Pinpoint Leaks and Spills with NIR Spectroscopy
Contamination of soil due to leaks, spills and seepage is a worldwide problem usually diagnosed by costly and time consuming methods primarily using wet chemistry. Typically, Total Petroleum Hydrocarbon (TPH) measurements are used. Using a field portable spectrometer or spectroradiometer to measure TPH in soil is fast and non-destructive. The scan can be made in the field covering a full 350-2500nm spectrum and the results displayed on a handheld microcomputer, tablet, or laptop, Hydrocarbon spectra are usually characterized by four main absorption features at 1180 and 1380nm and 1730 and 2310nm. By looking at these bands, other compounds can be eliminated and the presence of hydrocarbons verified. In addition, by building a model based on known TPH samples from chemical analyses, spectroscopy can be combined with regression analysis to measure and identify different species of hydrocarbons in different soil components.
Scanning and analyzing vegetation chlorophyll can also be used to identify when vegetation shifts toward the “red edge” at 700nm and chlorophyll is lost. This is another indicator of potential oil and gas seepage.
SPECTRAL EVOLUTION’S full range, field portable spectrometers and spectroradiometers deliver fast, accurate, and flexible ways to measure both hydrocarbons in soil and changes in vegetation with:
- Fast collection of data in seconds with no sample prep or sample destruction
- Precision, accuracy, and a wealth of information, especially if the spectra are combined with chemometrics analysis
- Affordable measurement technology
- In situ measurement with portable, field-tested spectroradiometers and
A full range spectroradiometer such as the PSR+ 3500 provides:
- Spectral range 350-2500nm
- Reliable one-touch operation with autoshutter, autoexposure and auto-dark correction before each new scan – no optimization step required
- Small and lightweight with rechargeable lithium-ion batteries
- Superior signal-to-noise ratio: faster scan times and better reflectance measurement
- Single user operation with optional rugged PDA that provides a sunlight readable display plus the ability to tag spectra with GPS, digital images, and audio notes
- DARWin SP Data Acquisition software for ease-of-use – saves files in ASCII format for use with 3rd party software – no pre- processing necessary
- Optional EZ-ID mineral identification software with Custom Library Builder module to build your own library for regression analysis
Underground pipelines, refineries, storage tanks – all are potential sites for leaks, spills and seepage. The PSR+ 3500 can help researchers bring the power and non-destructive measurement capabilities of spectroscopy to bear on the search for contamination with fast and accurate measurement of TPH indicators.
Soil samples were scanned using a PSR+ spectroradiometer with EZ-ID mineral identification software and the SpecMIN mineral spectra library. Clay mineral alteration of smectite to kaolinite can be an indicator of hydrocarbon presence in soil.
Soil scans can provide critical information on TPH content associated with potential leaks and spillage.