Sadee et al. 2023 — Arsenic speciation in vegetables: review
Sadee and colleagues provide a systematic review of arsenic speciation, toxicity, and analytical methods as applied to vegetable matrices. The review covers: the chemical forms of arsenic (inorganic species As3+, As5+; organic arsenicals); health effects of prolonged inorganic arsenic exposure (skin, lung, bladder, liver, kidney, and prostate cancer; cardiovascular, respiratory, and renal effects); occurrence data from multiple countries; extraction methods for arsenic species from vegetable matrices; and hyphenated chromatographic-detection techniques (primarily HPLC coupled to ICP-MS or AAS variants). Regulatory context is discussed including FDA’s 100 ppb action level for iAs in infant rice cereal and EU maximum levels. The review explicitly acknowledges that the toxicity of arsenic depends critically on its chemical form, making speciation essential for meaningful risk assessment.
Key numbers
- Review covers >300 naturally occurring arsenicals; four principal oxidation states: As−III, As0, AsIII, AsV
- Inorganic As (iAsIII and iAsV) classified as most hazardous; organic species (arsenobetaine, arsenocholine) generally less toxic
- Literature-compiled range for total As in vegetables: varied by species and growing region; contaminated-soil vegetables can exceed 1 mg/kg dw (exact values in reviewed primary studies)
- FDA regulatory threshold cited: 100 ppb (µg/kg) iAs in infant rice cereal
- EU maximum levels for arsenic in food covered in the review but no single comprehensive table reproduced in this source page
- Extraction efficiencies from vegetables depend on solvent and method; phosphate buffer and methanol mixtures commonly used; ultrasonic and microwave extraction compared
- Chromatographic separation: ion exchange (anion/cation) and reversed-phase HPLC are the dominant approaches; detection by ICP-MS, HG-AAS, HG-AFS
Methods (brief)
Narrative review; no primary data generated. Synthesizes published studies on extraction, separation, and detection methods for As speciation in vegetables. Figures show a flow diagram of extraction-separation-detection approaches. Source from Salahaddin University-Erbil, Iraq, published in RSC Advances (Royal Society of Chemistry).
Implications
Certification: Reinforces the non-negotiable iAs/tAs speciation distinction (CLAUDE.md Part 14). Total As measurements in vegetables cannot substitute for iAs when setting limits or interpreting risk.
Courses: Reference for analytical methods module — explains why HPLC-ICP-MS is the gold standard for arsenic speciation in food matrices.
App: Vegetable ingredient arsenic risk requires speciated data; total arsenic alone insufficient for reliable hazard scoring in the app.