Study and determination of As, Cr and Pb in amaranth seeds

Abstract

The concentration of As, Cr and Pb toxic elements was determined in three species of amaranth seeds: A. hypochondriacus, A. cruentus and A. dubius. The determinations were carried out by inductively coupled plasma optic atomic spectroscopy (ICP-OES). The result shows that Cr and As were found in minor concentrations than allowed by the World Health Organization (WHO; 120 and 4 mg kg-1 respectively); As (mg kg-1): A. dubius (0.76) A. cruentus (<0.50) and A. hypochondriacus (< 0.50); Cr (mg kg-1): A. dubius (9.79) A. cruentus (1.55) and A. hypochondriacus (1.52). However, the concentration of Pb was high (A. dubius (19.04) A. cruentus (30.20) and A. hypochondriacus (35.56) more than the maximum of WHO (10 mg kg-1). To avoid systematic error, recovery and validation studies were performed: recovery test: 102.3%; validation (by standard addition): 96.0 ? 103.1%. Due to the fact that amaranth had been proposed as new food due to its nutraceutical properties, the high concentration of Pb found in this study indicates that Pb should be evaluated in these amaranth species to avoid the intake of toxic element by human beings.