Zein
» Zein is a prolamine derived from corn (Zea mays Linné [Fam. Gramineae]).
Packaging and storage—
Preserve in tight containers.
Identification—
A:
Dissolve about 0.1 g in 10 ml of 0.1 N sodium hydroxide, and add a few drops of cupric sulfate TS. Warm in a water bath: a purple color develops.
B:
To a test tube containing 25 mg of Zein add 1 mL of nitric acid. Agitate vigorously: the solution becomes light yellow. Further addition of about 10 mL of 6 N ammonium hydroxide produces an orange color.
C:
It is insoluble in water, but 1 g of it in 10 mL of a mixture of isopropyl alcohol and water (85:15), at a temperature of about 37
, yields a clear to cloudy solution.
, yields a clear to cloudy solution.
Microbial enumeration tests 
61
and Tests for specified microorganisms 62—
The total bacterial count does not exceed 1000 cfu per g, and the tests for Salmonella species and Escherichia coli are negative.
61 and Tests for specified microorganisms 62—
The total bacterial count does not exceed 1000 cfu per g, and the tests for Salmonella species and Escherichia coli are negative.
Loss on drying 731—
Dry it at 105 for 2 hours: it loses not more than 8.0% of its weight.
731—
Dry it at 105 for 2 hours: it loses not more than 8.0% of its weight.
Residue on ignition 281:
not more than 2.0%.
281:
not more than 2.0%.
Heavy metals, Method II 231:
0.002%.
231:
0.002%.
Nitrogen content—
Proceed as directed under Nitrogen Determination, Method I 461: the nitrogen content is not less than 13.1% and not more than 17.0%, on the dried basis.
461: the nitrogen content is not less than 13.1% and not more than 17.0%, on the dried basis.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
Chromatographic Column—
| Topic/Question | Contact | Expert Committee |
| Monograph | Hong Wang, Ph.D.
Scientist 1-301-816-8351 |
(EM205) Excipient Monographs 2 |
| 61 |
Radhakrishna S Tirumalai, Ph.D.
Senior Scientist 1-301-816-8339 |
(MSA05) Microbiology and Sterility Assurance |
| 62 |
Radhakrishna S Tirumalai, Ph.D.
Senior Scientist 1-301-816-8339 |
(MSA05) Microbiology and Sterility Assurance |
USP32–NF27 Page 1380
Pharmacopeial Forum: Volume No. 34(4) Page 1019
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.