Method of separating monohydrate of L-cysteine hydrochloride
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsShyoichiro Miyahara, Toshiaki Kamiguchi, Tadashi Hashimukai, Kazunari Nitta
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Abstract
Hydrochloric acid is added to a solution containing L-cysteine, L-cystine, L-serine and an inorganic salt until it contains at least 15% by weight of hydrochloric acid. The solution is held at a temperature of at least 20.degree. C. so that the L-cystine and the inorganic salt may form a solid, and the solid is removed from the solution. The solution is cooled to a temperature not exceeding 10.degree. C., so that crystallization may take place to form the monohydrate of L-cysteine hydrochloride. The monohydrate is separated from the L-serine in the solution.
Claims5
A method of separating L-cysteine from a solution containing L-cysteine, L-cystine, L-serine and an inorganic salt, comprising:
- adding hydrochloric acid to said solution until it contains at least 15% by weight of hydrochloric acid;
- holding said solution at a temperature of at least 20.degree. C. to separate a solid containing said L-cystine and said salt from said solution;
- cooling said solution to a temperature not higher than 10.degree. C. to allow crystallization to form the monohydrate of L-cysteine hydrochloride;
- and
- separating said monohydrate from said L-serine in said solution.
Dependencies are inferred from the claim text.