ASTM D5705 Test Method for Measurement of Hydrogen Sulfide in the Vapor Phase Above Residual Fuel Oils
1. Scope
1.1 This test method covers the field determination of hydrogen sulfide (H2S) in the vapor phase (equilibrium headspace) of a residual fuel oil sample.
1.2 The test method is applicable to liquids with a viscosity range of 5.5 mm2/s at 40°C to 50 mm2/s at 100°C. The test method is applicable to fuels conforming to Specification D396 Grade Nos. 4, 5 (Heavy), and 6.
1.3 The applicable range is from 5 µmol/mol to 4000 µmol/mol (micromoles per mole) (5 ppm v/v to 4000 ppm v/v (parts per million by volume)).
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.5 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
2.1 ASTM Standards:
D396 Specification for Fuel Oils
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D6021 Test Method for Measurement of Total Hydrogen Sulfide in Residual Fuels by Multiple Headspace Extraction and Sulfur Specific Detection
D7621 Test Method for Determination of Hydrogen Sulfide in Fuel Oils by Rapid Liquid Phase Extraction
3. Terminology
3.1 Definitions:
3.1.1 equilibrium headspace, n - the vapor space above the liquid in which all vapor components are in equilibrium with the liquid components.
3.1.2 residual fuel oil, n - a fuel oil comprising a blend of viscous long, short, or cracked residue from a petroleum refining process and lighter distillates blended to a fuel oil viscosity specification.
3.1.2.1 Discussion - Under the conditions of this test (1:1 liquid/vapor ratio, temperature, and agitation) the H2S in the vapor phase (sample's headspace) will be in equilibrium with the H2S in the liquid phase.
