1.1This test method covers the determination of the dissolved gases methane, ethane, ethylene, and propane in drinking, waste, and ground waters, including domestic wells whether naturally occurring or resulting from commercial activities, or both. This test method has an analytical range from 10 µg/L to 11 000 µg/L for methane, and 10 µg/L to 5000 µg/L for ethane, ethylene, and propane. If a sample has a dissolved gas concentration above the calibration range, the sample would require dilution. Other analytical ranges may be used as long as the instrument calibration encompasses the desired range and demonstrates adequate linearity.
1.2This test method is applicable to samples collected at a nominal ambient pressure. Samples collected under high pressures, that is, above ambient pressure, may not be accurately analyzed using this method.
1.3This test method is applicable to a variety of dissolved gases; however, for the present standard, only methane, ethane, ethylene, and propane were validated. In order to validate for a gas not listed in this method, the analyst would need to establish the saturation concentration of the new gas, and establish a valid curve, method detection limits, and demonstration of capability following the procedures outlined in this method.
1.4It is the analyst’s responsibility to ensure the validity of this test method for dissolved gases other than methane, ethane, ethylene, and propane and other sample matrices.
1.5Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.6A single laboratory study was done in order to establish precision and bias for the surrogate (see Section 16).
1.7This 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.
1.8This 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.