title: Application of dual counter-current chromatography for rapid sample preparation of N-methylcarbamate pesticides in vegetable oil and citrus fruit.
abstract: Dual counter-current chromatography (dual CCC) has been successfully applied to rapid sample preparation for the simultaneous determination of residual carbaryl, fenobucarb and methomyl in vegetable oil and citrus fruit. The citrus fruit samples were extracted with n-hexane solution containing stable isotopically labeled internal standards (methomyl-d3, fenobucarb-d3 and carbaryl-d9), and applied to dual CCC using a two-phase solvent system of n-hexane-acetonitrile to purify the carbamate pesticides from aliphatic sample matrix. The coiled column was rotated at 420 rpm, the lower mobile phase was introduced through the head toward the tail, and the upper mobile phase in the opposite direction. Due to the high partition efficiency of dual CCC, the lower phase fraction collected from 2 to 5 min after injection could be subjected to flow-injection tandem mass spectrometry directly after concentration. Repetitive sample injection can be performed at high reproducibility without a risk of contamination from the compounds retained in the column.
authors.affiliation: Aichi Prefectural Institute of Public Health, Kita-ku, Nagoya 462-8576, Japan. yuuko_1_itou@pref.aichi.lg.jp
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ito
authors.forename: Tomomi
authors.initials: T
authors.lastname: Goto
authors.forename: Sadaji
authors.initials: S
authors.lastname: Yamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Hisao
authors.initials: H
authors.lastname: Oka
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakazawa
authors.forename: Hisamitsu
authors.initials: H
authors.lastname: Nagase
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito
mesh_terms: D002219:Carbamates / Q000302:isolation & purification*; D012721:Carbaryl / Q000302:isolation & purification; D002957:Citrus / Q000737:chemistry*; D003377:Countercurrent Distribution / Q000379:methods*; D008724:Methomyl / Q000302:isolation & purification; D010575:Pesticides / Q000302:isolation & purification*; D010938:Plant Oils / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D002219:Carbamates; D010575:Pesticides; D010938:Plant Oils; D008724:Methomyl; C019276:BPMC; D012721:Carbaryl