Determination of inorganic arsenic species by hydride generation–inductively coupled plasma optical emission spectrometry

Abstract

A hydride generation-inductively coupled plasma optical emission spectrometry (ICP-OES) technique was developed to determine inorganic As, including total As, As(III), and As(V), in drinking water samples in optimized conditions as follows: wavelength of 193.7 nm, integration time of 5-10 s, RF power of 1.3 kW, and the flow rates of plasma gas and auxiliary gas of 15 and 0.2 l/min for ICP-OES, the sample flow rates of 1.2 ml/min, reductant, and acid 0.4 ml/min and carrier gas 0.3 l/min, 0.4% (w/v) NaBH 4 with 40% (w/v) KI within 10 min as a reductant for total As, 0.4% (w/v) NaBH 4 for As(III) and 2 mol/l HCl for hydride generation. As(V) was obtained from the difference between total As and As(III). The linear dynamic range was 1-100 g/l with a correlation coefficient of 0.9998. The limit of detection of total As, As(III), and As(V) was 0.38, 0.07, and 0.37 g/l, respectively. The limit of quantification of total As, As(III), and As(V) was 1.28, 0.24, and 1.17 g/l, respectively. 94.9-99.1% recovery for each As species was achieved. This fast and easy method was applied to determine arsenic in drinking water samples with satisfactory recovery (79-112%).