Hidrocarbonetos policíclicos aromáticos em cacau: desenvolvimento e validação de método analítico e produção de material para ensaio de proficiência

Abstract

A method for the determination of eight polycyclic aromatic hydrocarbons (PAHs) in cocoa beans by gas chromatography coupled to mass spectrometry was optimized and validated. The linear range of the method and the linearity of the calibration curves prepared in the solvents and in the matrices were determined by studying the matrix effects. The accuracy of the method was evaluated under conditions of repeatability and partial reproducibility, as well as robustness. Selectivity and recovery were investigated in standard addition assays on white samples. Limits of detection, quantification, decision and method detection were determined. A test material for assaying the proficiency of PAHs in cocoa beans was produced from spiked samples. After tests of homogeneity and short-term stability of the reference material, a stability study was conducted after one month and four months of refrigerated storage. Lack of homogeneity was detected only for the compound dibenz[a,h]anthracene. In the case of short-term stability, the batch was considered stable by the t-test criteria for all analytes, however no analytes showed stability when assessed by the proficiency deviation criteria. Only the benzo[a]anthracene compound was stable for one month under refrigeration. The PAHs prepared material in cocoa beans could be used for the purpose of conducting a proficiency test, since it is transported and storaged under refrigeration.