5631. Lysalbinic Acid

Nomenclature

CAS number: 9006-58-0

Description and references

A colloidal substance prepd by the action of caustic alkalies on albumin, usually egg albumin, athough it also may be obtained from serum albumin or from casein (caseolysalbinic acid): Paal, Ber. 35, 2195 (1902); DE 129031 (1902); DE 132322 (1902). Composition: C 52.9%, H 7.0%, N 14.9%, S 1.2%.

Properties

Usually isolated as the Na salt, a brittle yellowish mass, readily sol in water, forming a colloidal soln which foams. It is precipitated by alc, and it may be purified by dialysis.

Derivative

Colloidal gold.

Description and references

Prepd by adding a soln of gold chloride to a soln of lysalbinic acid. The intensely red hydrosol is precipitated with alcohol and dried. The precipitate forms hard, bronze-colored granules which may be stored for a long time, yielding a red, colloidal gold soln upon addn of water. Analysis of dried granules shows about 30% Au. See Paal, Ber. 35, 2236-2244 (1902); DE 170433; DE 180730 (1906, 1907 to Kalle).

Use

As a protective colloid for metal sols, especially gold, silver, and mercury sols.