Jiedao IslandGC1690F(S)Introduction to Non Methane Total Hydrocarbon Gas Chromatography:

Product name: Non methane total hydrocarbon gas chromatograph

model:GC1690F(S)

Manufacturer: Jiedao

GC1690F(S)Non methane total hydrocarbon gas chromatograph

Non methane（NMHC）Usually refers to all volatile hydrocarbons except methane, also known as non methane total hydrocarbons. atmosphericNMHCBeyond a certain concentration, it is harmful to human health and can also produce photochemical smog, posing a threat to the environment and humans.
China's Comprehensive Emission Standards for Air Pollutants（B1627-1996）The boundary concentration standard for non methane total hydrocarbons is5mg/m3According to the fourth edition of the "Air and Waste Gas Monitoring Methods", Kexiao Company adopts a ten way valve for single injection with dual columns in parallelFIDThe optimization plan for the detection process meets the detection requirements of total hydrocarbons and non methane total hydrocarbons, with the lowest detection concentration being0.05mg/m3.

Jiedao IslandGC1690F(S)Characteristics and main technical parameters of non methane total hydrocarbon gas chromatograph:

1.oneFIDConfigure and eliminate doubleFIDDue toFIDThe difference in sensitivity causes errors.

Double packed columns are connected in parallel, and a ten way valve is used for injection to achieve a single injection, while simultaneously analyzing total hydrocarbons and methane.

2.Experimental instruments

GC1690Gas chromatograph (Hangzhou Kexiao Chemical Instrument Equipment Co., Ltd.);

JO-4(Dalian)；

3.Testing process

3.1Sample processing procedure

The sample processing process shall refer to Method 1 of the "Air and Waste Gas Monitoring Methods" (Fourth Edition). use100mlGlass syringe, sealed syringe after on-site sampling.

3.2Chromatographic conditions

Column temperature:50℃
Detector temperature:150℃
Injector temperature:150℃
Injection volume:1ml
Column flow rate:20ml/min

3.3qualitative analysis

When the sample enters the total hydrocarbon analysis column, only one total hydrocarbon peak appears, and other components in the sample cannot be separated; The sample enters the methane analysis column, which can separate methane from other components.

1.4quantitative analysis

Using methane as the standard gas, quantitative analysis was conducted using the area external standard method, and the results were calculated based on methane.

4.experimental result

4.1 System Applicability Test

use5μmol/mol（VN）Methane standard gas was analyzed, and the results are shown in the table1

4.2 Standard Curve

use100mlGlass syringe, high-purity nitrogen diluted step by step method to configure different concentrations:5/10/20/50/100μmol/molMethane standard gas is injected with appropriate amounts of gas standard gas for analysis, and the peak area and corresponding standard gas concentration are used as the standard curve.

According to the above chromatographic conditions, the following standard curve is obtained:

4.3Dehydrogenation air analysis

followO2existFIDThe response has a positive interference on the analysis of total hydrocarbons, and it is necessary to use dehydrogenated air as a blank. The actual total hydrocarbons in the sample need to be deducted from the air

Interference. The analysis of hydrocarbon removal air is shown in Figure 4. The quantitative results are shown in the table2

4.4air sample analysis

use10mlThe glass syringe sucks in the air in the test room, such as gas chromatography for analysis. The spectrum is shown in the figure5,3The repeatability analysis is shown in the table3

Quantitative repeatability taste of total hydrocarbons2.04%The quantitative repeatability of methane is1.74%Meets the requirements of quantitative detection methods. Non methane total hydrocarbons=total hydrocarbon-Air blank-methane=4.60-1.74-2.40=0.45μmol/molapproach0.32/m3

1.conclusion

The method described in this article can meet the testing requirements for total hydrocarbons and non methane total hydrocarbons in the air, which complies with national standards. The lowest detection concentration can reach0.05mg/m3.

Jiedao IslandGC1690F(S)List of configurations for non methane total hydrocarbon gas chromatograph:

1.GC1690F（s） 1tower

2.Ten way valve 1only

3.Stainless steel analytical column 2branch

4.Standard gas（8Rising)10ppm CH4/N2 1bottle

5.pressure reducing valve 752(Standard gas) 1only

6.100mlGlass syringe 10branch

7.10mlGlass syringe 5branch

8.Gas sampling bag(1-2rise) 10only

9.Air hydrocarbon purifierJO-4 1tower

10.Chromatography workstationN2000 1tower

11.computer/printer 1cover

12.High purity nitrogen ≥99.99%(including pressure reducing valve) 1bottle

13.High purity hydrogen generatorSGH-300A 1tower

14.No oil, no water, no noiseWJK-2LB 1tower