RESUMO
A headspace-solid phase microextraction-gas chromatography-mass spectrometric (HS-SPME-GC-MS, hereafter abbreviated as "SPME") method was developed for dedicated organophosphorus (OP) pesticides assessment in multiple vegetable and fruit commodities. Specific extraction variables were optimised to achieve harmonised extraction performance of eleven OPs in a great span of seven characteristic commodities cataloged in Codex Alimentarius Commission. Comprehensive validation study confirmed analytical robustness of the SPME treatment in turnip, green cabbage, French beans, eggplant, apple, nectarine and grapes. Based on range-specific evaluation, extraction of individual OPs was characterised by sub-ppb level sensitivity and a wide 0.01-2.5 mg L(-1) dynamic range. Effective sample clean-up afforded precise quantification (0.5-10.9% R.S.D.) within a 70-120% recovery range at the MRL levels specified for individual commodities. Compared to conventional methods currently used, the SPME treatment developed here is quick, accurate, and relatively environmental friendly; it represents an attractive, practical way to deliver international standards in OP screening routines.
