García-Salgado et al. 2012 - brown-algae arsenolipids

García-Salgado et al. identified and quantified arsenosugar phospholipids and arsenic hydrocarbons in two dried commercial brown macroalgae, Wakame and Hijiki. The paper reports whole-powder total arsenic and lipid-soluble organoarsenic species, not inorganic arsenic. Values below therefore keep whole-powder total arsenic and individual arsenolipids separate.

Key numbers

The paper reports whole dry-powder total arsenic as µg As g-1 dry mass:

The lipid fraction contained 6.7% of initial total arsenic for Wakame and 1.6% for Hijiki.

Table 2 quantifies arsenolipids in µg As kg-1 and as percentage of lipid arsenic. Data are mean ± s.d. from three analyses, each involving extraction, clean-up, and HPLC-ICPMS; column recoveries ranged from ~70 to 110%.

Figure 2 states that As-HC332 and As-HC360 were present in both Wakame and Hijiki, while As-HC388 was present in Wakame but not Hijiki by the confirmatory GC-MS discussion; Table 2 nevertheless reports a small Hijiki As-HC388 HPLC-ICPMS quantified value of 22 ± 2 µg As kg-1.

For QA/QC, the paper reports NIES No. 9 Sargasso certified total arsenic 115 ± 5 µg As g-1 and measured 116 ± 2 µg As g-1 (n = 3).

Methods (brief)

Total arsenic analyses were performed on dry powders, extracts, or combined silica-column fractions by ICP-MS in helium collision-cell mode after microwave-assisted acid mineralization. Arsenolipids were extracted in triplicate from Wakame and Hijiki with chloroform/methanol, washed with 1% w/v bicarbonate solution, cleaned on silica, and analyzed by reversed-phase HPLC with simultaneous ICPMS and electrospray MS detection. HPLC used a Zorbax Eclipse XDB-C8 column with an acetic acid/methanol gradient; accurate masses were measured with an LTQ Orbitrap XL in FTMS high-resolution positive-scan mode.

Implications

This source adds seaweed organoarsenic speciation context for commercial Wakame and Hijiki. It should not be treated as an inorganic-arsenic occurrence paper: the quantified species are arsenosugar phospholipids, arsenic hydrocarbons, and two unidentified arsenolipid peaks. Downstream extraction should keep whole-powder tAs, lipid-fraction arsenic percentage, and named arsenolipid species distinct.

Wiki pages this source may touch

• seaweed-kelp-foods
• seaweed
• arsenic-total

Verification notes

• Identity checks before writing found no existing source page for DOI 10.1071/EN11164, raw handle MFK_10-1071-en11164, or cite key garcia-salgado2012-brown-algae-arsenolipids.
• All Key numbers were rechecked against /tmp/hmi-seaweed-006.txt, extracted with pdftotext -layout, and the whole-powder and Table 2 units were visually checked against rendered PDF pages because the text layer renders µg as mg.
• Speciation check: the source reports tAs and lipid-soluble organoarsenic compounds. It does not report inorganic arsenic, so iAs is not used in the frontmatter or Key numbers.
• Units and basis are preserved as µg As g-1 dry mass, %, µg As kg-1, and µg As g-1; no conversions were performed.
• Evidence tier B reflects peer-reviewed primary speciation data with exact species and QA/QC, but only two commercial materials and a rapid-communication scope.
• Brand firewall: no sampled brands are reported. Instrument, column, and reference-material names are retained only as scientific method details.

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.