ASTM D7678

Significance and Use

The presence and concentration of total petroleum hydrocarbons, as well as oil and grease, in domestic and industrial wastewater is of concern to the public because of its deleterious aesthetic effect and its impact on aquatic life.

Regulations and standards have been established that require monitoring of total petroleum hydrocarbons as well as oil and grease in water and wastewater.

1. Scope

1.1 This test method covers the determination of total petroleum hydrocarbons (TPH) in water, and waste water, that are extractable from an acidified sample with a cyclic aliphatic hydrocarbon (for example cyclohexane), and measured by IR absorption in the region of 1370 -1380 cm^-1 (7.25 -7.30 microns). Polar substances are removed by clean-up with Florisil.

1.2 The method also considers the volatile fraction of petroleum hydrocarbons which is lost by gravimetric methods that require solvent evaporation prior to weighing, as well as by solventless IR methods that require drying of the employed solid phase material prior to measurement. Similarly, a more complete fraction of extracted petroleum hydrocarbon is accessible by this method as compared to GC methods that use a time window for quantification, as petroleum hydrocarbons eluting outside these windows are also quantified.

1.3 This method defines oil and grease in water and wastewater as that which is extractable in the test method and measured by IR absorption in the region of 1370-1380 cm^-1
(7.25 – 7.30 microns).

1.4 This method covers the range of 0.5 to 1000 mg/L and may be extended to a lower or higher level by extraction of a larger or smaller sample volume collected separately.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.