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

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.

Graphical abstract

KEYWORDS:

• Birch sap
• arsenic
• sample preparation
• hydride generation
• ICP-OES

Acknowledgments

This study was financed by a statutory activity subsidy from Polish Ministry of Science and Higher Education for the Faculty of Chemistry, Wroclaw University of Science and Technology.

Disclosure statement

There are no conflicts to declare.