ASTM D4629 Test Method for Trace Nitrogen in Liquid Petroleum Hydrocarbons
ASTM D4629 Standard Test Method for Trace Nitrogen in Liquid Petroleum Hydrocarbons by Syringe/Inlet Oxidative Combustion and Chemiluminescence Detection
3. Summary of Test Method
3.1 The sample of liquid petroleum hydrocarbon is introduced either by syringe or boat inlet system, into a stream of inert gas (helium or argon). The sample is vaporized and carried to a high temperature zone where oxygen is introduced and organically bound nitrogen is converted to nitric oxide (NO). The NO contacts ozone, and is converted to excited nitrogen oxide (NO2). The light emitted as the excited NO2 decays is detected by a photomultiplier tube and the resulting signal is a measure of the nitrogen contained in the sample.
4. Significance and Use
4.1 Some process catalysts used in petroleum and chemical refining may be poisoned when even trace amounts of nitrogenous materials are contained in the feedstocks. This test method can be used to determine bound nitrogen in process feeds and may also be used to control nitrogen compounds in finished products.
