Development and validation of a method for the analysis of total amitraz in fruit and honey with quantification by gas chromatography-mass spectrometry

Marianne Caldow (1) , Richard John Fussell (2) , Frankie Smith (3) , Matthew Sharman (3)

1 Central Science Laboratory
2 Pesticides
3 Central Science Laboratory

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 GC-MS. 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's 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.

Mots clés: Life Sciences

Marianne Caldow, Richard John Fussell, Frankie Smith, Matthew Sharman. Development and validation of a method for the analysis of total amitraz in fruit and honey with quantification by gas chromatography-mass spectrometry. Food Additives and Contaminants, 2007, 24 (03), pp.280-284. ⟨10.1080/02652030601013638⟩. ⟨hal-00577516⟩