This method is applicable to the determination of trace carbon monoxide in electronic grade hydrogen, nitrogen, oxygen, argon and helium, with a determination range of 0.5 to 20 ppm. SJ 2801-1987 Method for determination of trace carbon monoxide in electronic grade gases Pre-cut hydrogen flame conversion chromatography SJ2801-1987 Standard download decompression password: www.bzxz.net
This method is applicable to the determination of trace carbon monoxide in electronic grade hydrogen, nitrogen, oxygen, argon and helium, with a determination range of 0.5 to 20 ppm.

Standard of the Ministry of Electronic Industry of the People's Republic of China on the determination of trace carbon monoxide in electronic-grade gas Pre-cutting, hydrogen flame conversion chromatography
SJ2801--87
This method is suitable for the determination of trace carbon monoxide in electronic-grade hydrogen, nitrogen, oxygen, nitrogen and ammonia, with a determination range of 0.05-20ppm.
1 Principle of the method
1.1 This method is pre-cutting hydrogen flame conversion chromatography. The hydrogen flame detector uses the flame generated by the combustion of hydrogen and air as energy. When organic matter enters the flame, ion pairs are generated due to the ionization reaction. If a pair of electrodes are added to the flame and a certain voltage is applied, the generated ion flow can be detected, thereby determining the organic matter entering the flame.
1.2 After the components of the sample are separated by the chromatographic column, they pass through the converter in turn, so that the carbon monoxide in it is converted into methane through a high-temperature hydrogenation reaction under the action of the nickel catalyst. The reaction formula is as follows: 600℃
CO+3H2
CH4+H20
In the reaction, carbon monoxide and methane are equimolecular, so the content of carbon monoxide can be directly obtained by measuring the methane content.
1.3 In order to avoid the shortcomings of a large amount of oxygen entering the converter, affecting the life of the nickel catalyst, blowing out the flame, etc., this method uses a four-way pre-cutting device to cut off a large amount of oxygen after the chromatographic column is separated to prevent oxygen from entering the converter. 2 Instruments and materials
Gas chromatograph with hydrogen flame detector:
b: Six-way injection valve with quantitative tube:
Converter;
d. Pre-cutting device;
Exponential diluter:
f, recorder or microprocessor, 0~1my. g. Gas source
Carrier gas: nitrogen, purity is 99.999%, of which the carbon dioxide content is less than 0.05ppm. Fuel gas: hydrogen, purity is 99.999%, of which carbon dioxide content is less than 0.05ppm. Fuel-supporting gas: air, purified by silica gel or molecular sieve, flow rate is 550~600ml/min. h, Chromatographic column: stainless steel tube, inner diameter 3mmx2m. Filler: 60-80 mesh 5A molecular sieve.
i, Conversion tube: stainless steel tube contains about 2g of nickel catalyst, conversion rate is greater than or equal to 95%, 3 Flow chart and test conditions
3.1 The flow chart is shown in Figure 1.
Promulgated by the Ministry of Electronics Industry on May 18, 1987
Implemented on January 1, 1988
The flow chart is shown in Figure 1
Converter
SJ2801-87
Six-way sampling valve
Calibrator
Chromatographic column
Recorder
Figure 1a Flow chart for determination of trace carbon monoxide in nitrogen, nitrogen and nitrogen carrier gas
Test conditions
Pre-cutting valve
Recorder||t t||Six-way valve
Converter
Chromatographic column
Flow chart of trace carbon monoxide determination in Figure 1b
Tester
Flow chart of trace carbon monoxide determination in electronic grade hydrogen, nitrogen, ammonia, nitrogen Column temperature: room temperature
15~35℃
b..Gasification temperature: room temperature 15~35℃;
Detection chamber temperature: 100℃;
d. Cutting valve temperature: 90℃;
e. Converter temperature: 600a.
f: Gas source
Carrier gas: Nitrogen flow rate is 50ml/min;
Combustion gas: Hydrogen flow rate is 50ml/min:
Combustion gas: Air flow rate is 500ml/min. g. Sample injection volume: 5ml.
Operation steps
4.1 Preparation before starting the instrument: Check the air tightness of the gas circuit and the electrical part. 4.2 Start the instrument: Open the nitrogen valve, adjust the flow rate, and start the instrument. When the temperature of the detector rises to 100℃, open the valves of the hydrogen and air bottles for ventilation, ignite the hydrogen flame detector, and adjust the flow rates of the three gases after ignition. After the recorder baseline is stable, analysis can be carried out.
4.3 Drawing of standard curve: Use exponential diluter to prepare standard gas (the base gas is oxygen, in which carbon dioxide is less than 0.05Ppm), and then inject it through a six-way injection valve; draw the "peak height and concentration standard curve of carbon monoxide", see Figure 2 for details. 2
SJ2801-87
Standard curve of carbon monoxide in electronic grade hydrogen
Standard curve of carbon monoxide in electronic grade nitrogen
Concentration PP
SJ2801-87
Standard curve of carbon monoxide in electronic grade oxygen|| tt||Figure 2d Standard curve of carbon nitride in electronic grade fluorine 10
Concentration PPm
10Concentration PPm.
Figure 2 Standard curve for determination of trace carbon monoxide in electronic grade hydrogen, nitrogen, oxygen and argon 4.4 The sample gas enters through the six-way sampling valve, and the small amount of oxygen and carbon monoxide after cutting enter the second-level separation column for separation, and then enters the converter in turn. Carbon monoxide reacts with hydrogen under the action of nickel catalyst to become methane, and then enters the hydrogen flame detector for determination, and its peak height is recorded. 4
SJ2801-87
Repeat three times, and the relative deviation does not exceed 10%, and the average peak height hmm is taken. 5 Calculation results
According to the carbon monoxide content in the standard sample and the corresponding peak height value and the peak height value of the carbon monoxide component in the sample, the "carbon monoxide peak height and concentration standard curve" is set, or the carbon monoxide component content in the sample is calculated according to the following formula. C sample = C divided by ·
Where:
C sample - carbon monoxide concentration of the sample gas to be tested, PPmC standard sample gas carbon monoxide concentration, Ppm; h sample: carbon monoxide peak height of the sample gas to be tested, mm; h standard - carbon monoxide peak height of the standard sample gas, mm. 6 Analytical precision
Relative standard deviation is less than ±5%.
Test report
The test report should include the following:
Time, place, unit, date;
Sampling place and number:
Sample name;
Type and model of instrument used:
Test conditions and results;
Signature of analyst.
Precautions
The air tightness of the six-way injection valve should be checked frequently. The injection temperature and pressure of the standard gas and sample gas should be kept consistent during the measurement. The gas flow rate must be strictly controlled.
The dilution gas flow rate must be stable and reliable. 8.5
Protection of the converter:
Control the optimal cutting time and prevent a large amount of oxygen from entering the converter; b.
Note that the conversion rate change must not be less than 95%;www.bzxz.net
The carbon monoxide peak shape must be symmetrical and cannot be tailed. c.
9 Typical chromatograms are shown in Figure 3
5mm/min
SJ2801-87
5mm/min
Chromatogram of carbon monoxide in hydrogen
5mm/min
Figure 3b Chromatogram of carbon monoxide in nitrogen
Additional notes
5mm/min
Chromatogram of carbon monoxide in oxygen
Figure 3d Chromatogram of carbon monoxide in argon
Typical chromatograms for the determination of trace carbon monoxide in electronic grade hydrogen, nitrogen, oxygen and argon This standard was proposed by the Clean Technology Society of the Chinese Institute of Electronics. It is sponsored by the Standardization Institute of the Ministry of Electronics Industry. This standard was drafted and revised by Zou Jingsun of the Tenth Design Institute of the Ministry of Electronics Industry, Zhao Changchun of the Standardization Institute of the Ministry of Electronics Industry and Yin Enhua of the Institute of Semiconductors of the Chinese Academy of Sciences. 6
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