Construcción de un modelo de superficies de respuesta para la estandarización y validación de un método analítico en la empresa COLCOCOA.

Abstract

In this work, we used Response Surface Methodology (RSM) for the standardization and validation of an analytical method for the determination and quantification of Cadmium (Cd) in cocoa beans (Theobroma cacao L), using acid digestion and Atomic Absorption Spectroscopy (AA). In the standardization, we carried out a Box- Behnken design, found that the optimal method, which allow a maximum extraction of cadmium in samples of cacao beans in a range of concentration from 0.01ppm to 1.6ppm, is an acid digestion of 80 °C during ten minutes using 642.7 mg of a sample, 7.8 mL of HNO3 and 7.6 mL of H2O2. The proposed method has a good repeatability, is exact and precise, and presents a limit of detection of 0.004ppm and a limit of quantification of 0.008ppm, also allowing for a recovery mean of 96.8% of analyte. On the other hand, this method has advantages which allows the anaysis of samples in the range established in new legislation that will be applied in 2019 and speed up the analysis process, making possible most analysis per day to cost less.