Tenth International Conference On Advances In Applied Science And Environmental Technology - ASET 2020
Author(s) : Mirza Naseer Ahmad, MITSUO YOSHIDA
As and Mn contaminated groundwater is widely supplied as agricultural and drinking water in District Chiniot, Punjab, Pakistan. In order to assess the impact of contaminated groundwater to agricultural products, trace elements were analyzed for samples of rice and wheat grains harvested from the field in Chiniot. Total concentrations of As and Mn were measured using an inductively coupled plasma mass spectrometer (ICP-MS) after a nitric acid extraction. Chemical speciation of As, including organic/inorganic As (III) and As (V), was also examined applying a combined method of a high performance liquid chromatography (HPLC) and ICPMS. The analytical results showed that the concentration of total As in rice and wheat grains ranges from 0.05 to 0.10 mg/kg, while that of total Mn from 3.1 to 38.9 mg/kg. The concentration of manganese is much higher in wheat than in rice. The chemical speciation of arsenic contained in rice and wheat grains shows that inorganic As (III) ranges from 0.03 to 0.06, inorganic As (V) from 0.01 to 0.02, and dimethylarsinic acid (DMA) from 0.02 to 0.05 mg/kg. Monomethylarsonic acid (MMA) was not detected in either rice or wheat grain. The contamination level of total As in rice grains is less than 0.2 mg/kg that is the recommended maximum limit by Codex, which means no immediate health risk.