COINAGE METALS

Coinage metals

used in ancient coinage and ornaments; occur freely in metallic state; highly malleable; form complexes or chelates

Copper

only reddish metal; derived from Latin cuprum; essential trace element; cofactor for cytochrome oxidase; enhances iron utilization; protein precipitant; respiratory pigment hemocyanin; copper ions (Cu²⁺) are blue in solution

Toxicity of Copper

Wilson’s disease; metal fume fever

Antidote for Copper toxicity

penicillamine; BAL (dimercaprol)

Alloys of Copper

brass; bronze; Devarda’s alloy

Cupric sulfate pentahydrate

CuSO₄·5H₂O; blue vitriol/blue stone;

Copper Sulfate

used in Fehling’s test, Benedict’s test, Barfoed’s test; classic tests for aldehydes and ketones; antidote for phosphorus poisoning

Benedict’s solution

copper sulfate reagent for reducing sugar detection (blue → brick red ppt)

Fehling’s solution

copper-based reagent for aldehyde sugar detection

Barfoed’s solution

distinguishes monosaccharides (fast reaction) vs disaccharides (slow reaction) using copper ions

Isotope of Copper 64

used in mineral metabolism studies

Component of Bordeaux Mixture

CaO and H2O

Copper acetoarsenite

synonym is Paris Green; insecticide; toxic pigment

Copper (II) ferrocyanide

Hatchett’s brown; insecticide

Cupric hydrogen arsenite

Scheele’s green; historic pigment; toxic

Silver

derived from Latin argentum; second most malleable metal; second best conductor of electricity; oligodynamic property; used for bone fixation and styptic

Pharmacologic actions of Silver

antimicrobial; disinfectant; styptic

Toxicity of Silver

argyria

Antidotes for Silver toxicity

sodium thiosulfate; potassium ferricyanide

Silver nitrate

AgNO₃; lunar caustic / lapiz infernalis / indelible ink / caustic pencil; wart removal; ophthalmic antiseptic.

Neonatal conjunctivitis

Nerisseria genorhoae

Ammoniated silver nitrate

Howe’s solution; used for dental protective; Tollens’ reagent component; desensitizing agent;

Silver trinitrophenolate (silver picrate)

treats trichomoniasis and moniliasis; prolonged use → argyria & nephritis

Silver iodide

insoluble; poisonous

Mild silver protein

Argyrol; antiseptic for the eyes

Strong silver protein

Protargol; germicide and disinfectant; strong antiseptic for ears, nose, throat

Colloidal silver protein

Collargol; general germicide

Test for Silver using HCl

produces white precipitate AgCl

Test for Silver using H₂S

produces black precipitate Ag₂S₃

Gold

derived from Latin aurum; most malleable and ductile metal; best electrical conductor; “King of all Metals”

Gold is dissolved by

aqua regia (HCl + HNO₃)

Aurothioglucose (Solganal®)

IM; treatment for rheumatoid arthritis and gout; antidote: BAL

Gold sodium thiomalate (Myochrysine®)

IM; treatment of RA and gout

Auranofin (Ridaura®)

PO; only oral gold preparation; treatment for RA, gout, glossitis

BAL

british antilewisite