method was simple,rapid,sensitive and specific,and was suitable for the identification and quantification of chlormequat and mepiquat residues in seeding cultivation.