Huang et al. 2020 - hijiki arsenic growth stages

Huang et al. measured total arsenic, inorganic arsenic, and arsenic species in cultivated edible hijiki (Sargassum fusiforme) at different growth stages. The primary occurrence data are whole-plant dry-weight values for native and Korean hijiki varieties grown in Zhejiang, China. Total arsenic, inorganic arsenic, arsenate, arsenite, DMA, and MMA are kept distinct below.

Key numbers

Table 1 reports total arsenic and inorganic arsenic in mg/kg dry weight as mean ± SD of triplicate assays:

The Results text summarizes Table 1 as total arsenic 35.05 to 84.37 mg/kg (dry weight) and inorganic arsenic 24.21 to 58.00 mg/kg dry weight.

Table 2 reports four arsenic species in mg/kg dry weight as mean of triplicate assays:

The source states that extraction efficiency for speciation ranged from 75 to 90%, inorganic arsenic, especially arsenate, was the main arsenic form, and the species order was As(V) > As(III) > DMA > MMA. The text states that DMA was 1 - 4% and MMA was 1 - 3% of total arsenic.

For uptake kinetics, Figure 3 and the Results text report arsenate uptake Vmax of 1202 ng/g DW min and Km of 12.91 µmol/L; the corresponding arsenite uptake values are described in the text as 619 ng/DW min and 4.591 µmol/L.

Methods (brief)

The study sampled cultivated hijiki in 2016 at monthly intervals from January to May for the native variety and January to March for the Korean variety. Whole-plant samples of 250 g fresh weight were collected, washed with seawater, transported to the lab, washed with tap water and ultrapure water, freeze-dried, and ground. Total arsenic was measured by HVG-FAAS after microwave digestion of 0.2 g milled sample in concentrated nitric acid. Inorganic arsenic was extracted from 1.00 g hijiki powder with 20 ml of 50% (v/v) hydrochloric acid at 60°C for 18 h, then determined by HVG-FAAS. Arsenic species were extracted with 10% (v/v) HCl and water at 70°C, treated with hydrogen peroxide, filtered through a 0.45 µm membrane, and analyzed by SA-10 Atomic Fluorescence Speciation Analyzer.

Implications

This source is routeable edible-hijiki occurrence evidence because it reports dry-weight tAs and iAs by growth stage for cultivated whole plants, and separately identifies As(V), As(III), DMA, and MMA. Downstream extraction should treat As(V) and As(III) as inorganic arsenic species, while retaining the Table 1 whole-plant iAs values as the main occurrence summary. The organ-distribution figure/prose conflict should not be used for product-row values without a later audit decision.

Wiki pages this source may touch

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

Verification notes

• Identity checks before writing found no existing source page for DOI 10.15666/aeer/1801_19411952, raw handle MFK_1801-19411952, or cite key huang2020-hijiki-arsenic-growth-stages.
• All Key numbers were rechecked against /tmp/hmi-seaweed-009.txt, extracted with pdftotext -layout; Tables 1 and 2 were also visually checked against rendered PDF pages 5 and 7.
• Source-side inconsistency: Table 2 repeats Table 1 tAs means but uses different native-variety SDs for February-April (17.97, 16.48, 22.17 instead of Table 1’s 7.97, 6.48, 4.17). Both tables are transcribed as printed.
• Source-side inconsistency: the organ-distribution prose reports rhizoid/leaf/air sac/stem values of 31.92, 27.23, 20.66, and 14.66 mg/kg dry weight, but Figure 1 visually shows a different order and scale; those organ values are not used as routeable occurrence numbers here.
• Speciation check: Table 1 iAs and Table 2 As(V)/As(III) are inorganic arsenic context; total arsenic is not substituted for inorganic arsenic. DMA and MMA are kept as organic arsenic species.
• Units and basis are preserved as mg/kg dry weight, %, ng/g DW min, and µmol/L; no conversions were performed.
• Evidence tier B reflects peer-reviewed primary edible-seaweed occurrence and speciation data, but with internal source inconsistencies and limited QA/QC detail in the extracted text.
• Brand firewall: no sampled brands are reported.

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.