ASTM D8478-23 - Standard Test Method for N-Hexane Recoverable Total Oil and Grease and Total Petroleum Hydrocarbons in Water by ATR-Infrared Determination

1.1 This test method covers the determination of total oil and grease, and total petroleum hydrocarbons in produced water and wastewater by an infrared (IR) determination of n-hexane extractable substances from the sample. Included in this estimation of total oil and grease are any other compounds soluble in the n-hexane.

1.2 This test method defines total oil and grease in produced water and wastewater as that which is extractable in the test method and measured by IR absorption from 3.34 µm to 3.54 µm (2825 cm^-1 to 2994 cm^-1). Similarly, this test method defines total petroleum hydrocarbons in produced water and wastewater as that oil and grease which is not adsorbed by silica gel in the test method, and is measured by IR absorption from 3.34 µm to 3.54 µm (2825 cm^-1 to 2994 cm^-1). Alternative methods for total oil and grease or total petroleum hydrocarbons, or both, can produce differing results.

1.3 This method covers the range of 5 mg/L to 175 mg/L for total oil and grease and the range of 5 mg/L to 50 mg/L for total petroleum hydrocarbons. The range may be extended to a lower or higher level by extraction of a larger or smaller sample volume collected separately.

1.4 This test method uses horizontal attenuated total reflectance (HATR) with a cubic zirconia crystal.

1.5 This test method is intended as a field test only and should be treated as such. This method is not intended to replace laboratory-based regulatory methods currently in use.

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

1.7 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See Guide D3856 for more information.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.