Lorenc et al. 2020 - arsenic species in marine algae products
Lorenc and colleagues developed and validated a combined HPLC/ICP-MS and UPLC/ESI-MS/MS workflow for arsenic in algae products. The occurrence-relevant data are the total arsenic and arsenic-speciation values in Table 2 for five algae/seaweed materials, including a commercial cooked/dried hijiki product, nori sheets, serrated wrack, and two reference materials. Unknown arsenic and arsenosugar species are kept separate from inorganic arsenic.
Key numbers
Table 2 reports total arsenic before extraction as mg kg-1 (c ± SD) and extracted/speciated arsenic as mg kg-1 (c ± U, k = 2). No unit conversion was performed.
| Sample | Native tAs | Extraction | Extracted tAs | AsB | As(III) | DMA | As(V) | uAs |
|---|---|---|---|---|---|---|---|---|
| Sample 1, NMIJ CRM 7405-a Hijiki | 34.38 ± 0.99 | Water, UAE | 17.88 ± 0.68 | <LOD | 0.853 ± 0.056 | <LOD | 2.83 ± 0.14 | 79% |
| Sample 1, NMIJ CRM 7405-a Hijiki | 34.38 ± 0.99 | Water:methanol, UAE | 9.12 ± 0.23 | <LOD | <LOD | <LOD | 6.59 ± 0.32 | 28% |
| Sample 1, NMIJ CRM 7405-a Hijiki | 34.38 ± 0.99 | Water, MAE | 16.52 ± 0.34 | <LOD | <LOD | <LOD | 7.39 ± 0.36 | 55% |
| Sample 1, NMIJ CRM 7405-a Hijiki | 34.38 ± 0.99 | Water:methanol, MAE | 26.76 ± 0.70 | <LOD | <LOD | <LOD | 7.37 ± 0.35 | 72% |
| Sample 2, Hijiki cooked/dried, milled | 72.6 ± 2.7 | Water, UAE | 66.0 ± 1.5 | <LOD | 0.952 ± 0.063 | <LOD | 5.64 ± 0.27 | 90% |
| Sample 2, Hijiki cooked/dried, milled | 72.6 ± 2.7 | Water:methanol, UAE | 36.54 ± 0.73 | <LOD | 1.468 ± 0.097 | 0.766 ± 0.040 | 5.94 ± 0.29 | 78% |
| Sample 2, Hijiki cooked/dried, milled | 72.6 ± 2.7 | Water, MAE | 48.94 ± 0.087 | <LOD | 1.147 ± 0.075 | <LOD | 5.48 ± 0.26 | 86% |
| Sample 2, Hijiki cooked/dried, milled | 72.6 ± 2.7 | Water:methanol, MAE | 57.99 ± 0.93 | <LOD | 1.168 ± 0.077 | <LOD | 5.95 ± 0.29 | 88% |
| Sample 2a, Hijiki cooked/dried, mortar-ground | not separately reported | Water, UAE | 59.6 ± 1.2 | <LOD | 2.63 ± 0.17 | 0.669 ± 0.035 | 4.87 ± 0.23 | 86% |
| Sample 2a, Hijiki cooked/dried, mortar-ground | not separately reported | Water:methanol, UAE | 11.29 ± 0.16 | <LOD | 1.233 ± 0.081 | <LOD | 4.81 ± 0.23 | 46% |
| Sample 2a, Hijiki cooked/dried, mortar-ground | not separately reported | Water, MAE | 60.7 ± 2.0 | <LOD | 1.195 ± 0.079 | <LOD | 4.12 ± 0.20 | 91% |
| Sample 2a, Hijiki cooked/dried, mortar-ground | not separately reported | Water:methanol, MAE | 55.1 ± 1.5 | <LOD | 1.248 ± 0.082 | 0.596 ± 0.031 | 4.71 ± 0.23 | 88% |
| Sample 3, Nori sheets for sushi | 19.28 ± 0.45 | Water, UAE | 11.85 ± 0.43 | <LOD | 7.88 ± 0.52 | <LOD | <LOD | 34% |
| Sample 3, Nori sheets for sushi | 19.28 ± 0.45 | Water:methanol, UAE | 16.51 ± 0.77 | <LOD | <LOD | <LOD | <LOD | 100% |
| Sample 3, Nori sheets for sushi | 19.28 ± 0.45 | Water, MAE | 13.83 ± 0.65 | <LOD | 8.97 ± 0.59 | <LOD | <LOD | 35% |
| Sample 3, Nori sheets for sushi | 19.28 ± 0.45 | Water:methanol, MAE | 14.96 ± 0.70 | <LOD | <LOD | <LOD | <LOD | 100% |
| Sample 4, Serrated Wrack | 19.37 ± 0.51 | Water, UAE | 2.82 ± 0.12 | <LOD | 1.292 ± 0.085 | <LOD | <LOD | 54% |
| Sample 4, Serrated Wrack | 19.37 ± 0.51 | Water:methanol, UAE | 10.37 ± 0.30 | <LOD | 1.291 ± 0.085 | <LOD | <LOD | 88% |
| Sample 4, Serrated Wrack | 19.37 ± 0.51 | Water, MAE | 5.35 ± 0.16 | <LOD | 1.098 ± 0.072 | <LOD | <LOD | 79% |
| Sample 4, Serrated Wrack | 19.37 ± 0.51 | Water:methanol, MAE | 11.40 ± 0.35 | <LOD | 1.252 ± 0.082 | <LOD | <LOD | 89% |
| Sample 5, NIST SRM 3232 Kelp Powder | 45.4 ± 1.4 | Water, UAE | 4.649 ± 0.069 | <LOD | <LOD | <LOD | <LOD | 100% |
| Sample 5, NIST SRM 3232 Kelp Powder | 45.4 ± 1.4 | Water:methanol, UAE | 14.59 ± 0.59 | <LOD | 0.911 ± 0.060 | <LOD | <LOD | 94% |
The abstract summarizes edible algae tAs as (19.28 ± 0.45) mg kg-1 to (72.6 ± 2.7) mg kg-1, As(III) as <LOD to (8.97 ± 0.59) mg kg-1, As(V) as <LOD to (5.95 ± 0.29) mg kg-1, DMA as <LOD to (0.766 ± 0.040) mg kg-1, and unknown arsenic species as 28% to 100% of extracted tAs.
Reference-material checks and method figures:
- NMIJ CRM 7405-a Hijiki tAs was
(34.38 ± 0.99) mg kg-1versus certified(35.8 ± 0.9) mg kg-1. - NIST SRM 3232 Kelp Powder tAs was
(45.4 ± 1.4) mg kg-1versus certified(38.3 ± 1.34) mg kg-1; the source states this was not in as good accordance as the NMIJ CRM. - The source reports LODs of
0.041 mg kg-1for tAs,0.12 mg kg-1for extracted tAs,0.55 mg kg-1for AsB,0.61 mg kg-1for As(III),0.57 mg kg-1for DMA,0.64 mg kg-1for MMA, and0.55 mg kg-1for As(V). - MMA was not detected in any sample. AsB was detected only in one Fucus serratus extract.
UPLC-HRMS identification context from Table 4 includes DMA(V), arsenate(V), MMMTA(V), MTA(V), DMAE, DMDTA(V), MMDTA(V), DMAA, pentylarsonic acid, dimethylarsinoylribose, multiple methylated arsenosugars, and one unknown arsenic compound. The authors report a high variety of As-sugars (12 compounds) and eight additional simple organic arsenic compounds; these organoarsenic identifications are not collapsed into inorganic arsenic.
Methods (brief)
The study analyzed five seaweed materials: NMIJ CRM 7405-a Hijiki, a cooked/dried Sargassum fusiforme hijiki product, Pyropia yezoensis nori sheets for sushi, Fucus serratus serrated wrack, and NIST SRM 3232 Kelp Powder. Nori and hijiki were ground before digestion/extraction; NMIJ CRM, NIST SRM, and serrated wrack were not further ground. Total arsenic used microwave-assisted digestion with nitric acid and hydrogen peroxide at 200 °C, followed by ICP-DRC-MS monitoring 91AsO+ with 73Ge+ internal standard.
Speciation used ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) with water or water:methanol (1:1, v/v) after nitric-acid extraction was discarded because it changed As speciation. For each extraction, 200 mg algae material was extracted with 20 mL extracting agent for 30 min; MAE was at 60 °C and UAE at room temperature. HPLC/ICP-DRC-MS used a Hamilton PRP-X100 anion-exchange column. UPLC/ESI-MS/MS was used for unknown arsenic-species identification.
Implications
This source provides a method-centered but routeable arsenic-speciation dataset for algae/seaweed products. It supports seaweed/kelp food and algae/seaweed supplement context with total arsenic and source-measured As(III), As(V), DMA, and unknown-organoarsenic fractions. Because the source’s conclusion emphasizes arsenosugars and other unknown organoarsenic species, downstream extraction must preserve speciation and must not treat total arsenic or arsenosugars as inorganic arsenic.
Wiki pages this source may touch
Verification notes
- Identity checks before writing found no existing source page for DOI
10.1016/j.talanta.2020.121384, raw handleMFK_lorenc2020, title text, or cite keylorenc2020-marine-algae-arsenic-species. - All Key numbers were rechecked against
/tmp/hmi-seaweed-043.txt, extracted withpdftotext -layout. Table 2 was transcribed as available in the extracted text; NIST SRM 3232 appears with two UAE rows in the text layer, while the prose states its MAE signals were broad and could not be assigned to specific compounds. - Units and bases are preserved as
mg kg-1,%,mg,mL,min, and°C; no unit conversion was performed. - Speciation check: As(III), As(V), DMA, AsB, MMA, unknown arsenic, and arsenosugar/organic species remain separate. No tAs value or arsenosugar identification is promoted to iAs.
- Brand firewall: the source does not name consumer brands; the page records product forms/material types and CRM/SRM identities only.
- Missing-slug check: no missing product or ingredient slug blockers. Exact nori, hijiki, serrated wrack, Fucus, and kelp powder terms remain in source text while frontmatter uses broad seaweed/kelp and algae/seaweed supplement slugs.
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.
| Commit | Date | Description |
|---|---|---|
| 4039d20 | 2026-06-10 | scope: broaden ingest to the full upstream+downstream literature (marine, atmospheric, attribution, exposure, toxicology) — inclusion is the default |