SJ 3238-1989 Determination of trace nitrogen in electronic grade argon Argon ionization gas chromatography SJ3238-1989 standard download decompression password: www.bzxz.net

Standard of the Ministry of Machinery and Electronics Industry of the People's Republic of China Method for the determination of trace nitrogen in electronic grade argon
Argon ionization gas chromatography
1 Subject content and scope of application
1.1 Subject content
This standard specifies the argon ionization gas chromatography analysis method for trace nitrogen in electronic grade argon. 1.2 Scope of application
SJ3238--89
This standard applies to the determination of trace nitrogen in electronic grade argon. When the injection volume is 3ml, the determination range is 2~60ppm
2 Principle of the method
2.1 This method is an ionization detector gas chromatography method using high-purity argon as the carrier gas. 2.2 The nitrogen in the analyzed gas is separated from other impurities by a molecular sieve chromatographic column and then enters the argon ionization detector. 2.3 Argon ionization detector uses fluorine source as energy source. The β particles radiated by fluorine source excite hydrogen molecules to generate metastable argon. Metastable argon atoms with a certain energy ionize organic vapor molecules with lower excitation energy than argon to generate base flow. When impurity molecules enter the ionization chamber, a quenching effect occurs, causing the base flow to decrease. Under certain conditions, the base flow drop value is proportional to the impurity concentration, so the impurity content can be measured. 3 Instruments and materials
Ammonia ionization gas chromatograph;
Exponential diluter;
Gas purifier with 1015 mesh zirconium aluminum 16 getter injection valve;
Chromatographic column stainless steel tube, inner diameter 2mm, length 1~2m, filled with 30-60 mesh 5A or 13X molecular f.
Recorder 01mV, or microprocessor;
Pure argon meets GB4842;
h, organic gas source stainless steel tube inner diameter 2mm, length 15cm, filled with pure trichlorobenzene. 4 Determination flow chart and test conditions
4.1 Flow chart, see Figure 1.
Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on March 20, 1989 and implemented on March 25, 1989
Pure oxygen purifier
Test conditions
Exponential dilution
Factory standard gas
SJ3238-89
Six-way injection valve
Dilution standard gas
Color harmonic sample
High voltage
Figure 1 Flow chart of oxygen ionization gas chromatography
Column chamber temperature (13~33℃);
Detector temperature|| tt||Purification furnace temperature
Detector high voltage
Collection stage high resistance
Room temperature (15~35℃)
First level purification 700℃; Second level purification 400℃; 250~500V;
10°2;
Carrier gas flow rate 40ml/min;
Dilution gas flow rate 60ml/min;
Standard gas sample volume
Sample gas injection volume 3ml,
5 Operation steps
Before starting the instrument, strictly check the sealing of the gas path. Detector
Excitation current amplifier
Recording instrument
5.2 Turn on the purification furnace heating switch, connect the host, micro-current amplifier and high-voltage power supply; after the purification furnace temperature reaches the set value, turn the organic gas valve to make the carrier gas flow through trichlorobenzene and then enter the detector, and adjust the carrier gas flow rate. Turn on the recorder and start the test after the baseline is stable. 5.3 Standard: Adjust the dilution gas flow rate to the set value and turn on the diluter switch. Inject 0.1ml of air. Then inject 1ml of diluted standard gas through the injection valve every 3 minutes. 5.4 The sample gas test is injected through the six-way valve, and the peak height and retention time are recorded. Repeat three times. 6 Result calculation
6.1 Standard calculation
a. The initial concentration Co of the diluted standard gas nitrogen is calculated according to formula (1) C-Cm x
SJ3238—89
Where: C. is the initial concentration of the diluted standard gas, ppm; the nitrogen concentration in the air is 78%;
V, the volume of the injected air, ml; wwW.bzxz.Net
is the volume of the dilution bottle, ml.
b. The average dilution factor is calculated according to formula (2):
wherein: n is the number of times the diluted standard gas is injected;
h is the height of the nitrogen at the i-th injection, mm; the concentration of nitrogen in each injection of standard gas, C, is calculated according to formula (3): c.
wherein: C- is the nitrogen concentration in the standard gas, ppm; d. The response coefficient F is ppm/mm,
e. The standard curve is drawn with h as the vertical axis and C as the horizontal axis. The reciprocal of the slope is the F value. See Figure 2.
Figure 2 Standard curve
6.2 The nitrogen concentration C in the sample gas is calculated according to formula (4): 20
SJ3238-89
Wherein: Csample is the nitrogen concentration in the sample gas, Ppm; hsample is the peak height of nitrogen in the sample gas, mm;
Vmark is the standard gas injection volume, ml;
- is the sample gas injection volume, ml.
Note: The calculation formula is derived from Appendix A of SJ3237--89. 7 Analysis precision
The relative average deviation of the three analysis results is less than 15%. 8 Test report
8.1 The test report should include the following contents:
Time, place, unit, date;
Sampling method and number;
Sample name;
Type and model of instrument used;
Test conditions and results;
Any abnormal phenomenon observed during the measurement; Analyst's signature.
Precautions
The fluorine source of the detector must always have hydrogen passing through it, and the gas system must be hard-connected. Before use, the air tightness of each part must be strictly checked. 9.2
9.3 The carrier gas flow rate must be stable and consistent in a test. 9.4 The dilution gas flow rate must be constant at the set value. 9.5 The standard gas line and sample gas line must be fully purged before injection until there is no injection blank. 9.6 After the analysis is completed, turn off the organic gas.
10 See Figure 3 for a typical chromatogram.
Additional Notes:
SJ3238-89
3 Typical chromatogram for analysis of impurities in electronic grade argon gas Figure 3
This standard was proposed by the Electronic Standardization Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by the Beijing Nonferrous Metals Research Institute. The main drafters of this standard were Cui Xizhong, Zhou Shaolian, Zhao Changchun and Yin Enhua, 5
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