Speciation
Definition
Determining the chemical form of a metal in a sample, not just the total. Critical for arsenic because As(III) trivalent arsenite is 60 times more toxic than As(V) pentavalent arsenate, and methylated organic species like arsenobetaine from seafood are essentially non-toxic. Modern speciation runs by HPLC-ICP-MS.
Related terms
- Bhasma
- Calcined heavy-metal preparation in classical ayurvedic and siddha pharmacopoeia. Includes naga bhasma (lead), parad bhasma (mercury), tamra bhasma (copper). Heavy metals are...
- Chelation Therapy
- Administration of a polydentate ligand that forms a stable water-soluble complex with the metal cation and increases urinary excretion. BAL (dimercaprol) is...
- Marsh Test
- Sensitive 1836 method for arsenic in which the acidified sample is added to zinc and dilute sulphuric acid. The evolved arsine gas...
- Mees Lines
- Transverse white bands across the fingernails that follow acute or repeated chronic exposure to arsenic, thallium or selenium. Appear 4 to 8...
- Reinsch Test
- Classical screen for arsenic, antimony, mercury and bismuth. A clean copper strip is immersed in the acidified sample (concentrated HCl, near-boiling) for...
Explained in
- Toxic Metals and Anions: Arsenic, Lead, Mercury, Thallium and BeyondDetermining the chemical form of a metal in a sample, not just the total. Critical for arsenic because As(III) trivalent arsenite is 60 times more toxic than A...