Industrial butadiene purity and determination of hydrocarbon impurities. Gas chromatography (2)

5 Instruments

5.

A gas chromatograph equipped with a flame ionization detector (FID).

5.

The chromatographic column and typical operating conditions of Zhuanjian are shown in Table 1.

Table 1 Recommended chromatographic columns and typical operating conditions

Figure 1 Typical chromatogram

5.

5.

Who can meet the following requirements a liquid injection valve can be used: when it is not lower than the temperature of the butadiene vapor pressure, capable of butadiene in the liquid state repeatedly injected and chromatographed to meet the requirements

The flow diagram of the liquid sampling device is shown in Figure 2

Figure 2 Schematic diagram of the flow of the liquid sampling device

5.

5.

Connect the evacuated sample cylinder to dry E, first open valve A, then open valve B, so that the liquid sample is completely vaporized in the sample cylinder.

Note: The sampling cylinder containing the liquid sample should be placed in the laboratory for sufficient time to allow the temperature of the liquid sample to balance with the room temperature before performing the above operations, and when a small amount of liquid sample is obtained in the pipeline cylinder, the gasification should be completed as soon as possible Operation, avoid the tube filled with liquid sample passing over the cylinder, which increases the possibility of bursting with the residence time

5.

5.

Integrator or chromatography workstation

6 sampling

Take samples according to the safety and technical requirements specified in GB/T3723 and GB/T13290
.

Figure 3 Schematic diagram of the vaporization device for a small amount of liquid sample

Figure 4 Schematic diagram of a water bath vaporization device for liquid samples