Determination of Oxygen in Gas Phase on Industrial Butadiene Liquid (1)

1 Scope

1.

1.

2 Normative references

The clauses in the following documents have become clauses of this standard after being quoted in this standard

GB/T3723 General rules for the safety of sampling of industrial chemical products (GB/T3723-1999, idt ISO 3165:1976

GB/T6681 General Rules for Sampling of Gas Chemical Products

GB/T8170 Numerical Rounding Rules

3 Gas chromatography

3.

The gas sample is injected into the chromatograph through the sampling device and carried by the carrier gas into the pre-separation column.

3.

3.

Argon gas: The purity is not less than 99.

3.

Nitrogen or argon: the purity is not less than 99.

Oxygen: The purity is not less than 99.

3.

3.

Activated carbon (for chromatography): particle size 0.

5A molecular sieve (for chromatography): particle size 0.

3.

3.
3.
1 Gas chromatograph: a gas chromatograph with a quantitative gas sampling device, a backflushing device and a thermal conductivity detector.
The peak height of the instrument under the operating conditions given in this standard should be at least two times greater than the noise of the instrument.
Times,

3.
3.
2 Loop: 1mL or 5mL
.

3.
3.
3 Pre-separation column

Stationary phase: activated carbon (3.
2.
4);

Column tube: stainless steel, length 1m, inner diameter 4mm
.

3.
3.
4 Separation column

Fixed: 5A molecular sieve (3.
2.
4);

Column tube: stainless steel, length 2m, inner diameter 4mm;

Activation of 5A molecular sieve: Wash the 5A molecular sieve with distilled water to remove dust, put it in an oven and heat it to 120°C, keep it at a constant temperature for 4 hours, and install it in a column
.
Under argon flow (approximately 100mL/min), the separation column is heated to 310℃～320℃, and kept constant for 1h～4h to remove water, carbon dioxide and trace organic matter
.
The activation time depends on the moisture absorption of the molecular sieve
.

3.
3.
5 Recording device: electronic integrator or chromatography workstation
.

3.
3.
6 Gas injection valve.

3.
3.
7 Backflushing device: six-way valve
.

3.
4 Sampling

According to the method specified in GB/T3723 and GB/T6681, the butadiene liquid upper gas phase sample is taken
.

Related links: Determination of tert-butylcatechol (TBC) in butadiene for industrial use (4)