Stabilised formazin composition, method of preparation and diluent for formazin composition
US10717869B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 2016 |
| Grant date | Jul 21, 2020 |
| Priority date | — |
| Expiry date | Mar 7, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L61/22
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A stabilised aqueous formazin composition comprises 100 parts by weight water; up to 0.03 parts by weight formazin polymer; 0.4 to 5 parts by weight hexamethylenetetramine; and a buffer composition, wherein the buffer composition is adjusted to maintain a pH of the formazin solution in a range between 8.4 and 10. The stabilised formazin composition has a turbidity of 400 NTU or less. A diluent for preparing the stabilised formazin composition from a formazin stock composition is provided, wherein the diluent comprises hexamethylenetetramine in a concentration of between 4 and 50 g/l and a buffer composition adjusted to a pH of the diluent in a range of from 8.4 to 10.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.