This method is applicable to the determination of trace oxygen and argon in electronic grade hydrogen, with a minimum detection amount of 0.01ppm. SJ 2806-1987 Determination of trace oxygen and nitrogen in electronic grade hydrogen - Variable temperature concentration chromatography SJ2806-1987 Standard download decompression password: www.bzxz.net
This method is applicable to the determination of trace oxygen and argon in electronic grade hydrogen, with a minimum detection amount of 0.01ppm.

The standard of the Ministry of Electronic Industry of the People's Republic of China for the determination of trace oxygen and nitrogen in electronic grade hydrogen is variable temperature concentration chromatography
SJ2806-87
This method is suitable for the determination of trace oxygen and nitrogen in electronic grade hydrogen, and the minimum measurement is 0.01PP. 1 Principle of the method
1.1 This method is a variable temperature concentration chromatography. The carrier gas carries the sample through the chromatographic column to separate the components, and then enters the thermal conductivity detector.
1.2 The thermal conductivity detector is made based on the principle that the thermal conductivity of other components mixed in the carrier gas changes. When the sample and the carrier gas enter the thermal conductivity cell together, due to the different thermal conductivities of the two, the temperature of the thermistor changes, causing its resistance to change accordingly, and the output signal is measured by the Wheatstone bridge.
1.3 In order to improve the sensitivity, this method adopts the concentration technique, that is, under low temperature conditions, the impurities are enriched on the concentrator to increase the injection volume. When the temperature is -196℃, the molecular sieve has a good adsorption capacity for nitrogen, hydrogen, etc. 1.4 Chromatographic analysis with hydrogen as the cutter. Www.bzxZ.net
1.5 In order to achieve the analysis of carrier and fluorine separately, the method uses two chromatographic columns in combination, and first separates oxygen, ammonia and nitrogen in one column, and then uses palladium catalyst to remove the gas, and then separates nitrogen and nitrogen. 2 Instruments and materials
2.1 Gas chromatograph
a. Thermal conductivity detector
b. Chromatographic column: stainless tube with an inner diameter of 4mm and a length of 1.5~3ml; carrier is 5A molecular sieve 60~80 c. Recorder or microprocessor: 0~1mV: 2.2 Carrier gas: hydrogen-free material or ultra-pure fluorine. 2.3 Sampler: glass or metal tube with 40~60 mesh polymer microspheres 2~4g, both ends are blocked with high-purity quartz cloth.
2.4 Gas flow meter
2.5 Cold source: liquid nitrogen
2.6 Catalyst 0.5~1g is put into a stainless steel tube with a true diameter of about 1,5mm×10cm: 3 Process flow chart and test conditions
3.1 See Figure 1 for the process flow chart.
Palladium catalyst
Recorder
Released by the Ministry of Electronic Industry on May 18, 1987
Color discrimination column I
Chromatographic column
Flow chart for determination of oxygen and amount in electronic grade hydrogen
Calibrator
Implemented on January 1, 1988
3.2 Test conditions:
Bridge current: 180～200mA
SJ2806--87
Carrier gas flow rate, 40～６0m1／min
Paper speed: 5mm/min;
Attenuation: 1;
Detection temperature: room temperature, 15~35℃.
4 Operation steps:
High-purity microsphere
Wet concentration sampling device
A: Sample gas cylinder
: Needle valve
C: Four-way piston concentration sampling tube
D: Source
E: Wet gas flowmeter
Four-way piston concentration sampling tube
SJ2806-B7
4.1 Purge gas path According to Figure 2, hard-connect or ground-joint connection system, the concentration tube is closed. Open the gas valve, flow about 1000m1/mi, time 0.5h. Reduce the flow rate to 800m1/min, open the four-way piston (see Figure 3), and allow the hydrogen to pass through the adsorbent in the sampler to purge the air therein for half an hour, and further adjust the flow rate to 800m1/min. 4.2 Sampling: Slowly put on the cold source and start counting the time. When the diffuse gas flowmeter indicates that the gas volume has reached the requirement, turn off the gas source: remove the cold source at the same time, and when the gas discharged from the release tube is about 100mL/min, close the piston and put down the sample tube. 4.3 Sampling Desorb the concentrator tube in room temperature water or a hair dryer for 3 to 5 minutes, connect the concentrator tube to the chromatograph injection port with a hard connection, exhaust the air peak first, open the four-way piston of the concentrator tube for sampling, wait for the sample peak to be completed, and use a micro-plate injector to inject air as a standard sample.
5 Calculation results
The content of oxygen in hydrogen
The content of air in hydrogen
XV ×21,88%×
X,X0.93%X
Oxygen content in hydrogen = ×20.95%V×（
Assume air standard volume V1: μl,
air standard sample oxygen + argon peak area A2, mm2 peak area A, mm sample volume V, μl,
sample oxygen + fluorine peak area A, mm2 argon peak area A, mm2: 93% constant is the percentage content in air:
21,88%×
X,X0.93%X
Oxygen content in hydrogen = ×20.95%V×（
Assume air standard volume V1: μl,
air standard sample oxygen + fluorine peak area A, mm2 argon peak area A, mm2: 93% constant is the percentage content in air:
21,88% 8% constant is the percentage of oxygen in the air, 6 Analytical precision
The arithmetic mean of three parallel determinations is the determination result, and the relative deviation is not more than ±15%. 7 Test report
7.1 The test report should include the following contents:
a. Time, place, unit, date: b. Sampling method and number:
c. Type and model of instrument used:
d. Test conditions and results;
package. 3 Analyst signature.
8 Precautions
8.1 The chromatographic column must be well activated. The activation condition is to pass hydrogen. The gas flow rate is 50m1/min, at about 200, and the activation time is 12h.
8.2 The absorbent in the sampling tube should be activated. The activation conditions are nitrogen, the flow rate is 60m1/min, at about 180, and the activation time is 8h, until there is no moisture on the tube wall. 8.3 The cylinder must be adjusted with a needle valve, otherwise the dead volume will be large and the gas path will not be easy to purge clean. 3
SJ2806-87
8.4 The system must be hard-connected to prevent gas. The ground mouth and the four-element piston must be sealed with grease such as silicone grease and fit tightly. 9 See Figure 4 for a typical chromatogram.
Oa + Ar
Note:
5mm/min
Typical color chart for determination of trace oxygen and fluorine in electronic grade fluorine This standard was proposed by the China Institute of Electronics and Technology and hosted by the Standardization Institute of the Ministry of Electronics Industry. This standard was drafted and revised by Sheng Ganhua, Yang Xuezhen of the Institute of Semiconductors, Chinese Academy of Sciences and Comrade Zhao Changchun of the Standardization Institute of the Ministry of Electronics Industry.
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