See USEPA ETV/Site Program report.

References:  Roberts, R.M. and  Khalaf, A. A. Friedel Crafts Alyklation Chemistry:  A Century of Discovery.  Marcel Dekker, Inc., NY, p. 790 (1984); Schmid, George H.  Organic Chemistry.  Mosby-YearBook, Inc.,QD251.2S354, p.935 (1996).

Detection of total petroleum hydrocarbons (TPH) in soil can indicate contamination from leaking underground storage tanks (USTs), petroleum refineries, or other fuel sources.

The RemediAid^(TM) Total Petroleum Hydrocarbon Test Kit is a rapid, simple field test for measuring petroleum hydrocarbon contamination in soil.  The patented is based upon the Friedel-Crafts reaction with one fundamental difference -- the intermediate that is formed in the solvent is the colored species that is measured.

The RemediAid Kit determines TPH across a wide range of soil types and petroleum products.  RemediAid allows the user to analyze for specific fractions, including BTEX, PAH, diesel fuel, leaded and unleaded gasoline, weathered gasoline, brent crude, and lubricating oil.

The Test Method.  A pre-measured sample of soil is added to a reaction tube that contains anhydrous sodium sulfate, a drying agent.  20 ml dichloromethane is then added to the reaction tube.  This organic solvent extracts the petroleum hydrocarbons from the soil sample.  Finally, a vacuum sealed ampoule, containing aluminum chloride, draws in a predetermined volume of the hydrocarbon containing solvent.  Interference from polar organic matter is eliminated by the use of a silica-packed column mounted on the tip of the vacuum sealed ampoule.  The hydrocarbons in the solvent react with the aluminum chloride to produce a soluble colored product directly proportional to the petroleum hydrocarbon concentration in the sample.  The absorbance of the sample is measured in a portable, battery powered, LED based colorimeter and converted to mg/kg (ppm) hydrocarbon in the soil by use of a formula.