Development of Inductively Coupled Plasma Atomic Emission Spectrometry for Arsenic Determination in Wine

Abstract

This paper describes a direct method for arsenic determination and speciation in wine samples by hydride atomic emission spectrometry with inductively coupled plasma (ICP-AES). Optimization of the method included investigation of several parameters that impact the intensity of spectral lines: concentration of reaction media (hydrochloric acid), reduction reagent concentration (sodium borhydride), power generator and the carrier flow rate. The effect of ethanol on spectral lines was especially investigated because it enabled arsenic determination without prior preparation. Optimal conditions for As(III) were 8 mol/L HCl and 0.1% NaBH(4), for dimethylarsinite (DMA) determination 0.005mol/L HCl and 0.02% NaBH(4), and for As(V) 4 mol/L HCl and 2% NaBH(4). Total arsenic was determined in samples after their treatment in a microwave digestion unit. Results were compared to the FIA method, arsenic was determined with the standard addition method, and the results showed agreement. Detection limits (mu g/L) for determination of As(V), DMA, and As(III) were found to be 0.4, 0.6, and 0.10, respectively. Good recoveries (89.9-102.0%) of added spikes were obtained for all samples. The proposed method has been validated by means of reference materials and the results obtained were in agreement with certified values.