title: Simultaneous determination of pyrethrins residues in teas by ultra-performance liquid chromatography/tandem mass spectrometry.
abstract: A sensitive and effective method for the simultaneous quantitative determination of pyrethrin residues in teas was developed and validated using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The six major constituents of the pyrethrins (pyrethrin I and II, jasmolin I and II, and cinerin I and II) were successfully separated and independently confirmed in a single run within approximately 5 min. The multi-residue analysis of pyrethrins in teas involved simply extraction with acetonitrile, clean-up using a multilayer solid phase extraction cartridge, and subsequent separation by a hydrophilic end-capped Aquasil C18 columns with detection by tandem mass spectrometry using an electrospray ionization source in positive mode (ESI+). Recovery studies were carried out at three spiked levels (0.05, 0.1, 0.5 mg kg(-1)). The overall average recoveries using this method in green teas and black teas at the three concentration levels ranged from 76.15% to 101.86% with relative standard deviations (RSDs) in the range of 2.71-12.93% (n=5) for all analytes. The limits of detections (LODs) were below 0.009 mg kg(-1), which were lower than the maximum residue limits (MRLs) of 0.5 mg kg(-1) in tea samples established by the European Union legislations in 2008, while the limits of quantification (LOQ) did not exceed 0.03 mg kg(-1). This study provides a theoretical basis for China to draw up MRLs for pyrethrins in teas.
authors.affiliation: Key Laboratory of Pesticide Chemistry and Application, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Caihong
authors.initials: C
authors.lastname: Lu
authors.forename: Xingang
authors.initials: X
authors.lastname: Liu
authors.forename: Fengshou
authors.initials: F
authors.lastname: Dong
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Wencheng
authors.initials: W
authors.lastname: Song
authors.forename: Changpeng
authors.initials: C
authors.lastname: Zhang
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Li
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000032:analysis / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007306:Insecticides / Q000032:analysis* / Q000302:isolation & purification; D011722:Pyrethrins / Q000032:analysis* / Q000302:isolation & purification; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013662:Tea / Q000737:chemistry*
chemical_list: D001643:Bridged Bicyclo Compounds; D007306:Insecticides; D011722:Pyrethrins; D013662:Tea; C550759:cinerin A; C550760:cinerin B; C009119:pyrethrin I