Measurement of low phosphonate concentrations
US5270216A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1992 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Feb 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/166666
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A process for measurement of low levels of phosphonates in brine waters wherein the phosphonate samples are acidified with hydrochloric acid promptly upon removal from an oil or gas well to prevent phosphonate precipitation or adsorption. The hydrochloric acid acidified phosphonate is digested in the presence of an oxidizing agent at elevated temperature and pressure for sufficient time to oxidize substantially all of the phosphonate to orthophosphate. The phosphorous containing compound is extracted with an organic extractant, preferably selected from the group consisting of methyl iso-butyl ketone/cyclohexane mixture and ethyl acetate, followed by color development for absorption spectrophotometry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.