Rapid and simple determination of As in bottled birch saps by hydride generation inductively coupled plasma optical emission spectrometry

Abstract

ABSTRACT A strategy was developed for the determination of total As in birch saps (BSs) by hydride generation (HG) coupled with inductively coupled plasma optical emission spectrometry (ICP-OES). We proposed and validated a simple and robust HG-ICP-OES method with no need for tedious and long sample preparation before measurements. Corresponding As hydride was generated in reaction with NaBH4 (1.0%) in acidic conditions (10 mol L−1 HCl) after pre-reduction of As(V) to As(III) in a KI (0.5%)-ascorbic acid (2.0%)-HCl (3 mol L−1) mixture. Several different sample preparation procedures, including digestive and non-digestive approaches, were tested in order to improve the detectability of As using HG-ICP-OES. Reactivity of As towards HG under conditions of a real sample was investigated to check potential interfering effects coming from undecomposed sample matrix constituents. The proposed method included the direct analysis of untreated samples (only pre-reduction prior to HG) and precision (<6% as relative standard deviation), accuracy (94.7–108.7% as recoveries) and sensitivity (limit of detection at 0.26 ng mL−1) that was suitable for trace analysis. An absence of matrix effects allowed external calibration for quantification of As. Applicability of the method was demonstrated by determination of As in several commercially available bottled BSs.