Regresar

Verification of the atomic absorption spectroscopy with graphite furnace analytical method for the quantification of cadmium in cocoa almonds (Theobroma cacao)

Abstract:

The flame atomic absorption (AA) spectroscopy method for the determination of cadmium (Cd) in cocoa almond (Theobroma cacao) used by Agrocalidad is toxic to humans and the environment, reason for which the atomic absorption spectroscopy method with graphite furnace (GFAAS) was used, because it is more reliable and safer. Thus, four performance parameters of GFAAS method were used to quantify Cd in cocoa almond, by using certified reference material (MRC) and samples from four farms (A,B,C,D) located in the most important cocoa area of Ecuador, Flavio Alfaro city, province of Manabi. An interlaboratory test was performed and finally a protocol (PEE/B/14) was developed. Using the MRC (Code 07806B and 07167) was verified: Linearity, precision, veracity and uncertainty in accordance with international standards, Eurachem Guide of Eurolab España et al. (2016), and with the standard IRAM 35050 (2001) were found linearity between 0 and 8 ppb with R2 = 0.9988; standard deviation 0.0005 and 0.0022, respectively; slant was 0.007 and the recovery percentage was 109.75; standard uncertainty was 0.00013 and 0.00082. The content of Cd in samples from farm A was 0.54 ppm, B and D farms 0.26 ppm and 0.15 ppm in farm C. In the interlaboratory test, the same concentration of Cd was established for simple C3 and, in accordance with the stipulated by the European Union, cocoa from the four farms could be exported without restrictions.