Determinação de resíduos de agrotóxicos em mel de abelhas (Apis sp.) por cromatografia gasosa acoplada à espectrometria de massas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Among the problems concerning the quality of honey, are the physical and chemical characteristics, the identification of the floral and geographical origin, the occurrence of adulteration and contamination, especially with antibiotics and pesticides. The adequacy of these features to existing laws in the country makes the product more competitive for the export market. This work aims the development of a multi residue methodology for the determination of pesticides in honey, as a contribution to the improvement of methodologies for the analysis of contaminants described in Normative Instruction No 9, March 30, 2007 to MAPA and its application in samples of honey from different regions of Brazil. The technique used was gas chromatography coupled to mass spectrometry, using SIM acquisition mode, electron ionization (EI) at 70 eV. Three techniques of extraction - liquid-liquid extraction, solid phase extraction (C18) and dispersive solid phase extraction modified "QuEChERS" was evaluated. The results of the extraction procedures indicated the interference of the matrix in the chromatographic responses when compared with the analytical curve obtained only in ethyl acetate. Best analyte responses were obtained for the liquid-liquid extraction with ethyl acetate. A method using liquid-liquid extraction and analytical curves obtained in the matrix extract resuspended in ethyl acetate was developed and validated for the 20 pesticides from the classes of organochlorine pesticides, organophosphates, carbamates and pyrethroids. In this work the following parameters were assessed for validation of the method. Linearity of analytical curves (7 concentration levels and six injections each). Analytical curves were obtained to adjustment for quadratic regression and determination coefficients higher than 0.989. Limit of detection (LOD) calculated ranged from 0,4 to 13,4 ng mL-1 and limit of quantification (LOQ) performed between 1,4 and 60,8 ng mL-1. The precision for the study of repetibilibidade (% RSD between 3,4 and 32,9%) and accuracy (recovery rate - 92% a 115%). The fortifications of the samples were taken at three concentration levels (1,0 ìg kg-1, 5,0 ìg kg-1, 10,0 ìg kg-1). The methodology was applied to the analysis of 46 honey samples from different regions of Brazil. It was detected the presence of pesticides in 8 samples. In three of them, the compounds found may be related to the use of pesticides on crops in the neighborhood of apiaries

ASSUNTO(S)

mel analise teses alimentos contaminação teses 4 análise cromatográfica teses agrotóxicos teses

ACESSO AO ARTIGO

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