Determination of the pesticides diflubenzuron and clofentezine in plums, strawberries and blackcurrant-based fruit drinks by high performance liquid chromatographic/atmospheric pressure chemical ionization-mass spectrometry.
A high performance liquid chromatographic/atmospheric pressure chemical ionization-mass spectrometric (HPLC/APCI-MS) method has been developed for the determination of the pesticides diflubenzuron (1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea) and clofentezine (3,6-bis(2-chlorophenyl)-1,2,4,5-tetrazine) in plums, strawberries and blackcurrant-based fruit drinks. Samples were homogenized with acetone, extracted into dichloromethane + cyclohexane and cleaned-up by high performance gel permeation chromatography. HPLC was performed on an ODS column with methanol + water at 1 mL/min. Detection was by negative-ion selected-ion monitoring APCI-MS. Comparison of response with solvent and matrix-matched standards showed some enhancement of response for the latter, and these standards were consequently used for quantification. The calibration was linear over the range 0.05-0.50 ng/microL in all three matrices. The mean overall recovery of diflubenzuron and clofentezine from spiked extracts (0.086 mg/kg) in all three matrices was 76% and 70% respectively with relative standard deviations of 15% and 12% respectively (n = 12). The limit of detection was both compound and commodity dependent and ranged from 0.01-0.05 ng/microL, equivalent to 0.003-0.014 mg/kg in the crop.
Ministry of Agriculture, Fisheries and Food, CSL Food Science Laboratory, Coloney, Norwich, UK.
K A
KA
Barnes
R J
RJ
Fussell
J R
JR
Startin
S A
SA
Thorpe
S L
SL
Reynolds
D001487:Basidiomycota / Q000737:chemistry; D001628:Beverages / Q000032:analysis*; D002722:Chlorobenzenes / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D004132:Diflubenzuron / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D007306:Insecticides / Q000032:analysis*; D013058:Mass Spectrometry
D002722:Chlorobenzenes; D007306:Insecticides; D004132:Diflubenzuron; C062106:clofentezine