JPH05302915A - Measuring apparatus for molecular weight distribution - Google Patents

Abstract

PURPOSE:To measure molecular weight distribution on line. CONSTITUTION:A solvent feeding device 20 receives the drained liquid from a diluting valve 10 of a sample introducing part, whose temperature is maintained, and the drained liquid from an injector 22 of HPLC, regenerates solvent and feeds the solvent as diluting liquid to the diluting valve 10 and as a moving phase to the injector 22. The solvent feeding device 20 is an explosion-proof type and is the continuous feeder. An explosion-proof type deaerator 42 is provided between a pump 18, which feeds the solvents of the solvent feeding device 20 and a solvent tank 40 into the diluting valve 10, and a pump 28, which feeds the solvent into the injector 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device for measuring the distribution of molecular weight or degree of polymerization by using size exclusion chromatography (also called gel permeation chromatography GPC), and in particular, it is connected to a process line of the chemical industry and has a process side. The present invention relates to a molecular weight distribution measuring apparatus for a process capable of collecting and analyzing a sample on-line from.

[0002]

Size exclusion chromatography is used to measure the molecular weight of high molecular compound samples. In size exclusion chromatography, a solvent is injected into a column packed with a porous packing material under conditions that do not interact with the stationary phase.
The samples are separated by molecular weight. In a laboratory or a laboratory, a sample is diluted with a solvent and injected into a size exclusion chromatography device for measurement.

[0003]

However, when trying to measure the molecular weight distribution on the process line, a size exclusion chromatography device for laboratories is directly installed at the process site, and samples are taken online from the process side for measurement. You cannot do it. Therefore, an object of the present invention is to make it possible to measure the molecular weight distribution online by using a size exclusion chromatography device.

[0004]

The present invention provides a molecular weight distribution measuring device for a process, a size exclusion chromatography device as an analysis part, and a sample which is sampled from the process side and diluted and introduced into the analysis part. A sample introduction part,
A circulation channel for the solvent can be formed between the sample introduction part and the analysis part, and the solvent is supplied as a diluent to the sample introduction part and the mobile phase to the analysis part. An apparatus and an explosion-proof deaeration device provided between the continuous solvent supply device and the sample introduction part and the analysis part.

[0005]

When the sample is cooled from the process side until it is diluted, the sample may solidify. Therefore, the sample introduction part is kept at a temperature at which the sample does not solidify. The diluting liquid and the solvent supply device used as the mobile phase are explosion-proof so that they can be safely installed at the process site, and the solvent can be circulated continuously to reduce the cost of the solvent. If the diluent or mobile phase contains air bubbles, the air bubbles will remain in the pump head, etc. and a stable flow rate will not be obtained.Therefore, a deaerator is provided, but the deaerator is also explosion-proof for safety. ing.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an embodiment. A circulation flow path including a pump 4 and a cross flow type ceramic filter 6 is connected to the polymerization reactor 2 in the process line. A diluting valve 10, which is a six-way valve, is connected to the filtrate outlet of the filter 6 via a sample pump 8. The dilution valve 10 is the measuring loop 1
2, and a dilution valve 10 having a mixer 1 for diluting a sample.
4 is connected, a diluent pump 18 for supplying a diluent is connected, and a discharge flow path to the solvent supply device 20 is also connected. A portion including the filtering device and the diluting device is a sample introducing portion, and the sample introducing portion is kept at an appropriate temperature according to the sample in order to prevent the sample from solidifying before being diluted. The heat retention temperature is, for example, 150 ° C to 200 ° C.

The outlet of the mixer 14 is connected to a size exclusion chromatography high performance liquid chromatograph (HPLC) injector 22. The injector 22 is of a six-way switching valve type and has a metering loop 24. The sample supplied from the mixer 14 to the injector 22 and not injected into the column 26 is discharged to the solvent supply device 20. The injector 22 is further connected to a mobile phase pump 28 that supplies a mobile phase to the HPLC, and a column 26. Reference numeral 30 is a detector, and 32 is a data processing device.

The liquid discharged from the dilution valve 10 and the injector 2
Dilution valve 10 that receives the effluent from 2 and regenerates the solvent
The solvent supply device 20 supplied as a diluent to the injector 22 and as a mobile phase to the injector 22 is an explosion-proof continuous supply device. The solvent supply device 20 includes an evaporator 34 having a heating means 36 for vaporizing the solvent from the liquid discharged from the dilution valve 10 and the injector 22, and a condenser 38 for cooling and liquefying the solvent vapor from the evaporator 34 to regenerate the solvent. , And a solvent tank 40 for storing the solvent that has been regenerated by being cooled by the condenser 38. A pump 18 for supplying the solvent in the solvent tank 40 to the dilution valve 10.
A deaerator 42 is provided between the pump 28 and the solvent tank 40 that supply the injector 22, and the deaerator 42 is also explosion-proof. An example of the deaerator 42 is
Pass the solvent through the tube made of porous synthetic resin film,
The outside of the tube is depressurized to reduce the molecular weight of oxygen,
It can degas nitrogen and carbon dioxide.

Next, the operation of this embodiment will be described.
Solvents used as diluents and mobile phases include trihydrofuran, benzene, toluene, chloroform, o
-Dichlorobenzene, 1,2,4-trichlorobenzene, o-cresol, N, N-dimethylformamide,
Hexafluoroisopropanol etc. is selected and used according to the sample and filler.

Prior to online use, a standard sample having a known molecular weight is previously introduced from the sample introduction part, and a constitution curve is prepared from the elution time thereof. When the sample is introduced from the process line, the sample introduction part is kept at an appropriate temperature to prevent the sample from solidifying, the dilution valve 10 is used as a flow path of the solid line to flow the sample into the measuring loop 12, and then the dilution valve 10 is used. Is switched to the flow path indicated by the broken line, and the sample in the measuring loop 12 is sent to the mixer 14 together with the solvent. At this time, the injector 22 is set as a solid flow path so that the sample from the mixer 14 flows from the measuring loop 24 to the solvent supply device 20. When the time for the sample to pass through the metering loop 24 is observed, the injector 22 is switched to the flow path indicated by the broken line, and the solvent from the pump 28 sends the sample to the column 26.

[0011]

According to the present invention, since the sample introduction portion is kept warm and the solvent supply device and the degassing device are explosion proof, the molecular weight distribution can be measured online at the process site. Also, since the solvent is circulated so that it can be continuously supplied, the amount of solvent used is reduced and the running cost is reduced.
The frequency of solvent supply can be reduced and labor can be saved.

[Brief description of drawings]

FIG. 1 is a flow chart showing an example.

[Explanation of symbols]

 2 Polymerization reactor 6 Ceramic filter 10 Dilution valve 14 Mixer 20 Explosion-proof continuous solvent feeder 22 Injector 26 Packed column 30 Detector 34 Evaporator 38 Condenser 40 Solvent tank 42 Explosion-proof degasser

Claims (1)

[Claims] 1. A size exclusion chromatography apparatus as an analysis unit, a heat-insulated sample introduction unit for collecting a sample from the process side, diluting it, and introducing it into the analysis unit, and between the sample introduction unit and the analysis unit. It is possible to form a circulation channel of the solvent with, the explosion-proof solvent continuous supply device for supplying the solvent as a mobile phase to the diluent and the analysis part to the sample introduction part, the solvent continuous supply device and the sample introduction part and An apparatus for molecular weight distribution measurement for a process, comprising an explosion-proof deaeration device provided between the analysis unit and the analysis unit.