Heavy Metal Index
Ask the IndexAboutIndex Pro

Analytical techniques for arsenic speciation

Cite this pageVersion history

Summary

This 2025 mini-review from Chiba University (Japan) summarises published analytical techniques for arsenic speciation across food, environmental (water, soil), and biological (urine, blood) matrices. The review covers LC-ICP-MS (the gold standard), GC-MS after derivatisation, colorimetric methods (molybdenum blue), HG-AAS, voltammetry, and emerging microfluidic electrochemical devices. It provides a concise reference for analytical method selection and LOD comparison, and contextualises the toxicity ranking of arsenic species.

Key numbers

  • Toxicity ranking (from review): As(III) greater than As(V) greater than DMA(V) greater than MMA(V) greater than AsB (essentially non-toxic)
  • DMTA(V) (thio-DMA): produced by gut bacteria from DMA(V); classified as potentially carcinogenic (IARC Group 2B 2024 for DMA; thioarsenicals under emerging review)
  • Anion-exchange HPLC-ICP-MS: typical LOD less than 1 ug/L for most species; analysis time approximately 15 min
  • Molybdenum blue colorimetric LOD: 410-1,350 ug/L (too high for food safety monitoring)
  • DMA reported as most prevalent urinary arsenic species (approximately 60-80% in general populations)
  • As(V) predominant in oxidising environments; As(III) in reducing environments and more toxic

Methods

Mini-review. No primary measurements. Literature searched through 2024. Covers: anion-exchange LC-ICP-MS (Hamilton PRP-X100 or equivalent; (NH4)2HPO4 or (NH4)2CO3 mobile phases with 1-3% methanol; 15 min analysis); reversed-phase for arsenolipids; CE-ICP-MS (high sensitivity, LOD 0.3 ng/mL); HG-AAS; voltammetry; microfluidic devices.

Implications

The confirmation that DMTA(V) is produced by intestinal bacteria from DMA is relevant to the microbiome pathway for arsenic toxicity: the gut microbial community can convert dietary arsenic species into thioarsenicals with potentially higher carcinogenicity. For food analysis, anion-exchange HPLC-ICP-MS remains the validated reference method for inorganic arsenic (iAs) in rice and other staple foods; the review provides method selection rationale.

Update history

No substantive edit history is available in this build. The full commit record is available in git.

Referenced by