Investigation of Arsenic and Cadmium Contents in Rice Samples in Turkey by Electrothermal Atomic Absorption Spectrometry

Electrothermal atomic absorption spectrometry was the method used for the direct determination of arsenic and cadmium traces in rice samples. The optimum experimental conditions were investigated in the presence of a Pd/Mg(NO₃)₂ modifier. For arsenic and cadmium, the detection limits were 6.1 and 0.7 μg?kg^?1, whereas the characteristic concentrations were 1.33 and 0.067 μg?L^?1, respectively. For the validation of the method, the concentrations of As and Cd in IRMM-804 rice flour and GBW-08503 wheat flour certified reference materials were determined after microwave-assisted digestion of the samples. The results were found within the uncertainty limits of the certified values. The different 25 rice samples sold in Turkey were digested using a microwave system and then analyzed. The average (range) As and Cd concentrations of all samples were 0.0985 (0.0204–0.1708) and 0.0314 (0.0084–0.0775) mg?kg^?1, respectively. The arsenic and cadmium results were at acceptable levels. The average As and Cd amounts taken from rice are below the provisional tolerable weekly intake levels accepted by the World Health Organization. The distribution of analyte concentrations in some selected rice packages was investigated. The concentrations of both analytes were changed in a wide range even in the same packages.