Method NWTPH-Dx

Scope

The NWTPH-Dx method is intended to replace the Oregon’s Department of Environmental Quality TPH-D and Washington’s Department of Ecology WTPH-D methods and to present a more comprehensive approach to semi-volatile petroleum product analyses. NWTPH-Dx adapts Oregon’s TPH, Washington’s WTPH and EPA SW-846 Methods 3510, 3540/3550 and 8000 and covers the quantitative and qualitative analysis of semi-volatile petroleum products, i.e. jet fuels through heavy fuel oils, in soil and water.

Diesel Range Organics (DRO) corresponds to the range of alkanes from C10 to C28 and covering a boiling point range of approximately 170 C – 430 C.

The method involves extracting the samples with methylene chloride and injecting a portion of the extract into a gas chromatograph (GC) equipped with a flame ionization detector (FID). This method specifies criteria for the identification and quantitation of semi-volatile petroleum products. A clean-up procedure, which may be used to aid in the removal of non-petroleum based organic interferences, i.e. biogenic interferences, has been included. When the type of petroleum product is unknown, #2 diesel will initially be used as the default petroleum standard.

The method is applicable for the identification, by pattern matching (“fingerprinting”), and quantitation of semi-volatile petroleum products. These include kerosene, jet fuels, diesel oils, fuel oils, lubricating oils, hydraulic fluids, mineral oils and insulating oils, e.g. transformer oils. In general, those petroleum products which do not contain a substantial volatile fraction, i.e. the majority of the components eluting outside of the gasoline range, should be analyzed by this method.

-Oregon’s Department of Environmental Quality TPH-D and Washington’s Department of Ecology WTPH-D methods

Method Data

Analyte List

N/A

*Please contact our project management team for more information about reporting limits and other specific project needs.