title: Evaluation of microwave-assisted extraction for the analysis of organophosphorus and pyrethroid pesticides in green onions.
abstract: The aim of this study was to evaluate the efficiency of microwave-assisted extraction (MAE) for the analysis of organophosphorus (OP) and pyrethroid (PYR) pesticides in green onions by GC/MS. We optimized MAE extraction solvent, temperature, and time by using a certified reference material. As a result, the concentrations of two OP and two PYR target pesticides obtained by MAE with acetonitrile at 110 degrees C for 10 min were in good agreement with certified concentrations and comparable to the results by homogenization used as reference extraction technique. When the recovery test, performed by spiking the target pesticides into blank samples (5.0 g), was carried out with our optimized MAE conditions, mean recoveries of 16 OP and 10 PYR pesticides were 72-108% for a 1.0 pg spiking level and 70-119% for a 0.2 microg level. These results were acceptable according to the validation guideline for testing method of agricultural chemicals in food by Ministry of Health, Labour, and Welfare in Japan. The results suggested that MAE can be used for the analysis of OP and PYR pesticides in green onions.
authors.affiliation: National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba, Ibaraki 305-8563, Japan. t-ootake@aist.go.jp
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Otake
authors.forename: Youko
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Aoyagi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yarita
mesh_terms: D002138:Calibration; D003976:Diazinon / Q000032:analysis; D005278:Fenitrothion / Q000032:analysis; D005504:Food Analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007202:Indicators and Reagents; D007553:Isotope Labeling; D057230:Limit of Detection; D008872:Microwaves; D019697:Onions / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000302:isolation & purification; D026023:Permethrin / Q000032:analysis; D010575:Pesticides / Q000032:analysis* / Q000302:isolation & purification; D011722:Pyrethrins / Q000032:analysis* / Q000302:isolation & purification; D012015:Reference Standards; D052616:Solid Phase Extraction; D012997:Solvents
chemical_list: D007202:Indicators and Reagents; D009943:Organophosphorus Compounds; D010575:Pesticides; D011722:Pyrethrins; D012997:Solvents; C017160:cypermethrin; D026023:Permethrin; D005278:Fenitrothion; D003976:Diazinon