Method of detecting tautomeric cyclic 1,2-diones
US5661037A · kind A · utility
Inventors
Key dates
| Filing date | Jun 10, 1996 |
| Grant date | Aug 26, 1997 |
| Priority date | — |
| Expiry date | Jun 10, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/200833
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is a method of determining whether a solvent contains a tautomeric cyclic 1,2-dione. It is first determined whether the pH of the solvent is acidic (<5), basic (>9), or neutral (5 to 9). If the pH is neutral, an acid or a base is added to make the pH acidic or basic, respectively. The UV absorbance at a first wavelength between about 230 nm and about 270 nm and at a second wavelength between about 280 and about 320 nm is determined. If the pH is acid, it is changed to basic and, if it is basic, it is changed to acidic. The UV absorbance at the first and second wavelengths is again determined. The presence of a tautomeric cyclic 1,2-dione is indicated if the absorbance at the first wavelength was greater when the solvent was acidic and the absorbance at the second wavelength was greater when the solvent was basic. The concentration of the tautomeric cyclic 1,2-dione can be determined by multiplying the change in absorbance by a constant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.