TPH (Total Petroleum Hydrocarbons)
TPH (Total Petroleum Hydrocarbons)
TPHSoil_None_Other_IMM_Eng_Ody.fm Page 11 of 12
For example: If a 0.5 mL water sample is diluted to 50 mL and tested, the
calibrator levels for diesel fuel in water would represent 200, 500, 1000, and
2000 ppm respectively.
Sample Collection and Storage
Analyze the samples as soon as possible after collection. If the samples must be
stored, collect them in glass or Teflon
®
containers that have been washed with
soap and water and rinsed with methanol. The container should be capped with
a Teflon-lined cap. If a Teflon cap is not available, aluminum foil rinsed in
methanol may be used as a substitute cap liner.
When collecting water samples, fill the container completely (no head space) and
cover the container with a tightly-sealed lid immediately after collection.
For Soil: Store the samples at 4 °C (40 °F) for no longer than 14 days.
For Water: Chill the sample in an ice bath or refrigerator to limit the loss of
volatile compounds. Store samples no longer than 24 hours.
Interferences
Summary of Method
This method provides semi-quantitative screening based on thresholds for TPH
as diesel fuel in the following concentrations:
Hach immunoassay tests use antigen/antibody reactions to test for specific
organic compounds in water and soil. Antibodies specific for TPH are attached
to the walls of plastic cuvettes. They selectively bind and remove TPH from
complex sample matrices. A prepared sample and a reagent containing enzyme-
conjugate molecules (analyte molecules attached to molecules of an enzyme) are
added to the Antibody Cuvettes. During incubation, enzyme-conjugate
molecules and TPH compete for binding sites on the antibodies. Samples with
higher levels of analyte will have more antibody sites occupied by TPH and
fewer antibody sites occupied by the enzyme-conjugate molecules.
Table 3
mL Sample Multiplier
0.5 100
1.0 50
2.0 25
5.0 10
10.0 5
25.0 2
Interfering Substance Interference Levels and Treatments
Chlorine in water samples
Interfere above 2 ppm
Remove with sodium thiosulfate
Soil 20, 50, 100, 200 ppm as diesel fuel
Water 2, 5, 10, 20 ppm as diesel fuel
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