Rapid method for the determination of multiple pyrethroid residues in fruits and vegetables by capillary column gas chromatography.
A rapid and economical simplified multi-residue method is described for the determination of multiple pyrethroid insecticides in fruits and vegetables. The residues are extracted from crops with methanol and the crop co-extractives are removed by toluene partitioning and Florisil-charcoal minicolumn chromatography. The final extract is analysed by capillary column gas chromatography with electron-capture detection. The recoveries were determined by fortifying six different crops (apples, oranges, cabbages, pears, peppers and tomatoes) with eleven pyrethroids (Py-115, allethrin, biphenthrin, fenpropathrin, cyhalothrin, permethrin, cyfluthrin, flucythrinate, fluvalinate, fenvalerate and deltamethrin) at three levels, 0.01-0.07, 0.10-0.70 and 1.0-7.0 mg/kg. Three determinations were made at each level for each crop. Recoveries of the eleven pyrethroids ranged from 70.4 to 110.0% at the three different levels. The practical determination limit of the method was in the range 3.0-30.0 micrograms/kg for all the pyrethroid insecticides. The proposed method had major advantages that simplified steps were achieved for the extraction and the clean-up, the solvent consumption was reduced and the analysis time was shortened.
Qin Huangdao Import and Export Commodity Inspection Bureau, Hebei, China.
G F
GF
Pang
C L
CL
Fan
Y Z
YZ
Chao
T S
TS
Zhao
D002849:Chromatography, Gas; D002852:Chromatography, Ion Exchange; D004563:Electrochemistry; D005638:Fruit / Q000737:chemistry*; D007202:Indicators and Reagents; D010573:Pesticide Residues / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis*; D014675:Vegetables / Q000737:chemistry*
D007202:Indicators and Reagents; D010573:Pesticide Residues; D011722:Pyrethrins