PetroFLAG Can Be Used to
The PetroFLAG system provides the user with a complete method for
analyzing soil samples for the presence of petroleum hydrocarbons. The procedure takes 15
minutes and up to 20 samples can be run concurrently. The complete analysis system is
available for under $700 and consumables run about $10 per test.
How PetroFLAG is Used:
Hydrocarbons are detected through a simple three step process.
After being weighed out, the soil sample is first extracted with a solvent that
effectively removes over 90% of the hydrocarbons present. The resulting extract is then
filtered through a unique, non-clogging system that removes all particulate matter, even
from clay and other difficult-to-filter samples.
The filtrate is then added to a vial which contains an aqueous
development solution. The vial is placed in the meter where a two channel turbidimeter
measures the absorbance of the mixture and converts the reading into parts per million of
petroleum hydrocarbons. The result is displayed on the unit's LCD readout. The instrument,
reagents, vials, and balance are all contained in a carrying case that weighs less than
The PetroFLAG System
PetroFLAG has been available since early 1995 and hundreds of
units are in use. Usersinclude state EPAs and DEPs as well as the Department of Energy and
the Corp of Engineers. PetroFLAG has received SW-846 draft method approval number 9074
from EPA's Office of Solid Waste.
The PetroFLAG system is designed to be used by those with little
or no experience in analytical or field chemistry. You will find that it is easier to use
than any other field test you have tried. Users should be aware of QA/QC and safety
procedures that are appropriate for field analysis. A free video is available that
explains how the system works and provides details on how to run it.
What are PetroFLAG's Uses and Limitations?
PetroFLAG tests for a broad range of hydrocarbons including diesel fuel, kerosene, crude
oil, motor oil, hydraulic fluid, grease, transformer oil, and #2,#4, and #6 fuel oils.
While the method is not specific for any particular hydrocarbon, if the type of
hydrocarbon is known, it may be accurately quantified.
If the hydrocarbon type is unknown, the instrument can be used as
a general screen so that no false negative results are generated. The detection range is
from 10 to 20000 parts per million. No chlorinated solvents are used in any part of the
procedure. Moisture does not affect test results up to saturation (20-25% water). Usable
temperature range is from 5°C to 45°C.
Light hydrocarbons such as fresh gasoline can be detected by
PetroFLAG but only at high concentrations (>1000 ppm). It is generally recommended that
PetroFLAG not be used for gasoline except as a general screen for high levels.
PetroFLAG does respond to PNAs such as anthracene and creosote
and may be used to detect this class of compounds. Response settings have not been
determined for PNAs and the response is not as linear as for other hydrocarbons.
The presence of naturally occurring hydrocarbons in soil, eg, vegetable oils, may cause
high readings with PetroFLAG. This high bias can be compensated for by calibrating the
instrument with a blank soil that contains an equivalent concentration of the naturally
occurring material. Such a soil is usually found in an area surrounding the site of
concern. PetroFLAG is unaffected by the presence of salt or surfactants. There are no
known sources of negative interference for PetroFLAG.
PetroFLAG can be used anywhere
Comparison to Laboratory Methods-
PetroFLAG has been rigorously evaluated against methods 8015B
(gas chromatography) and 418.1 (infrared analysis) at actual contaminated sites. As
detailed in Evaluation of a New Field Test Kit for Determining Total Petroleum Hydrocarbon
Concentrations in Soil at a Site Contaminated by Diesel Fuel by Keith Wright (available
from Dexsil), PetroFLAG was compared to both the GC and the IR methods.
The resulting correlations were 89% for 8015B and 92% for 418.1.
In a separate study of an oil and grease site (see Evaluation ofa Rapid Field Analytical
Test Kit for Assessing Hydrocarbon Soil Contamination, Keith Wright and David Jermstad,
available from Dexsil) the correlation between PetroFLAG and 418.1 was shown to be 90%
with no false negatives and two false positive results.
Other studies are also available from Dexsil. Laboratory results
for both 8015B and 418.1 may vary widely between laboratories because of different
preparation and extraction techniques, so, when confirming PetroFLAG results with these
methods, make sure that all of the details of the laboratory analysis are known.
[Dexsil, Clor-N-Oil, Clor-D-Tect, Clor-N-Soil, L2000 and
PetroFLAG are registered trademarks of Dexsil Corporation.]