title: [Determination of five diacylhydrazine insecticide residues in welsh onion using high performance liquid chromatography-tandem mass spectrometry].
abstract: A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) method was established for the determination of RH-5849, methoxyfenozide, chromafenozide, fufenozide and tebufenozide residues in Welsh onion. The residues in Welsh onion were extracted by blending with acetonitrile, concentrated after salting out and purified with a Florisil column. The mobile phase was a mixture of methanol and water (containing 0.1% formic acid) (60:40, v/v) at a flow rate of 0.2 mL/min. The mass spectrometry was operated with electrospray in positive ionization mode and five diacylhydrazine insecticides were identified in multiple reaction monitoring (MRM) mode. The fragmentation pathways for the main product ions were analyzed. No significant matrix effect was found when the five diacylhydrazines were detected after the samples were purified by Florisil columns. The calibration curves showed good linearity within the concentrations of 2-400 microg/L with the correlation coefficients more than 0.999. The recoveries of the five diacylhydrazines spiked in Welsh onion were 72.6%-95.5% at spiked levels of 0.002-0.2 mg/kg. The relative standard deviations (RSDs) were less than 15%. The limit of quantitation (LOQ) was 2 pg/kg for each diacylhydrazine. This method is sensitive and accurate in the determination of the five diacylhydrazine insecticides in Welsh onion.
authors.affiliation: Institute of Quality and Standard on Agricultural Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. qianmingrong@yahoo.com.cn
authors.forename: Mingrong
authors.initials: M
authors.lastname: Qian
authors.forename: Hu
authors.initials: H
authors.lastname: Zhang
authors.forename: Liqin
authors.initials: L
authors.lastname: Wu
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Wang