This method is applicable to the determination of trace carbon dioxide in electronic grade hydrogen, nitrogen and argon, with a determination range of 0.05 to 16 ppm. SJ 2802-1987 Determination of trace carbon dioxide in electronic grade gases Hydrogen flame conversion chromatography SJ2802-1987 Standard download decompression password: www.bzxz.net
This method is applicable to the determination of trace carbon dioxide in electronic grade hydrogen, nitrogen and argon, with a determination range of 0.05 to 16 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 gases Hydrogen flame conversion chromatography
SJ2802-87
This method is suitable for the determination of trace carbon dioxide in electronic-grade hydrogen, nitrogen, and argon, with a determination range of 0.05-16PPm1 Principle of the method
1.1 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 ion reactions. 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 quantitatively determining the organic matter entering the flame. 1.2 Hydrogen flame detection has a high sensitivity to carbon-containing organic substances, but has no response to inorganic substances. Therefore, the components of the sample separated by the chromatographic column first pass through the converter in turn, where carbon dioxide is converted into methane through a high-temperature hydrogenation reaction under the action of a nickel catalyst. The reaction is as follows:
CO=+4Hz
600℃
CII4-f2H20
In this reaction, carbon dioxide and methane are equimolecular, so the content of carbon dioxide can be directly obtained by measuring the methane content.
Instruments and materials
a. Gas chromatograph with hydrogen flame detector; b. Six-way injection valve with quantitative tube;
c. Converter
d. Index diluter:
Recorder or microprocessor, 0～1m.
f. Xenon source
Carrier gas, nitrogen, purity is 99.999%, of which the carbon dioxide content is less than 0.02PPm. Fuel gas: hydrogen, purity is 99.999%, of which the carbon dioxide content is less than 0.02PPm. Magnetic assisting gas: air, purified by silica gel or sieve, the alkane concentration should be less than 2PPm. g. Chromatographic column: stainless steel arm, inner diameter 3mm×2m, filler: polymer microsphere, GDX--104, 60-80 mesh. h. Conversion tube: stainless steel tube, filled with 2 nickel tentacles: conversion rate is greater than or equal to 95%.
3 Flow chart and test conditions
3.1 Flow chart see Figure 1
Six-shift valve
Converter
Recorder
Network detector
Color slide
Flow chart for determination of trace carbon dioxide in electronic grade hydrogen, nitrogen and argon Issued by the Ministry of Industry on May 18, 1988
Implemented on January 1, 1988
3.2 Test conditions
Temperature: room temperature, 15~35℃;
b. Gasification temperature: normal, 15-35℃:
Detection case temperature, 100℃
d, converter temperature, 600℃t
e, gas source
Carrier gas: nitrogen flow rate 13ml/min;
Combustion gas oxygen flow rate 25ml/min:
$12802-87
Auxiliary gas: flow rate 550600ml/min;
f: Sample injection grip: 2ml.
4 Operation steps
4, 1 Preparation before starting the instrument, check the air path sealing: check the electrical part. 4.2 Instrument startup Open the nitrogen valve, adjust the flow rate, and start the instrument. When the detector temperature rises to 100C, open the hydrogen and air bottle valves for ventilation, and ignite the flame detector. After ignition, adjust the flow rates of the three gases. After the recorder baseline is stable, you can avoid sample analysis.
Use exponential diluter to prepare standard push gas through quantitative sampling: make * carbon dioxide peak height 4.3 standard curve draw
and concentration standard curve". See Figure 2 for details.
5 concentration PPm
Figure 2a Standard curve of carbon dioxide in hydrogen
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16 liquid PPm,
Standard curve of carbon dioxide in ammonia
Figure 2℃
Standard curve of carbon dioxide in chlorine
degree PPm
SJ2802-$ 7
The sample gas to be measured enters through the six sampling valves, is separated by the chromatographic column, and then enters the converter. Carbon dioxide is hydrogenated at high temperature to generate methane under the action of nickel 4.4
catalyst, and then enters the hydrogen flame detector for determination, and its peak height is recorded by the recorder. Repeat this process for 10 times, and the relative deviation does not exceed 10%. Take the average peak distance hmm. 5 Calculation results
According to the methane content in the standard sample and the corresponding peak height value and the peak height value of the methane component in the sample, check the "methane peak height and concentration standard" or calculate the methane component content in the sample according to the following formula. h
C sample one standard ·
In the formula:
C——methane concentration of the sample gas to be tested, PPm: C—methane concentration of the standard sample gas, PPm; h sample—methane peak height of the sample gas to be tested, m ㎡ 1h standard sample gas methane peak height, mm
B Analytical precision
Relative standard deviation is less than ±5%.
Test report
T.1 The test report should include the following contents
, time, place, unit, date:
b, sampling place and method,
C. Sample name:
d. Type and model of instrument used;
e. Test conditions and results:
f. Name of the analyst.
8 Precautions
B.1 Check the air tightness of the six-way injection valve regularly. 8.2 The injection temperature and pressure of the standard gas and sample gas must be kept consistent during the measurement. 8.3 The gas flow rate must be strictly controlled.
8.4 The dilution gas flow rate must be stable and reliable. 8.5 Protection of the converter:
a. The injection conversion rate should not be less than 95%; b. The peak shape of carbon dioxide must be symmetrical and cannot be tailed. 9 Typical chromatograms are shown in Figure 3.
SJ2802-87
5mm/min
ArCoCH4
smm/mia
Figure 3a Hydrogen-methane, carbon dinitride Figure 3b Nitrogen-\ nitride magnetic separation diagram
Trioxide magnetic separation diagram www.bzxz.net
Gate 3c Argon-dioxide magnetic separation diagram
Separation diagram
Figure 3 Typical chromatograms for determination of trace carbon dioxide in hydrogen, nitrogen and nitrogen at electric grade Additional notes:
This standard was proposed by the China Electronics Society and sponsored by the Standardization Institute of the Ministry of Electronics Industry. This standard was drafted and revised by Zhu Guohua of the 742th Factory of the Ministry of Electronics Industry, the upstream testing technology institute, the Standardization Institute of the Ministry of Electronics Industry, and the Institute of Conductors of the Chinese Academy of Sciences.
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