| Synonyms | Hydroxypropyl alginate |
| 1,2-propanediol ester of alginic acid |
| Propylene glycol alginate |
| Definition | |
| Chemical name | Propane-1,2-diol ester of alginic acid; varies in composition according to its degree of esterification and the percentage of free and neutralised carboxyl groups in the molecule |
| Chemical formula | (C9H14O7)n (esterified) |
| Molecular weight | 10 000-600 000 (typical average) |
| Assay | Yields, on the anhydrous basis, not less than 16 % and not more than 20 % of CO2 of carbon dioxide |
| Description | Nearly odourless, white to yellowish brown fibrous or granular powder |
| Identification | |
A.Positive test for 1,2-propanediol and alginic acid after hydrolysis | |
| Purity | |
| Loss on drying | Not more than 20 % (105 oC, 4 hours) |
| Total propane-1,2-diol content | Not less than 15 % and not more than 45 % |
| Free propane-1,2-diol content | Not more than 15 % |
| Water-insoluble matter | Not more than 2 % on the anhydrous basis |
| Arsenic | Not more than 3 mg/kg |
| Lead | Not more than 5 mg/kg |
| Mercury | Not more than 1 mg/kg |
| Cadmium | Not more than 1 mg/kg |
| Heavy metals (as Pb) | Not more than 20 mg/kg |
| Total plate count | Not more than 5 000 colonies per gram |
| Yeast and moulds | Not more than 500 colonies per gram |
| E. coli | Negative in 5 g |
| Salmonella spp. | Negative in 10 g |
