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4 Test method
The reagents and water used in the test method, unless other requirements are specified, refer to the analytical reagents and the tertiary water specified in GB/T6682
4.
Determined by visual inspection
4.
According to the provisions of GB/T3143
4.
According to the provisions of GB/T7533
4.
According to the provisions of GB/T6283
Take the arithmetic mean of the two parallel determination results as the determination result
4.
4.
After the liquid sample is vaporized in the gasification chamber, it passes through the chromatographic column to separate the components and detects with a flame ionization detector.
4.
4.
4.
4.
5.
2.
3 Hydrogen : the purity is not less than 99.
9%
.
4.
5.
2.
4 Air: after purification treatment
.
4.
5.
3 Apparatus and equipment
4.
5.
3.
1 Gas chromatograph: equipped with a flame ionization detector, the sensitivity and stability of the gas chromatograph can be used to meet the operating conditions listed in Table A1
.
4.
5.
3.
2 Chromatography workstation or chromatographic data processor
.
4.
5.
3.
3 Micro sampler: 1L
.
4.
5.
4 Chromatographic column and chromatographic operating conditions
The chromatographic column, chromatographic operating conditions, relative retention time and typical chromatogram recommended by this standard and Appendix A (standard appendix)
.
Chromatographic columns and chromatographic operating conditions that can achieve the same degree of separation can be used
.
4.
5.
5 Analysis steps
Weigh 1.
0g sample (accurate to 0.
01g) into a 10mL Erlenmeyer flask with stopper, add 10mL chloroform to dissolve it, and mix it
.
After the instrument is stable, use a micro-injector to inject 1μL of this sample solution.
Measure the peak area of each component, using the area normalization method, calculated by the chromatographic workstation or the chromatographic data processor
.
Note: 1) If the chloroform reagent contains interfering impurities, it should be deducted from the background
.
4.
5.
6 Expression of analysis results
The content of diphenyl ether w 1 and the content of phenol w 2 expressed in mass fraction are calculated according to formula (1) and formula (2):
In the formula: A 1 , A 2 , A i -are the peak areas of diphenyl ether, phenol and component i, respectively;
∑A i — the sum of the peak areas of all components
.
Take the arithmetic mean of the two parallel determination results as the determination result
.
The difference between the two parallel determination results shall not be more than 0.
05%
.
4.
6 Determination of total chlorine content
4.
6.
1 Method summary
After the sample vaporizes in the preheating zone of the combustion tube, it enters the combustion zone with the carrier gas and mixes with oxygen and burns, so that the organochlorine in the sample is converted into chlorine ions, and then the carrier gas is brought into the titration cell to react with silver ions, causing The silver ion concentration decreases, the measurement-reference electrode pair indicates the change of the silver ion concentration, and the signal is sent to the micro-coulomb amplifier.
The micro-coulomb amplifier outputs the corresponding current to the electrolysis electrode pair.
The silver ion is generated at the electrolysis anode to make the silver ion in the titration cell.
Concentration restoration, by measuring the amount of electricity required to replenish silver ions, calculate the chlorine content in the sample according to Faraday's law of electrolysis
.
4.
6.
2 Apparatus and equipment
4.
6.
2.
1 Microcoulometer: all instruments that can meet the analysis requirements of this standard can be used
.
4.
6.
2.
2 Recorder
.
4.
6.
2.
3 Micro-injector: 10uL
.
4.
6.
3 Reagents and materials
4.
6.
3.
1 Electrolyte: mix 700 mL of glacial acetic acid with 300 mL of oxygen-free water or double distilled water, and store it in a closed glass bottle with stopper for later use
.
4.
6.
3.
2 Carrier gas: nitrogen with a purity of not less than 99.
9%
.
4.
6.
3.
3 Reactive gas: oxygen, with a purity of not less than 99.
9%
.
4.
6.
3.
4 Organochlorine standard solution:
Weigh an appropriate amount of chlorobenzene (accurate to 0.
0002g), place it in a 100mL volumetric flask, dissolve it with toluene and dilute to the mark, shake well and mix well, and set aside
.
The concentration c 1 (g/mL) of the organic chlorine standard solution is calculated according to formula (3):
In the formula: m 1 -the mass of chlorobenzene, in grams (g);
0.
3156—The ratio of the international relative atomic mass of chlorine to the relative molecular mass of chlorobenzene;
100—The volume of the organic chlorine standard solution, in milliliters (mL)
.
The standard solution should be diluted to a concentration close to that of the analytical sample when in use.
Except for the organic chlorine standard solution with a content of less than 10ug/mL that needs to be prepared before use, it can generally be stored for two months
.