Reinsch Test
Definition
Classical screen for arsenic, antimony, mercury and bismuth. A clean copper strip is immersed in the acidified sample (concentrated HCl, near-boiling) for 30 to 60 minutes. A grey to black metallic deposit on the copper indicates arsenic. The strip is then heated in a dry tube to sublime arsenic trioxide as octahedral crystals that confirm under the microscope.
- Primary use
- Screening for arsenic, antimony, mercury, and bismuth in toxicology samples
- Positive indicator
- Grey to black metallic deposit on the copper strip or foil
- Confirmatory step
- Heating the deposit to sublimate arsenic trioxide as octahedral crystals, visible under microscope
Common questions
What metals does the Reinsch test detect?+
The test screens for arsenic, antimony, mercury, and bismuth. It is a classical method used when these metals are suspected in a sample. The most common application is arsenic detection in toxicology.
How do you know if the Reinsch test is positive?+
A grey to black metallic deposit appears on the copper strip or foil when the target metals are present. To confirm arsenic specifically, the strip is heated in a tube. Octahedral arsenic trioxide crystals visible under the microscope confirm the metal's identity.
What are the steps in a Reinsch test?+
A clean, polished copper strip is immersed in the acidified sample (usually concentrated HCl) at near-boiling temperature for 30 to 60 minutes. If a deposit forms, the strip is removed and heated in a dry tube, and the sublimate crystals are examined microscopically to identify the specific metal.
Related terms
- Arsenic (As)
- Metalloid; trivalent arsenite (As III) is 60 times more toxic than pentavalent arsenate (As V). Thiol-group blocker that poisons mitochondrial enzymes (pyruvate...
- 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...
- Dry Ashing
- Viscera or hair is dried and incinerated in a muffle furnace at 450 to 550 degrees Celsius. Inorganic ash is dissolved in...
- Hydride Generation (HG-AAS)
- Sensitivity booster for As, Sb and Se. Sample plus NaBH4 in acid liberates AsH3 / SbH3 / SeH2 gas, which is swept...
- Lead (Pb)
- Cumulative neurotoxin from chronic occupational exposure (battery recycling, smelter work), leaded paint, contaminated cosmetics (low-grade sindoor, surma, kohl), and adulterated Ayurvedic preparations....
- Marsh Test
- Sensitive 1836 method for arsenic in which the acidified sample is added to zinc and dilute sulphuric acid. The evolved arsine gas...
- Marsh Test (1836)
- Confirmatory test for arsenic devised by James Marsh after the Bodle case (1832), in which Marsh was unable to convince a jury...
- Mees Lines
- Transverse white bands across the fingernails that follow acute or repeated chronic exposure to arsenic, thallium or selenium. Appear 4 to 8...
- Mercury (Hg)
- Three toxic forms: elemental (vapour from broken thermometers, dental amalgam), inorganic salts (mercuric chloride, corrosive sublimate), and organic (methylmercury from biomagnification, ethylmercury...
- Speciation
- Determining the chemical form of a metal in a sample, not just the total. Critical for arsenic because As(III) trivalent arsenite is...
- Thallium (Tl)
- The 'poisoner's poison' because thallium sulphate is tasteless, odourless and colourless. Substitutes for potassium in cellular transport. Alopecia at 2 to 3...
Explained in these topics
- Metallic Poisons: Arsenic, Mercury, Lead and ThalliumClassical wet screen for arsenic, mercury, antimony and bismuth. A polished copper foil is dipped in HCl-acidified viscera. A grey to black deposit on the copp...
- Toxic Metals and Anions: Arsenic, Lead, Mercury, Thallium and BeyondClassical screen for arsenic, antimony, mercury and bismuth. A clean copper strip is immersed in the acidified sample (concentrated HCl, near-boiling) for 30 t...