Determination of Arsenic by Inductively Coupled Plasma Mass Spectrometry in Mung Bean Seedlings for use as a Bio-indicator of Arsenic Contamination

Abstract

Mung bean seedlings can be used as a bio-indicator of As contamination. Endogenous As concentrations in the bio-indicator were determined by ICP-MS. Matrix effects and polyatomic interferences originating from the plant matrix and their correction procedures were studied. Experiments were carried out with arsenate and arsenite additions of 0.5 up to 50 µM of As to the growth medium. The arsenate uptake increased with increasing arsenate concentrations in the growth medium, the highest accumulation occurred in the roots. Arsenite seemed to be far more toxic than arsenate (lethal dosage at <10 µM). Phosphate was shown to lower the toxic effects of arsenate but had no effect on the arsenite uptake. As an illustration, the endogenous arsenate concentration was correlated with the polyamine synthesis. It was shown that above 2.2 µg g ^-1 of As in the dry mass the seedlings were in a ‘stress’ situation.