Simultaneous determination of 109 pesticides in unpolished rice by a combination of gel permeation chromatography and Florisil column purification, and gas chromatography/mass spectrometry.
A multi-residue method is described for the simultaneous analysis of 109 pesticides with different properties in unpolished rice. The range covers organophosphorus, organochlorine, carbamate, and synthetic pyrethroid pesticides. The pesticides were extracted from the sample using ethyl acetate. Most higher molecular weight components such as lipids in the co-extractives were removed by gel permeation chromatography (GPC) with a Bio-bead SX-3 column. A Florisil column with ethyl acetate/hexane as the eluting solvents was used for further cleanup. The pesticides were finally simultaneously determined by gas chromatography/mass spectrometry (GC/MS) in selective ion monitoring (SIM) mode. The average recoveries for most pesticides (spiked level 0.02, 0.1 and 1 microg/g) ranged from 70% to 110%, the relative standard deviation (RSD) was below 20% in every case, and the limit of detection (LOD) varied from 1 to 20 ng/g.
Zhang
Wei-Guo
WG
College of Science, China Agricultural University, Beijing 100094, PR China.
Chu
Xiao-Gang
XG
Cai
Hui-Xia
HX
An
Juan
J
Li
Chong-Jiu
CJ
D002850:Chromatography, Gel / Q000295:instrumentation; D005504:Food Analysis; D008401:Gas Chromatography-Mass Spectrometry; D017633:Magnesium Silicates / Q000737:chemistry*; D012275:Oryza / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*
D017633:Magnesium Silicates; D010573:Pesticide Residues; C005013:Florisil