Development and validation of an analytical method for total amitraz in fruit and honey with quantification by gas chromatography-mass spectrometry.
The EU maximum residue limit (MRL) definition for amitraz is 'the sum of amitraz plus all its metabolites containing the 2,4-aniline moiety, expressed as amitraz'. A rapid and sensitive method has been developed and validated in-house for the determination of total amitraz in pears, strawberries, oranges and honey. Samples were hydrolysed (under acidic followed by alkaline conditions) to convert amitraz to 2,4-dimethyaniline, which was then partitioned into 2,2,4-trimethylpentane prior to quantification by gas chromatography-mass spectrometry. The method was validated at 0.02 and 0.1 mg kg(-1) amitraz (well below MRL requirements) with a lowest calibrated level (LCL) for 2,4-dimethylaniline of 0.002 mg kg(-1) (equivalent to 0.0024 mg kg(-1) amitraz). A single partition step yielded recoveries of approximately 60% (with % CV values in the range 3.3-8.2), which is satisfactory for screening purposes. A second partition increased recoveries by 10-20%, making the method suitable for the quantification of residues.
Caldow
Marianne
M
Central Science Laboratory, Sand Hutton, York YO41 1LZ, UK. m.caldow@csl.gov.uk
Fussell
Richard J
RJ
Smith
Frankie
F
Sharman
Matthew
M
D005504:Food Analysis / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006722:Honey / Q000032:analysis*; D006801:Humans; D006868:Hydrolysis; D007306:Insecticides / Q000032:analysis / Q000302:isolation & purification; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification; D015203:Reproducibility of Results; D014052:Toluidines / Q000032:analysis* / Q000302:isolation & purification
D007306:Insecticides; D010573:Pesticide Residues; D014052:Toluidines; C014983:amitraz