Reinke 1975 - Fish and shellfish inorganic arsenic

Reinke and colleagues developed a selective extraction and polarographic method for arsenite and arsenate in fish and shellfish tissue. The occurrence-relevant table reports total arsenic and total inorganic arsenic, defined by the paper as As3+ plus As5+, for eight fish or shellfish tissues. The key finding is that high total arsenic in several marine foods was not matched by high inorganic arsenic, except for lobster hepatopancreas at 0.9 ppm.

Key numbers

Table 4 reports inorganic arsenic and total arsenic content of white muscle from fish and shellfish, as mean duplicate analyses in ppm.

The method section reports that levels down to about 0.5 ppm inorganic arsenic could be determined, but an interfering wave was noticed at the lower limit. The abstract states that tested specimens had total arsenic levels up to 40.5 ppm and little inorganic arsenic. Table 3 reports duplicate recovery of arsenite and arsenate added as a 1:1 mixture by weight to lobster hepatopancreas: 30 µg added gave 73 and 80% recovery; 20 µg gave 83 and 78%; 10 µg gave 93 and 91%; 5 µg gave 98 and 98%; 2.5 µg gave 97 and 96%; and 1 µg gave 120 and 86%.

Methods (brief)

Arsenite, as arsenic trichloride, was extracted into benzene from strongly acidified tissue homogenates, then back-extracted into water and analyzed polarographically in 1 N HCl. Arsenate left in the homogenate was reduced to arsenite with cuprous ion and isolated by the same extraction procedure; treating the homogenate with cuprous ion before extraction produced the paper’s total inorganic arsenic measurement. Total arsenic values were reported beside the inorganic arsenic values, but the table does not describe a separate arsenic speciation profile beyond arsenite and arsenate.

Implications

This source supplies early seafood occurrence evidence showing that total arsenic and inorganic arsenic must remain separate for fish and shellfish. The lobster tail row is especially useful as a speciation example: total arsenic was 40.5 ppm, while inorganic arsenic was reported as <0.5 ppm. The lobster hepatopancreas row should be kept distinct from edible white-muscle rows because it is an organ tissue with 0.9 ppm inorganic arsenic.

Verification notes

• PDF text was extracted with pdftotext -layout to /tmp/f3_resolve_texts/reinke1975.txt; the title page, abstract, methods, Tables 2-4, and discussion paragraphs were checked.
• The OCR rendered some Table 4 <0.5 cells as co.5, a.5, or 4.5; PDF page 9 was rendered to /tmp/reinke_pages/reinke-09.png and visually checked before recording every censored inorganic-arsenic value as <0.5.
• No DOI was visible in the extracted text or title page; DOI search, raw-handle search, and cite-key checks found no existing source page before creation.
• Units are preserved as source-reported ppm, µg, percent recovery, and 1 N HCl; no conversion was performed.
• Speciation: inorganic arsenic is source-defined as arsenite plus arsenate (As3+ plus As5+). Total arsenic remains tAs; no total arsenic value is promoted to inorganic arsenic.
• Brand firewall: no retail brands were reported.
• Frontmatter product and ingredient slugs were checked against docs/gpt-collaboration/taxonomy-snapshot.md; species-level slugs for halibut, shrimp, haddock, crab, mackerel, herring, and lobster are absent, so broad seafood/fish/shellfish routing is used.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.