ASTM D5453 for total sulfur in light hydrocarbons, motor fuels and motor oils
ASTM D5453 Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Motor Fuels and Motor Oils by Ultraviolet Fluorescence
1. Scope
1.1 This test method covers the determination of total sulfur in liquid hydrocarbons, boiling in the range from approximately 25 to 400°C, with viscosities between approximately 0.2 and 20 cSt (mm2/S) at room temperature.
1.2 Three separate interlaboratory studies (ILS) on precision, and two other investigations that resulted in an ASTM research report, have determined that this test method is applicable to naphthas, distillates, oils, ethanol, Fatty Acid Methyl Ester (FAME), and motor fuels; such as gasoline, oxygen enriched gasoline (M-85, RFG), diesel, biodiesel and jet fuel. Samples containing 1.0 to 8000 mg/kg total sulfur can be analyzed (Note 1).
NOTE 1 - Estimates of the pooled limit of quantification (PLOQ) for each of the five precision studies were calculated. Values ranged between less than 1.0 and less than 5.0 mg/kg (see Section 8 and 15.1).
1.3 This test method is applicable for total sulfur determination in liquid hydrocarbons containing less than 0.35 % (m/m) halogen(s).
1.4 The values stated in SI units are to be regarded as standard.
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. See 3.1, 6.3, 6.4, Section 7, and 8.1.
2. Referenced Documents
2.1 ASTM Standards:
D1298 Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
D4052 Test Method for Density and Relative Density of Liquids by Digital Density Meter
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D6299 Practice for Applying Statistical Quality Assurance Techniques to Evaluate Analytical Measurement System Performance
3. Summary of Test Method
3.1 A hydrocarbon sample is either directly injected or placed in a sample boat. The sample or boat, or both, is inserted into a high temperature combustion tube where the sulfur is oxidized to sulfur dioxide (SO2) in an oxygen rich atmosphere. Water produced during the sample combustion is removed and the sample combustion gases are next exposed to ultraviolet (UV) light. The SO2 absorbs the energy from the UV light and is converted to excited sulfur dioxide (SO2*). The fluorescence emitted from the excited SO2* as it returns to a stable state, SO2, is detected by a photomultiplier tube and the resulting signal is a measure of the sulfur contained in the sample. (Warning - Exposure to excessive quantities of ultraviolet (UV) light is injurious to health. The operator must avoid exposing any part of their person, especially their eyes, not only to direct UV light but also to secondary or scattered radiation that is present.)
4. Significance and Use
4.1 Some process catalysts used in petroleum and chemical refining can be poisoned when trace amounts of sulfur bearing materials are contained in the feedstocks. This test method can be used to determine sulfur in process feeds sulfur in finished products, and can also be used for purposes of regulatory control.
