Stability of volatile organic compounds in environmental water samples during transport and storage
- Oak Ridge National Lab., TN (USA)
The stability of volatile organic compounds in environmental water samples has been studied, particularly with respect to the establishment of preanalytical holding times. Methods have been developed for the preparation of standard samples containing known concentrations of volatile organics. Three water samples were used: distilled water, surface water, and groundwater. Samples were stored at both room temperature and under refrigeration. Data were collected over a 365-day period by gas chromatography/mass spectrometry. In water samples containing low chloride content (distilled water), rapid dehydrohalogenation of tetrachloroethane to trichloroethylene occurred. Such degradation was also evident in the surface water and groundwater samples stored at room temperature. A less rapid conversion of trichloroethane to dichloroethylene occurred in distilled water samples stored at 25{degree}C. Subsequently, experiments were conducted to determine the value of reduced pH in sample preservation. It was shown that acidification with hydrochloric acid effectively prevented degradation and allowed indefinite storage. However, sampling and analytical considerations make the use of HCl impractical. Therefore, a study was carried out using sodium bisulfate and ascorbic acid as preservatives. Both substances effectively preserved the samples, but sodium bisulfate proved to have several advantages over ascorbic acid. Samples preserved with either acid were stable over the 112-day experimental period.
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6231207
- Journal Information:
- Environmental Science and Technology; (USA), Journal Name: Environmental Science and Technology; (USA) Vol. 24:11; ISSN ESTHA; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
CHROMATOGRAPHY
COMPILED DATA
DATA
GAS CHROMATOGRAPHY
GROUND WATER
HYDROGEN COMPOUNDS
INFORMATION
MASS SPECTROSCOPY
MATTER
MEASURING METHODS
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
PRESERVATION
SAMPLE PREPARATION
SEPARATION PROCESSES
SPECTROSCOPY
STABILITY
SURFACE WATERS
VOLATILE MATTER
WATER