HJ 38-2017 Determination of Total Hydrocarbons, Methane and Non Methane Total Hydrocarbons in Waste Gas from Fixed Pollution Sources Gas Chromatography Method
1、 Scope of application
This standard specifies the gas chromatography method for determining total hydrocarbons, methane, and non methane total hydrocarbons in exhaust gases from fixed pollution sources.
This standard is applicable to the determination of total hydrocarbons, methane, and non methane total hydrocarbons in organized emissions from fixed pollution sources.
When the injection volume is 1.0 ml, the detection limits for total hydrocarbons and methane determined by this method are both 0.06 mg/m3 (calculated as methane),
The lower limit of determination is 0.24 mg/m3 (calculated as methane); The detection limit of non methane total hydrocarbons is 0.07 mg/m3 (calculated as carbon), and the determination is
The lower limit is 0.28 mg/m3 (based on carbon).
2、 Product Overview
Total hydrocarbons (THC)
Refers to the gaseous state that responds on the hydrogen flame ionization detector of a gas chromatograph under the measurement conditions specified in this standard
The total sum of organic compounds.
Non methane hydrocarbons (NMHC)
Refers to the total sum of other gaseous organic compounds after deducting methane from total hydrocarbons under the measurement conditions specified in this standard (excluding
Unless otherwise specified, the results are based on carbon.
3、 Method principle
Inject the gas sample directly into a gas chromatograph equipped with a hydrogen flame ionization detector, and measure it on the total hydrocarbon column and methane column respectively
The difference between the content of total hydrocarbons and methane is the content of non methane total hydrocarbons. At the same time, replace the sample with hydrocarbon free air and measure oxygen
The response value on the total hydrocarbon column is used to deduct the interference of oxygen in the sample on the determination of total hydrocarbons.