Determination of deltamethrin residues in plant materials by liquid chromatography/tandem mass spectrometry with electrospray ionization.
This paper describes a selective and sensitive method that uses liquid chromatography/tandem mass spectrometry with positive electrospray ionization (ESI+) for the determination of deltamethrin in a variety of crops. Samples were extracted by conventional high-speed blending. Some samples required no further cleanup; others were cleaned up by gel permeation chromatography, strong cation-exchange cartridges, or partitioning with n-hexane. In the determinative step, the buffered neutral mobile phase, consisting of 10 mM ammonium acetate (pH 6.8) and methanol, and ESI+ provided strong ammonium adduct formation to [M+NH4]+ at m/z 523, and the multiple-reaction monitoring (MRM) transition at m/z 523/281 was used for the quantitation of deltamethrin. A second MRM transition at m/z 525/283 was used for confirmation. The limit of quantitation (LOQ) values were 0.01 mg/kg for edible materials and 0.05 mg/kg for nonedible materials. Mean overall recoveries at the LOQ and the 10-fold LOQ ranged from 73 to 96%, and the relative standard deviations were <10% for all samples materials analyzed.
Zimmer
Dieter
D
Bayer CropScience AG, Alfred-Nobel-Str. 50, D-40789 Monheim, Germany. dieter.zimmer@bayercropscience.com
Philipowski
Christiane
C
Posner
Birgit
B
Gnielka
Agnes
A
Dirr
Edgar
E
Dorff
Mario
M
D002138:Calibration; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid / Q000379:methods*; D001467:Hordeum / Q000378:metabolism; D007306:Insecticides / Q000032:analysis; D008956:Models, Chemical; D009570:Nitriles / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis; D010944:Plants / Q000378:metabolism*; D011722:Pyrethrins / Q000032:analysis*; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000379:methods; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013696:Temperature; D014908:Triticum / Q000378:metabolism
D007306:Insecticides; D009570:Nitriles; D010573:Pesticide Residues; D011722:Pyrethrins; C017180:decamethrin