Industrial cyclohexylamine (2)

4 sampling

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5 Test method

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Observe visually

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The cyclohexamine sample passes through the chromatographic column to separate it from the impurities, and is detected by a flame ionization detector and quantified by the normalization method

5.

a) Gas chromatograph: Sensitivity and stability meet the requirements of GB/T9722;

b) Chromatographic column: a stainless steel column with an inner diameter of 3mm and a length of 2m;

c) Detector: flame ionization detector;

d) Recorder: chromatographic data processor;

e) Sampler: 1L micro syringe

5.

a) Fixing solution: sodium dodecylbenzene sulfonate ;

b) Carrier: White 101 silanized carrier, particle size 149um～177um (100 mesh～80 mesh), pretreated with 1% potassium hydroxide ;

c) Coating degree: fixative/carrier=5/100

d) Staining of fixing fluid:

Weigh 0.
08g of potassium hydroxide into a 250mL beaker, add 25mL of methanol to dissolve it, slowly pour 8.
0g of dry carrier into the beaker, so that the carrier is completely infiltrated, soak for 15min and then heat under an infrared lamp, gently tap and rotate The beaker makes the coating uniform, and after the solvent evaporates to dryness, it is dried in an oven at 100°C for about 30 minutes
.

Weigh 0.
40g of sodium dodecylbenzene sulfonate in a 250mL beaker, add 25mL of chloroform to dissolve it, slowly pour the treated carrier into the beaker to completely infiltrate, and after soaking for 30min, heat it under an infrared light.
Tap and rotate the beaker to make the coating evenly.
After the solvent evaporates to dryness, dry it in an oven at 100°C for 30 minutes
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e) Filling method:

Wrap one end of the chromatographic column connected to the detector with gauze, connect the vacuum pump, and connect the other end to a funnel, and slowly pour the freshly dried stationary phase under vacuum to make the chromatographic column packed evenly and tightly (packed column volume is about 6g) , Put glass wool on both ends of the filled chromatographic column and prepare for aging
.

f) Aging of chromatographic column:

Load the filled chromatographic column into the column box of the chromatograph, and age it for 8 hours at a nitrogen flow rate of about 10 mL/min and a column box temperature of 160°C.
The column should be disconnected from the detector during aging
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5.
3.
4 The determination of the correction factor is shown in Appendix A (standard appendix)
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5 Chromatographic operating conditions

See appendix B (reminder appendix)
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5.
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6 Analysis steps

Start the instrument, after the various operating conditions are stable, draw 0.
4uL sample into the sample, after the peak is completed, the mass percentage of component i is calculated by the following formula
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In the formula: X _i -the content of component i, %;

r _i —the attenuation multiple of the peak area of ​​component i;

f _i —the correction factor of component i, mg/mm2;

A _i —the peak area of ​​component i, mm²;

w—The percentage of moisture content measured according to 5.
4
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Take the arithmetic average of the two parallel determination results as the determination result, and the difference between the two parallel determination results of cyclohexylamine is not more than 0.
2%
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5.
4 Determination of moisture

5.
4.
1 Karl Fischer method (arbitration method) is used for moisture determination in accordance with the method of GB/T6283
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Take the arithmetic mean of the two parallel determination results as the determination result, and the difference between the two parallel determination results shall not exceed 0.
05%
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5.
4.
2 Chromatography

See appendix C (reminder appendix)
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6 Marking, packaging, transportation and storage

6.
1 The cyclohexylamine packaging container should have an obvious mark indicating: manufacturer name, factory address, product name, trademark, net weight, production date, batch number, grade and number of this standard, and in accordance with the provisions of GB190, indicate "flammable, Corrosion" sign
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6.
2 Cyclohexylamine is packed in a clean, dry and strong 200L steel drum, with a net weight of 170kg per drum
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6.
3 Do not approach the fire source during transportation and storage, prevent sun and rain, and handle with care
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6.
4 During operation, protective equipment must be used, and no direct contact with the skin or inhalation into the body is allowed
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