Sitelab's
portable field analyzers use ultraviolet fluorescence technology; a very
selective detection method useful for measuring many types of petroleum
contaminants. UVF spectrometry's principle of operation relies on the
electronic configuration of the molecular structure for organic compounds.
Aromatic hydrocarbons, which include
ring-shaped compounds such as benzene,
naphthalene, benzo[a]pyrene and many others, both excite and emit energy at specific
wavelengths. The fluorometer's response of each sample is measured by
the instrument on a linear, multi-point calibration curve using certified
standards sensitive to the wavelengths of interest. Samples are
extracted in methanol solvent using disposable test kits and then placed
into the analyzer for analysis, where the concentration is displayed in only
a few seconds.
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Versatile, Accurate & Easy to Operate!
Different
petroleum products contain different types and amounts of aromatic
hydrocarbons, which fluoresce differently from one another.
Many contaminated sites also contain weathered fuel products which
have degraded and changed in composition over time. Conventional laboratories use a variety of U.S. EPA
or other state regulatory test methods
using Gas Chromatography (GC) instrumentation. GCs can
separate "TPH" into
gasoline range, diesel and oil range and PAH hydrocarbon fractions,
as does Sitelab.
Sitelab provides a variety of different UVF Calibration
Kits to choose from in order to best match the source of your spill
and provide maximum performance when comparing your field results to
the confirmatory lab. Since our analyzers are
calibrated using similar types of certified standards laboratories
use for GC analysis and are fitted with high precision excitation
and emission optics, test results generated directly correlate, providing very
accurate and reliable results.
This method
is recognized by regulatory agencies as a field screening device.
The UVF-3100 was
evaluated by U.S. EPA for TPH in soil measurement
and ranked highest compared to six other manufacturer's devices.
Sitelab Corporation was
certified by New Jersey DEP beginning in
2009. It has been used on sites all over the world. |
»See schematic diagram
showing UV fluorescence
UVF Limitations?
Fluorescence cannot detect one compound from another. Some
projects may require you to test and report individual compounds.
Response factors can be used to estimate Benzo[a]Pyrene, for
example, when testing for PAHs. Confirmatory lab analysis
testing split-samples with a certified laboratory is
typcially required. |
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Sitelab results directly correlate to
certified laboratory test methods...
Sitelab's GRO,
EDRO and TPH-Oil calibration kits are specially formulated products
which contain both aromatic and aliphatic hydrocarbons.
Samples contaminated with gasoline, jet fuel and many other
petroleum sources contain mixtures of
both aromatic and aliphatics. The
aliphatics compounds are inert; they do not fluoresce, but they are
accounted for when calibrating the instrument and measuring samples
using the TD-500D and UVF-3100.
How Low Can It Go?
Due to UVF's high sensitivity, minimum
detection limits are in the low ppm or ppb range, capable of meeting or exceeding most regulatory clean up levels.
Detection limits vary depending
on which analyzer and calibration kit is used. Detection limits are dictated by the lowest
calibrator included with each calibration kit and are the same for
soil, sediment or water samples. A solvent blank is used to
'zero' the instrument during the calibration process. Sample
readings between zero and the lowest calibrator are reported as
non-detect (ND). See instrument specification sheets below for
more details:
Other Advantages?
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Unlike other methods, UVF does not suffer from natural organic interferences
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Samples take just a few minutes
from start to finish to prepare and analyze
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Forensic fingerprinting is also available to identify the type or
age of petroleum |
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What
Fluoresces?
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Jet Fuels (JP-4, JP-8, etc.)
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Heating Oils, No 2. Fuel Oil
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Heavy Fuel Oils, No. 6 Fuel Oil
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Motor Oils and Lubricating Oils
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Coal Tars, Coal Ash and Creosote
What doesn't fluoresce?
Fluorescence is not sensitive to straight-chain, aliphatic
hydrocarbons. This includes the methanol or hexane solvents
used for analysis. UVF cannot detect contaminants such as
TCE, PCE, other SVOC solvents or synthetic oils.
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