Dodecanol (3)

4.

4.

Alcohol reacts with excess acetylation reagent.

4.

4.

4.

4.

Preparation of aldehyde-free ethanol: 5g aluminum flakes were refluxed in 1000mL neutral anhydrous ethanol for 1h, and then distilled immediately

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4.

Weigh 0.

4.

The hydroxyl value X3 (mg KOH/g) is calculated according to formula (3):

In the formula: V ₀ -the volume of the potassium hydroxide ethanol standard titration solution consumed in the blank test, mL;

V ₃ —The volume of potassium hydroxide ethanol standard titration solution consumed by the titration sample, mL;

c ₃ —The concentration of potassium hydroxide ethanol standard titration solution, mol/L;

0.

m—the mass of the sample, g

Take the arithmetic average of two parallel determinations as the result

4.
5.
5 Tolerance

The difference between the two parallel determinations shall not be greater than 3mg KOH/g
.

4.
6 Determination of purity

4.
6.
1 Reagents and materials

4.
6.
1.
1 Carrier gas and auxiliary gas

a.
Carrier gas: nitrogen or helium , with a purity greater than 99.
9%;

b.
Fuel gas: hydrogen, with a purity greater than 99.
7%;

c.
Combustion gas: secondary air purification
.

4.
6.
1.
2 Reagents and materials used when preparing the color harmonic column

a.
Fixative: SE-30+polyethylene glycol-20M;

b.
Carrier: 101 white silanized carrier
.
Granularity 0.
18～0.
25mm (80～60 mesh);

c.
Solvent: chloroform
.

4.
6.
2 Apparatus

4.
6.
2.
1 Gas chromatograph

Detector: hydrogen flame ionization detector
.

4.
6.
2.
2 Column

a.
Column tube: stainless steel tube or glass tube with an inner diameter of 3.
5～4.
0mm and a length of 2m
.

b.
Filling:

Proportioning: Carrier: Fixing solution=100:5 (of which polyethylene glycol-20M is 0.
05%) (mass ratio) Method of applying fixative solution: Weigh 1.
25g methyl silicone SE-30 and 12.
5mg polyethylene Diol-20M is added to a beaker, 100mL of chloroform is added to dissolve, 25g of the loading body, after a little stirring, it is dried under an infrared lamp or naturally dried
.

c.
Filling method: Cover the outlet end of the chromatographic column (the end connected to the detector) with a little glass wool, draw a vacuum from the outlet end, and load about 20g of stationary phase under gentle vibration, fill it evenly and tightly, and use it again The glass wool is plugged
.

d.
Aging of the chromatographic column: Put the filled chromatographic column into the column box of the chromatograph, after checking the air tightness, pass nitrogen, gradually increase the temperature to 210°C, and age at 210°C for more than 8 hours until the baseline is stable
.

4.
6.
2.
3 Sampler: Micro glass syringe
.

4.
6.
2.
4 Chromatographic data processor: recorder or integrator
.