Determination of Inorganic Arsenic in Marine Food Samples by Hydrochloric Acid Distillation and Flow-Injection Hydride-Generation Atomic Absorption Spectrometry

A simple, rapid, and reliable method was developed for determination of inorganic As in biological samples such as fish fillet. Inorganic AS was distilled from the sample as AsCl3 with HCI. The separated inorganic AS was determined by flow-injection hydride-generation atomic absorption spectrometry after prereduction with Kl and HCI. The influences of various concentrations of Kl, ascorbic acid, and HCI in the prereduction stage; NaBH4 as the reductant; and HCI as the carrier solution on analytical results were studied. Digestion was performed in a Kjeldahl digestion system for 75 min with 4 mL nitric acid and 1 mL sulfuric acid at 380°C. The concentrations of inorganic As in samples were less than 0.1 mg/kg dry weight for fish fillet and somewhat higher for crustaceans and bivalve molluscs. The total and inorganic As contents of various marine biological samples and certified reference materials were determined.