GB/T 3393-1993 Determination of trace hydrogen in industrial ethylene and propylene by gas chromatography

This standard specifies the gas chromatography method for the determination of hydrogen content in industrial ethylene and propylene. This standard is applicable to the determination of hydrogen with a concentration greater than 1 m/m3 in ethylene and propylene. GB/T 3393-1993 Determination of trace hydrogen in industrial ethylene and propylene by gas chromatography GB/T3393-1993 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of trace of hydrogen in ethylene and propylene for industrial use - Gas chromatographic method
1 Content and scope of application
This standard specifies the gas chromatographic method for the determination of hydrogen content in ethylene and propylene for industrial use. This standard is applicable to the determination of hydrogen with a concentration greater than 1m/m in ethylene and propylene. 2 Reference standards
GB/T13289 Sampling method for liquid and gaseous ethylene for industrial use GB/T13290 Sampling method for liquid and gaseous propylene and diene for industrial use 3 Summary of the method
GB/T3393-93
Replaces GB/T3393-82
The gas sample is injected through the sampling device and carried into the chromatographic column by the carrier gas to separate hydrogen from other components and then detected by a thermal conductivity detector, and its chromatographic analysis is recorded. Calculate the hydrogen component content by external standard method. 4 Materials and reagents
4.1 Carrier gas
Chlorine: purity greater than 99.99%. Dry and purify with silica gel and 5A sieve. 4.2 Ethylene: purity greater than 99%, it does not contain hydrogen. 5 Instrument
It is a gas chromatograph equipped with a thermal conductivity cell detector and a backflush device. The peak height of hydrogen produced by the instrument at the minimum detection concentration specified in this standard should be greater than twice the noise. 5.1 Injection system
Gas injection valve. Fixed tube volume 1~3 mL. 5.2 Chromatographic column
The recommended chromatographic column and typical operating parts are shown in Table 1. Other chromatographic columns that can achieve the same separation efficiency can also be used. 5.3 Detector
Thermal conductivity cell detector,
5.4 Recording device
Recorder, integrator or chromatographic data processor Approved by the State Administration of Technical Supervision on July 21, 1993 and implemented on July 1, 1994
Color Harmony Society
Tube material
Inner diameter, nm
Fixed particle size, mm
Gas flow rate, ml./nvin
Injection sensitivity + mL
GB/T 339393
Recommended chromatographic column and typical operating conditions Carbon molecular sieve
TDX-01
0, 149--0.177bzxZ.net
Organic carrier 40713
3mL or selected by the user, should be able to detect 1mL/m hydrogen Note: 1) Purapak has been used Qs can get the best separation effect. 6 Sampling
Take samples according to the technical requirements of GH/T13289 and GB/T13290. 7 Operation steps
7, 1 Setting the operating conditions
After the chromatograph is started, make necessary adjustments to achieve the typical operating conditions listed in Table 1 or other suitable conditions that can obtain equal separation. After the instrument is stable, it can be measured. 7.2 Preparation of standard samples
This standard uses the external standard method for quantitative analysis. Prepare a standard gas sample with a hydrogen content roughly equivalent to that in the sample in high-purity ethylene or pure nitrogen (no hydrogen should be present).
7.3 Measurement
7. 3. 1 Calibration
Use the gas inlet valve to inject 1 to 3 mL of standard gas sample into the chromatograph under the specified conditions. Repeat the measurement twice. After the components are separated, measure the peak area or peak height of nitrogen as the quantitative calculation standard. 7.3-2 Sample determination
Take a sample of the same volume as the standard gas sample and inject it into the chromatograph through the gas injection valve. Repeat the determination twice, record and measure the peak area or peak height of hydrogen, and compare it with the external standard. 7.3.3 Typical chromatogram
Typical chromatograms are shown in Figures 1 and 2. The nitrogen concentration X in ethylene and propylene is calculated as follows: X, = E. .
or X, = E·light
Chlorine content in sample, mL/m
E Hydrogen content in standard gas sample, mL/m;
The peak area of ​​hydrogen in sample;
Ae The peak area of ​​ammonia in standard gas sample,
H:---The peak area of ​​hydrogen in sample;
The peak height of hydrogen in standard gas sample.
GB/T 3393-93
Figure 1 Typical chromatogram of carbon molecular sieve
Hydrogen: 2-oxygen: 3-methane
4mm/min
Figure 2 Typical chromatogram of organic support 407
1 Hydrogen; 2 Oxygen: 3-methane + 4 Ethylene
8 Expression of results
8.1 Analysis results
The arithmetic mean of two repeated measurements shall be taken as the analysis result, and the unit shall be volume per cubic meter of product (ml.). 8.2 Precision
8.2.1 Repeatability
The same operator uses the same instrument, under the same operating conditions, to perform two repeated measurements on the sample using normal and correct operating methods. Within the range of hydrogen concentration of 5 to 20mL/m2, the difference between the measured values ​​shall not be greater than 10% (9.5% reference water) of the arithmetic mean of the two measured values.
8.2.2 Reproducibility
GB/T3393-93
In any two different laboratories, by different operators, using different instruments and equipment, at different or the same time, the difference between the two single measurement results of the same sample for a hydrogen content of 5~20mL/m should not be greater than 30% of the arithmetic mean (95% confidence level).
9 Test report
The report should include the following:
All information about the sample: batch number, date, time, sampling location, etc. a.
Measurement results
Abnormal phenomena observed in the test;
Description of any operation and freely selected operating conditions not included in this standard. Additional notes:
This standard was proposed by China Petrochemical Corporation. This standard is under the jurisdiction of the Petrochemical Standardization Technical Committee. This standard was drafted by Shanghai Petrochemical Research Institute. The main drafters of this standard are Tang Qimin and Fang Zhide.
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