HH-PLOT-Molecular sieve-II甲烷毛細管 環(huán)境空氣甲烷的測定HJ 604-2017

。

3.2

      非甲烷總烴 nonmethane hydrocarbons (NMHC)

指在本標準規(guī)定的測定條件下，從總烴中扣除甲烷以后其他氣態(tài)有機化合物的總和（除非另有說明，結(jié)果以碳計）。

4 方法原理

將氣體樣品直接注入具氫火焰離子化檢測器的氣相色譜儀，分別在總烴柱和甲烷柱上測定總烴和甲烷的含量，兩者之差即為非甲烷總烴的含量。

環(huán)境空氣甲烷的測定HJ 604-2017  測試譜圖：




Determination of ambient air methane HJ 604-2017
Determination of ambient air methane HJ 604-2017 Details:

Methane capillary column:

Stationary phase: Porous layer open tube molecular sieve column or other equivalent capillary column

Specifications: 30m*0.53mm*25um

Application: Ambient Air Determination of Total Hydrocarbons, Methane and Non-Methane Total Hydrocarbons Direct Injection-Gas Chromatography HJ 604-2017


HJ 604-2017 Ambient Air Determination of Total Hydrocarbons, Methane and Non-Methane Total Hydrocarbons Direct Injection-Gas Chromatography
1 Scope of application
      This standard specifies the direct injection-gas chromatography method for the determination of total hydrocarbons, methane and non-methane total hydrocarbons in ambient air.
      This standard applies to the determination of total hydrocarbons, methane and non-methane total hydrocarbons in ambient air, and also applies to the determination of total hydrocarbons, methane and non-methane total hydrocarbons in the air at monitoring points of fugitive emissions from pollution sources.

When the injection volume is 1.0ml, the detection limit of this standard for the determination of total hydrocarbons and methane is 0.06 mg/m3 (calculated as methane), and the lower limit of detection is 0.24 mg/m3 (calculated as methane); non-methane total hydrocarbons The detection limit is 0.07 mg/m3 (calculated by carbon), and the lower limit of determination is 0.28 mg/m3 (calculated by carbon).

2 Normative references
      This standard refers to the following documents or clauses thereof. For undated references, the valid edition applies to this standard.
      HJ 194 Technical Specification for Manual Monitoring of Ambient Air Quality
      HJ 664 Technical Specifications for Layout of Ambient Air Quality Monitoring Points (Trial)
      HJ 732 Sampling air bag method for volatile organic compounds in waste gas from stationary pollution sources
      HJ/T 55 Technical guidelines for monitoring fugitive emissions of air pollutants

3 Terms and Definitions

      The following terms and definitions apply to this standard.

3.1

      total hydrocarbons (THC)

Refers to the sum of gaseous organic compounds that respond on the hydrogen flame ionization detector of a gas chromatograph under the measurement conditions specified in this standard.

3.2

      nonmethane hydrocarbons (NMHC)

Refers to the sum of other gaseous organic compounds after deducting methane from total hydrocarbons under the measurement conditions specified in this standard (unless otherwise stated, the results are in carbon terms).

4 Principles of the method

The gas sample was directly injected into a gas chromatograph with a hydrogen flame ionization detector, and the contents of total hydrocarbons and methane were measured on the total hydrocarbon column and the methane column, respectively, and the difference between the two was the content of non-methane total hydrocarbons.

Determination of ambient air methane HJ 604-2017 test spectrum: