Antioxidants

Mechanisms of antioxidants

• reducing agent

• inert atmosphere to prevent oxidation

Sodium Thiosulfate

• large, transparent, colorless crystals, cooling, bitter taste

• reagent for iodimetric/iodometric titratioms

• treatment for CN poisoning

Sodium Nitrite

• white to slightly yellow granular powder

• deliquescent and mild saline taste

• antidote to CN

Hypo-phosphorus Acid

• salts are used as food preservatives

• antioxidant: prevents the formation of free I2

Sodium Metabisulfite

• has odor of SO2

• white crystal or white to yellowish crystalline powder

Nitrogen

• inert gas

• protects chemicals, reagents, and pharmaceuticals from air oxidation

• production of inert atmosphere for easily oxidized products

Ligand

• usually anions or neutral molecules

• has lone pair or atleast one pair of non bonding e

Maximum coordination number

maximum # of ligands that can be accommodated by metal ion

Coordination sphere

space around the metal occupied by the ligand

Complex ion

• metal and its associated ligand

• Ion with a charge

Coordination compound

the neutral complex or the complex ion with its counter ions

Monodentate Ligands

one non bonded pair of electrons to donate to metal ion

Bidentate ligands

2 donor sites in complex

Polydentate

more than 2 complexation sites

Chelation

covers metal cations and improves solubility

Chelating agenrs

polydentate ligands for chelate formation

Sequestering agents

when polydentate ligand is used to improve the solubility and or stabilize a metal ion by chelarion

Calcium Disodium Edetate

• white crystalline granule or powder

• treatmenr of heavy metal poisoning, lead (plumbism)

• can also be used in copper, nickel, cadmium, zinc, chromium, and manganese poisoning

• has calcium and is used when calcium level is normal

Disodium Edetate

• has no calcium

• used to treat hypercalcemic diseases

• has high affinity for calcium so when it is introduced in the system it deactivates it

Dimercaprol (BAL)

• arsenic, mercury, gold poisoning

• improves the excretion of lead and copper (Wilson’s disease)

• contraindicated in iron, cadmium, and selenium poisoning

Penicillamine

• capable of forming complexes with copper, iron, mercury, lead, and gold

• treatment for gold dermatitis

• used to improve excretion of copper

• Treats Wilson’s disease

Deferoxamine

• produced naturally by Streptomyces pilosus as a ferric complex

• does not have strong affinity with ferrous

• removes excess iron in the body

• used when ferric ion is high