Method for testing earth samples for contamination by organic contaminants
US5976883A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 1996 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Sep 30, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/25125
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Provided is a method for testing earth samples for contamination by organic contaminants, and particularly for aromatic compounds such as those found in diesel fuel and other heavy fuel oils, kerosene, creosote, coal oil, tars and asphalts. A drying step is provided in which a drying agent is contacted with either the earth sample or a liquid extract phase to reduce to possibility of false indications of contamination that could occur when humic material is present in the earth sample. This is particularly a problem when using relatively safe, non-toxic and inexpensive polar solvents such as isopropyl alcohol since the humic material tends to be very soluble in those solvents when water is present. Also provided is an ultraviolet spectroscopic measuring technique for obtaining an indication as to whether a liquid extract phase contains aromatic organic contaminants. In one embodiment, the liquid extract phase is subjected to a narrow and discrete band of radiation including a desired wave length and the ability of the liquid extract phase to absorb that wavelength of ultraviolet radiation is measured to provide an indication of the presence of aromatic organic contaminants.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.