This method is applicable to the determination of trace carbon dioxide in electronic grade oxygen, with a determination range of 0.1 to 14.6 ppm. SJ 2803-1987 Method for determination of trace carbon dioxide in electronic grade oxygen Pre-cutting hydrogen flame conversion chromatography SJ2803-1987 Standard download decompression password: www.bzxz.net
This method is applicable to the determination of trace carbon dioxide in electronic grade oxygen, with a determination range of 0.1 to 14.6 ppm.

Standard of the Ministry of Electronic Industry of the People's Republic of China Method for the determination of trace carbon dioxide in electronic grade oxygen Pre-cutting, hydrogen conversion chromatography
SJ2803-87
This method is suitable for the determination of trace carbon dioxide in electronic grade oxygen, and the determination range is 0.1~14.6PPm. 1 Principle of the method
1.1 This method is a 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, many ion pairs are generated due to the ionization reaction. If a pair of electrodes are added to the upper and lower parts of the flame and a certain voltage is applied, the generated ion flow can be detected, thereby determining the organic matter entering the flame.
After the components of the sample are separated by the chromatographic column, they pass through the conversion furnace in turn, where carbon dioxide is converted into methane under the action of nickel catalyst through 1.2
high temperature reaction. The reaction formula is as follows: Guo\c
-CH-+ 2H. 0
In this reaction, carbon dioxide and methane are equimolecular, so the content of carbon dioxide can be directly obtained by measuring the methane content.
1.3 In order to avoid the shortcomings of a large amount of nitrogen entering the converter, affecting the life of the nickel catalyst and blowing out the flame, this method uses a piton pre-cutting device to cut off the large amount of oxygen after the chromatographic column separation. To prevent positive oxygen from entering the converter. 2 Instruments and materials
a. Gas chromatograph with hydrogen initial detector; b. Six-way injection valve with quantitative tube;
E, converter
|t. Pre-cutting device,
t. Index diluter:
f. Recorder or microprocessor: 0~1mV.
Gas source:
Carrier gas: nitrogen, purity of 99.999%, carbon dioxide content less than 0.05PPm; fuel gas: hydrogen, purity of 99.999%, dichloromethane content less than 0.05PPm; combustion gas: air, purified by silica gel or molecular sieve, the content of alkane should be less than 2PPm. h, Chromatographic column: stainless steel tube, inner diameter of 3mm, length of 2m, inner diameter of 3m, length of 1m. Filler: molecular microspheres, GDX-104, 60-80 days. Main, conversion tube: stainless steel tube, containing about 2g of nickel catalyst. Conversion rate is greater than or equal to 95%. bzxz.net
3 Process block diagram and test conditions
3.1 The process block diagram is shown in Figure 1.
Published by the Ministry of Industry on 1987-05-18
Implemented on 1988-01-01
3.2 Test conditions
SJ2803-.87
Datong sampling valve
Four-way switching valve
Calibrator
Recorder
1 Chromatographic column
Grade I chromatographic column
Flow chart for the determination of trace carbon trioxide in electronic grade oxygena. Column temperature: room temperature, 15~35C
b. Gasification temperature: room temperature, 15~35℃; C, detection chamber temperature: 100℃:
d. Cutting valve temperature: 90℃:
e. Converter temperature: 600C.
Carrier gas, nitrogen flow rate 13m1min;
Combustion gas: gas flow rate I, 25m1min;
I.5m1/min;
Combustion gas: air flow rate 5～600m1min. g. Sample injection volume: 2ml.
Operation steps
4.1 Preparation before starting the instrument: Check the tightness of the gas line and the electrical part. Converter
4.2 Start the instrument: Open the nitrogen valve, adjust the flow rate, start the instrument, when the detector humidity rises to 100℃, open the hydrogen and air bottle valves to ventilate, ignite the nitrogen flame detector, adjust the flow rates of the three gases after ignition, and inject the sample for analysis after the recorder baseline is stable.
.3 Standard curve drawing
Use exponential diluter to prepare standard gas (oxygen as the base, carbon dioxide less than 0.05PPm), and then inject it through the six-way injection valve: draw the "standard curve of peak height and concentration of carbon dioxide". See Figure 2.4,4 The sample gas enters through the six-way sampling, and is separated by the I-level separation column. The oxygen and carbon dioxide after separation are cut off by the cutting valve to prevent co-entry into the converter. The cut oxygen and carbon dioxide enter the II-level separation column for further separation, and enter the converter in turn. Carbon dioxide is used as a nickel catalyst, and is hydrogenated to become alkane at high temperature, and then enters the hydrogen flame detector for determination, and its peak height is recorded by the recorder. Repeat twice, the relative partial vaporization does not exceed 10%, and the average peak height is hmm. E Calculation results
According to the methane content and the corresponding peak height value in the standard sample and the peak value of the alkane component in the sample, check the "standard curve of methane peak height and concentration", or calculate the methane component content in the sample according to the following formula. CC stands for·
peak height,
SJ2803-87
Figure 2 Standard curve of carbon dioxide in electrochemical oxygen
Where:
C\—methane concentration of the sample gas to be tested, ppm; C·-methane carbonyl content of the standard sample gas, Ppm; h—methane peak height of the measured sample gas, m:
h------methane peak height of the standard sample gas, mm. The relative standard deviation of the analysis precision
is less than ± 5.
Test report
7.1 The test report should include the following contents:
a. Time, place, unit, month;
b. Sampling place and number;
c. Sample name;
d. Type of instrument used:
e. Test strip and result:
f. Analyst signature.
8 Attention items
8.1 The air tightness of the large-pass injection valve should be checked frequently. 8.2 The injection temperature and pressure of the standard gas and sample should be kept consistent during the measurement. 8.32 The flow rate of the gas must be strictly controlled.
20 Concentration PPm
8.4 The flow rate of the dilution gas must be stable and reliable. 8.5 Protection of the converter:
SJ2803-87
2. Control the maximum cutting time and prevent a large amount of oxygen from entering the converter; b. Pay attention to the conversion rate, which must not be less than 95%, ℃, and the shape of the dioxygen batch must be symmetrical and not rat-dig. See Figure 3.
Typical chromatogram
5mm/min
Additional instructions:
Typical chromatogram of trace carbon dioxide determination in electronic group This standard was proposed by the Clean Technology Society of the Chinese Institute of Electronics and sponsored by the Standardization Institute of the Ministry of Electronics Industry. This standard was drafted and revised by Zhu Guohua of the 742 Factory of the Ministry of Electronics Industry, Zheng Jiyuan of the Institute of Testing Technology, Zhao Changchun of the Standardization Institute of the Ministry of Electronics Industry, and Bang Enhua of the Semiconductor Institute of the Chinese Academy of Sciences. 1
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