title: [Analysis of organochlorine pesticides and pyrethroid pesticides in vegetables by gas chromatography-electron capture detection coupled with solid-phase extraction using multiwalled carbon nanotubes as adsorbent].
abstract: A multi-residue analytical method based on solid-phase extraction (SPE) with multiwalled carbon nanotubes (MWCNTs) as adsorbent was developed. The determination of 6 organochlorine pesticides and 7 pyrethroid pesticides in vegetables (including cucumber, cherry tomato, cabbage, lettuce, purple cabbage, leek, shallot and onion) was carried out by gas chromatography-electron capture detection (GC-ECD). The GC-ECD method used two columns (HP-50 and HP-1) and two ECD detectors. The HP-50 column was used for the analysis and the HP-1 column for validation. The clean-up conditions were optimized. The analytes were extracted by acetonitrile, and the extract was cleaned up by the MWCNTs SPE cartridge. The extract was re-dissolved by hexane, eluted with acetone-hexane (7:3, v/v) from the columns. The recoveries were over 70% for the 11 pesticides in the 13 pesticides. The results indicated that the MWCNTs SPE cartridge was efficient for 8 vegetable samples, because it reduced the contamination of the coloring materials to GC-ECD. The experimental results showed the MWCNTs SPE cartridge can adsorb the coloring materials and the eluant was nearly colorless.
authors.affiliation: Department of Chemistry, Hebei North University, Zhangjiakou 075000, China.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Zhao
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Jia
authors.forename: Mingyu
authors.initials: M
authors.lastname: Ding
authors.forename: Dajiang
authors.initials: D
authors.lastname: Sun
authors.forename: Mengbin
authors.initials: M
authors.lastname: Zhao
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D007306:Insecticides / Q000032:analysis; D037742:Nanotubes, Carbon; D010573:Pesticide Residues / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods; D014675:Vegetables / Q000737:chemistry*
chemical_list: D006843:Hydrocarbons, Chlorinated; D007306:Insecticides; D037742:Nanotubes, Carbon; D010573:Pesticide Residues; D011722:Pyrethrins