SU1314258A1 - Device for introducing samples in liquid chromatograph - Google Patents

Abstract

This invention relates to the field of liquid chromatography, specifically to devices for introducing a mixture of liquid substances into a liquid chromium / tograph column. It can be used in the analysis of mixtures of liquid substances in such areas of science and technology. as medicine, biologists, pharmaceutical and food industries, in agriculture, etc. The aim of the invention is to increase the reliability of the device. The device for introducing samples into the liquid chromatograph column is equipped with an apparatus for creating pressure in the chamber for introducing samples, which is sealed in the form of a bellows. forming a channel for introducing the sample carrier. The device is equipped with a tool for compressing the bellows in the direction of the sample introduction chamber, made in the form of a lever. 1 hp f-ly, 2 ill. I (L

Description

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The invention relates to liquid chromatography and can be used in the analysis of mixtures of liquid substances in various fields of science and technology, in particular in medicine, biology, the food industry, etc.

The object of the invention is to increase the reliability of the device.

In Fig. 1 shows the proposed device, the section; FIG. 2 shows an example of a sample introduction chamber.

The device contains a chamber I for sample introduction, connected through a transition channel 2 and hydroresistance

3 with an inlet of the chromatographic column 4. The hydraulic resistance 3 is a needle valve including a metal needle 5 connected to a micrometric screw 6. In the hydraulic resistance case 3, an upper sealing ring 7 is installed, for example Teflon, and at the entrance to the chromatographic column

4 - the lower sealing ring 8, into which the tapered end of the needle 5 enters. Under the sealing ring 8 there is a metal disc 9

with a central conical flow guide 10, the lower end of which is located above the partition 11 of a porous material, for example, cermet, serving as a distributor for the flow of flux fed to chromatographic column 4 through channel 12. A bellows 13 is installed above the sample introduction chamber 1, the internal volume of which is communicates with chamber 1. The upper end wall of the bellows 13 is made in the form of a disk 14 with a central hole 15 forming a channel for inserting sample carrier 16 (Fig. 2). The device is equipped with a device for compressing the bellows 13 in the direction towards the camera 1 for introducing samples, which is made in the form of a lever 17 mounted above the bellows 13 and connected at one end to the ball support 18. On the lever 17 a sealing element 19 is placed above the central hole 15 of the disk 14 and is designed to seal the hole 15 when moving the loading arm of the lever 17 down. In the disk 14 of the bellows 13 is made of the horizontal channel 20 connected to the drain tube 21,

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under which is installed a collection of 22 eluent.

Chamber 1 for sample introduction can be performed (FIG. 2) in the form of two

parallel connected channels 23 and 24, one of which (channel 23) has a smaller diameter and is located coaxially with channel 25 for insertion of sample carrier 16. As a sample carrier 16, a microsyringe can be used, the needle 26 of which is inserted through the opening 15, the internal volume of the bellows 13 and the channel 15 in. channel 23 of camera 1 for sample introduction. The output of the column 4 is installed detector 27.

The device works as follows.

Before the start of operation of the liquid chromatograph, a flow of flux is fed through the channel 12 to the inlet of column 4 from the eluent flow rate driver (not shown). The main part of the flow of eluent passes through column 4 and the detector 17 and enters the main collection of eluent (not shown). A smaller part of the flow through the hydroresistance 3 through channel 2 enters the chamber 1 for sample introduction. Fills the bellows 13 and through the channel 20 and the drain pipe 21 enters the collection 22 of eluent. Using a micrometer screw 6, smoothly changing the position of the needle 5 in the sealing

ring 8, set the flow rate of a smaller eluent flow such that the internal volume of chamber 1 is filled within a period of time equal to 5-15 seconds, i.e. to perform

condition V,

w7 -

(one)

45

where V is the internal volume of the chamber 1; W - volumetric flow rate

eluent passing through it.

After installing the required consumption of the eluent through the column 4 and chamber 1 for sample introduction, the sample is introduced. To do this, taking the metered amount of the sample using a microsyringe 16 and pushing the lever 17 away from the orifice 15 of the bellows I 3, inserts the needle 26 into the channel 23 of the chamber 1 and smoothly inject the sample into the chamber 1. Then the needle 26 is removed from the chamber 1, Move the lever 1 7 to the bellows 13 so as to install the packing device 3

against the opening 15. Next, seal the opening I5 with the sealing element 19 and sharply compress the bellows 13 by the amount of its maximum stroke (7 mm). In this case, the eluent in the volume of the bellows 13 displaces the entire volume of liquid together with The breakdown of the analyzed substances from the chamber at the entrance to the chromatographic column 4 through hydroresistance 3 The implementation of chamber 1 in the form of parallel-connected channels 23 and 24, the inner diameter of one of which is approximately equal to the outer diameter of the needle 26 of the microsyringe, ensure When the sample is injected into the end of channel 23 (Fig. 2), the sample of analytes (blackened part of the internal volumes of channels 23 and 24 in Fig. 2) comes under the action of the forcing effect of the microsyringe and the flow of eluent entering the chamber 1 through hydroresistance 3, into a wider channel 24. The volume of this channel is selected from the condition (1). Under this condition, in the time required for removing the microsyringe needle 26 from the channel 23 and the bellows 13 and sealing the bellows 13 with a sealing element 19 (3-6 s), the sample of the analyzed substances does not have time to leave the volume of the chamber 1 into the volume of the bellows 13. Thus, during compression of the bellows 13, guaranteed flushing of the volume of chamber 1 and quantitative input of a sample of analytes is carried out.

The proposed device in comparison with the known has more pros142584

thuyu and reliable design. It lacks a sealing membrane made of materials that interact with the solvents used in chromatography, which are used as eluents.

Claims (2)

Invention Formula fO 1. A device for introducing samples into a liquid chromatograph, containing a chamber for introducing samples, connected to the inlet of the chromatographic column through a choke, a channel for introducing a sample holder and an instrument for creating pressure in the chamber for introducing samples, device reliability, fixture 0 to create pressure in the sample inlet chamber, performed in the form of a bellows mounted above the sample inlet chamber, the upper end wall of which is designed as 5 discs with a central hole, coaxial with the channel for introducing the sample carrier, the device being equipped with a device for compressing the bellows in the direction towards the chamber for introducing 30 samples and means for sealing the channel for introducing the sample carrier. 2. The device pop. 1, which differs from the fact that the camera is for 35 sample entry is complete in two parallel-connected channels of different diameters, one of which, having a smaller diameter, is coaxial with the channel for  About input sample carrier. fie. one