Total arsenic and inorganic arsenic content in Norwegian fish feed products

Abstract

Samples of complete feedingstuffs for fish, and fishmeals from the Norwegian Fish Feed Monitoring Programme in 2003 were analysed for their total arsenic and inorganic arsenic contents. Microwave assisted wet digestion with nitric acid and hydrogen peroxide was used for the sample preparation for total arsenic analysis by ICPMS. Microwave assisted alkaline‐alcoholic dissolution of the sample was used for liberation of inorganic arsenic prior to analysis by anion‐exchange chromatography High Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry (HPLC–ICPMS). Concentrations in the ranges of 3.4–8.3 and 0.010–0.061 mg kg−1 for complete feedingstuffs were found for total arsenic and inorganic arsenic, respectively. The results are in accordance with typical arsenic levels for fish reported in the literature and indicate that no transformation of chemical arsenic species occurs during the processing of complete feedingstuffs. Several of the complete feedingstuff samples had total arsenic concentrations above the EU maximum content of 6 mg kg−1 in complete feedingstuffs for fish and complete feedingstuffs for fur animals. However, the species of toxicological relevance, i.e. inorganic arsenic, constitutes less than 1.2% of the total arsenic concentration in these samples. The data illustrate that fish feed with high levels of arsenic, but low levels of inorganic arsenic are at risk of being unnecessarily rejected from the fish feed market. Additionally, the results suggest that the maximum level for total arsenic in fish feed should be re‐evaluated and future maximum levels should be based on the chemical species of toxicological relevance, namely inorganic arsenic, rather than on total arsenic.

Development and validation of an SPE HG-AAS method for determination of inorganic arsenic in samples of marine origin

“…In oyster samples (N07), the iAs concentration was up to 0.14 mg kg −1 , and in all samples of trout (N011), fish feed (N01) and fish meal (N01), concentrations below the LOD (0.08 mg kg −1 ) were found. The contents were in accordance with previously reported results for samples of marine origin, including fish (<0.002-0.006 mg kg −1 ) [7], shellfish (0.001-0.26 mg kg −1 ) [19] and fish feed (0.01-0.06 mg kg −1 ) [39]. The iAs levels detected in the oyster and fish samples were much lower than the MLs for fish (2 mg kg −1 ) and molluscs (1 mg kg −1 ) in Australia and New Zealand [13].…”

Organic forms of trace elements as feed additives: Assessment of risks and benefits for farm animals and consumers

“…Most of the literature is devoted to As speciation and addressed both naturally occurring [34][35][36] and synthetic arsenocompounds such as the feed additives p-arsanilic acid and 4-hydroxy-3-nitrophenyl-arsonic acid (roxarsone) [37][38][39][40]. As far as essential TEs are concerned, most of the work on chemical speciation dealt with Se.…”

“…Se speciation in selenized yeast has been extensively studied, especially in the last decade; selenomethionine is the most abundant Se species in enzymatic extracts of selenized yeast, accounting for ≥60 % of the total Se content [41]. HPLC-ICP-MS has been the analytical approach commonly used in these studies following proteolytic extraction for liberation of selenoamino acids from proteins; separation of Se species was achieved mainly through ion-pairing reversed phase, cation-exchange and anion-exchange chromatography [31][32][33][34][35]. Most recent studies employed molecular mass spectrometry for structural confirmation/identification.…”

Levels of total arsenic in edible fish and shellfish obtained from two coastal sectors of the Atacama Desert in the north of Chile: Use of non-migratory marine species as bioindicators of sea environmental pollution

“…Fish, crustaceans and molluscs show arsenic contents in the range of 1-100 mg kg −1 of dry weight. [8] Fish directly accumulate metals (such as arsenic) through the ingestion of particle material in suspension in water, food consumption and ion exchange from dissolved metals through the lipophilic membranes (e.g., the gills).…”