Validación del método para determinar Cd mediante GFAAS en cacao (Theobroma cacao).

Abstract

This research describes the validation of the method to determine cadmium (Cd) in cocoa (Theobroma cacao) by Graphite Furnace Atomic Absorption Spectrometry (GFAAS), using the reading of triplicate samples from different sources (coast, east and organic cocoa). It was verified that the concentrations are 0.645, 0.504 and 0.392 mg / kg respectively. For the characterization, cocoa was used since it contains a lower concentration of metal. The values obtained do not exceed the maximum residual limit suggested by the European Union. Based on the European Union validation protocol and AOAC 999.11 guideline. For three days, two analysts prepared the samples, replicating the blanks and the fortified samples six times at low, medium and higher levels. The instrument used was the Perkin Elmer 800 atomic absorption equipment coupled to a graphite furnace. For the statistical analysis, ANOVA, fisher, homogeneity of variances and uncertainty calculations were used. The proposed validation objectives were met in the following requirements, selectivity, linearity-response function, limits of detection and quantification, precision (repeatability and reproducibility) with the coefficient of variation <10%, accuracy (recovery) ranging between 80 and 120% at all levels. The uncertainty obtained is less than 33% at the lowest level with confidence interval (K = 2). It is concluded that the method is valid in all the critical parameters mentioned above. It is recommended to use lamps with sufficient energy (> 50%) and adjustments to the calibration curves.