SU1057782A1 - Device for introducing sample into gas chromatograph - Google Patents

Abstract

A GAS CHROMATOGRAPH DEVICE FOR ADMITTING A SAMPLE containing a metallic bpok with an electric heating system inside which an evaporation chamber is made. A cannap for supplying a gaa-carrier to an evaporation chamber, a canap for inserting a syringe needle into the evaporation chamber, inserting a vacuum into the evaporation chamber; and having a central answer to the passage of the needle, the ao membrane of the self-ironing material, pressed against the guide sleeve - through the rotary captive nut nut, with a chopper to connect the chromatograph to the olts and a tee with a seal that connects the evaporation chamber with a coypus, different from that, in order to provide the ability to work with filled and capillary copos, as well as to ensure that the sample is introduced directly into the capillary heme, it is equipped with a washer in contact with the membrane on the side opposite to the location of the guide bush, which has a cylindrical protrusion entering the hole of the heating nut-radiator, a central hole located at the back of the hole in the guide bush, and an eccentric There is a located hole, the surface of the plate facing the membrane has a tapered shape, and the sleeve with the side facing the membrane has a central P1 tapered groove.s 00 to

Description

The invention relates to devices for injecting a sample of a substance under test using a syringe into a chromatographic box and can be used in gas-liquid chromatography, chromatography, mass spectrometry, IR spectrometry for entering the minimum possible sample amounts when working with stuffed metal, as well as with metal and glass samples. either with or without the use of a gas flow divider, it can also be used when working with direct introduction of a sample into the capillary columns. An instrument for injecting a sample using a syringe into a chromatographic column designed to work with capillary columns without a gas flow divider and containing a metal block with electrical heating, inside which is made an evaporation chamber, a chamber for supplying carrier gas to the evaporation chamber, a needle entry channel the syringe into the vapor chamber, hermetically sealing the membrane with a self-sealing material, a cap nut for the ator and a nozzle for connecting the chromatographic column. However, this device will not allow work to be done with the direct introduction of the sample inside the column. The closest to the proposed invention is a device for introducing a sample into a gas chromatograph containing a metal block with electrical heating, inside which an evaporation chamber is made, a carrier gas supply channel, an evaporation chamber, a syringe needle entry channel into the evaporation chamber, a guide sleeve installed in the channel dp of the needle insertion of the needle and having a central hole for the passage of the needle, a membrane made of self-sealing material, pressed to the guide sleeve by means of a cap nut radiator, an outlet nipple for Connect the chromatographic column and a tee with seals connecting the evaporation chamber to the column 2. The known device cannot be used to work with metal and glass capillary columns without a gas flow divider. Due to the presence of large dead volumes (a large volume of lawn of the right tube insert, the use of a connecting tube to connect the column and flow divider to the evaporation chamber), working without a gas flow divider results in blurring of chromatographic peaks in the chromatogram. The known device cannot also be used for direct insertion of the plugs into the capillary columns due to the large distance between the location of the column (tee) and the syringe syringe, as well as due to the large size of the internal diameter of the sleeve and the gas guide tube insert. The purpose of the invention is to provide the possibility of working with filled and capillary colons, as well as ensuring that the sample is introduced without dividing the flow and directly into the capillary column. This goal is achieved by having a device for introducing a sample into a gas chromatograph containing a metal block with electrical heating inside which a chamber is made, evaporation, a channel for supplying carrier gas to the evaporation chamber, a channel for introducing the needle of the syringe into the evaporation chamber, guiding inset in the needle insertion channel of the syringe and having a central hole for the passage of the needle, a membrane made of self-sealing material, pressed against the guide sleeve by means of a cap nut radiator, an outlet fitting for The connections of the chromatographic column and the tee with seals connecting the chamber to the column are equipped with a washer in contact with the membrane on the side opposite to the location of the guide sleeve, which has a cylindrical protrusion entering the opening of the radiator nut, A mechanical hole located coaxially with a hole in the guide sleeve and an eccentrically located hole, the washer surface facing the membrane has a tapered shape, and the sleeve from the side facing the membrane has a central conical recess. FIG. 1 shows the proposed device, in the position of introducing the sample inside the capillary column, section; in fig. 2 chromatogram of free fatty acids (molecular weight 172-340) of fatty man secretions; in fig. 3 is a chromatogram of an individual mixture of C. jir-Old n-hydrocarbons with a molecular weight of 212-338. The device is made in the form of a metal 1, equipped with a 2 dp tube of sample injection of the substance under investigation, an evaporation chamber 3, a nasal gas channel 4, an outlet, an outlet fitting 5 of the block 1p of the konkon 6 and the heat sensor 7. There is a spanning element, and a spanning spanner has a spanning spanner and a spanning spanner of the device. 8, the inner diameter of which corresponds to the outer diameter of the digger 6. The gas guide tube 8 is fixed in the evaporation chamber 3 by means of a tee 9 with a seal 10 connected with an end made in the form nuts, to the outlet fitting 5 1. Inside the tube unit 2 for inputting .polozhena races sample sleeve 11 with a through otverotiem diameter 12 O, O4 mm. The aperture 12 has, on one side, a conical bore for the centering-insertion of the needle 13 of the syringe 14, and on the other, a cylindrical bore for fitting vutuka 11 onto the column 6. On top of the sleeve 11 there is a membrane 15 of heat resistant rubber, on which a metal washer 16 is fitted, the exact direction of the needle of the syringe. The washer 16 is made on one side with a cylindrical protrusion that fits into the central hole 17 of the cap nut of the radiator 18, presses the diaphragm 15 against the sleeve 11, and on the other side with the surface treated with a cone. The washer 16 has a central opening 19 for introducing a needle of the syringe and an eccentric located opening 2O for evacuating gases from the cavity 21 of the sleeve 11. The sample introduction pipe 2 is equipped with a cooled tube 22. The chromatography column 6 is connected to the evaporation chamber 3 by means of a tee 9 and fixed in it A nut 23 with a seal 24 is used. A side outlet 25 of the tee 9 is closed with a nut 26 and a seal 27. The syringe 14 is provided with a microdot 28 retracted inside the needle 13. The capillary column 6 is provided at the inlet with two holes 29 (in the case of with direct injection of the sample into the column). When working with a flow divider, a tee 9 is connected to a trap 30 to trap the discharged analytes, which is connected to the needle valve 31. The device works as follows. Yrie working with capillary heads without a gas flow divider; The following material, applied to the microstub 28, retracted inside the needle 13 of the syringe 14, is inserted through the hole 19 of the washer 16, the membrane 15 and the hole 12 of the sleeve 11 into the internal space of the gas guide tube. breathing 8 by extending the microstubes 28 from the needle 13.. Due to the fact that the protrusion of the cylindrical shape 16 enters the hole 17 of the cap nut radiator 18, and the sleeve 11 is made with a through hole 12 with a diameter of 0.04 mm in a chestoid bore, the needle 13 of the syringe 14 and, consequently, the microcore 28 with the breakdown enters exactly into the middle of the gas guide tube 8. The introduced sample evaporates in the internal volume of the liner 8. The vapors are picked up by the carrier gas flow coming to channel 4 and are directed to the chromatographic column 6. The small internal volume of the vacuum tube 8 ( 10 µl) in which Sample JBBOdits on microstub 28 diameter. 0, OO5 mm, allows work to be carried out without the use of a gas net divider. In addition, the implementation of a small-volume tube 8 and crepe & tee 9, in which column 6 is fixed, is not directly connected to the outlet fitting 5 of unit 1, significantly reducing the dead volumes of the device, which allows improving the accuracy of quantitative and qualitative chromatographic analysis. I The tightness of the device is achieved with the help of the membrane 15, on which the clamp 16 is seated. Due to the fact that the surface of the washer 16, which is in contact with the membrane 15, is tapered, the membrane 15 expands when heated and does not press into the conical cavity of the insert 11. When In the case of temperature programming, gases washing the membrane 16 in the conical cavity 21 in the sump 11, which can fall into column 6 and negatively affect the results of the analysis, are removed using a conventional medical needle that is inserted into the hole 2.O and walks through the membrane 15 into the cavity of the sleeve 11. When working with direct injection of the sample into the inside of the column with an internal diameter of 0.05-1.5 mm, the end of column 6 enters the cylindrical bore of the 11 helical boring corresponds to the outer: 1 sleep the diameter of the button. In this case, the evaporation KaiMepoft will coil the inlet of column 6, and the carrier gas enters column 6 through two holes 29 (the second hole is not shown) at its inlet. In this case, in the case of columns with an internal diameter of 0.05-0, the 4 mm needle 13 of the microsyringe 14, after perforation of the membrane 15, is retained in front of the opening 12. sleeve 11, and microdrill 28 with the applied sample is pulled out of the needle and enters through the opening 12 into the inside of the capillary circuit 6. In the case of the use of capillary KoftoHOK with an inner diameter of 0.5-1.5 mm, the 13a itself enters the column, and then micro1: Rod 28 is extended. When working with stuffed columns, the liner 8 is not used, the sample is introduced directly into the column fixed in the evaporation chamber 3. When working with concentrating devices, a cooling agent is supplied to the tube 22. When working with the gas flow divider, the lateral outlet 25 of the tee 9 is connected through the trap 30 to the needle valve 31, the necessary dp limiting the flow rate of the gas carrier on discharge. To quantify the reproducibility of the results of the device operation with the direct introduction of the sample into the 82 82 capillary column with an inner diameter of 0.25 and O, 3 mm, it was transplanted with tenfold and threefold repetition of two mixtures of organic substances {different in molecular weight: free higher fatty acids of fatty secretions of a man (male - 41 years old), having a molecular weight of 172-340; an individual mixture of n-hydrocarbons C) 4 with a molecular weight of 212-338. The resulting chromatograms are shown in FIG. 2 and 3. The statistical processing of the data obtained is given, the error varies with for higher fatty acids in the range of 0.2-7.1 rel.% And for Cjc-C.24 hydrocarbons 0.6-4.5 rel.% Depending on the concentration of the individual composition of the components and the substance available to the researcher. Thus, the device is universal, and can be used but when working with any chromatographic columns (packed, metal and glass columns, metal-based and glass capillary columns) using both deciators of gas flow and € 1. In addition, the device can be used to work with directly introducing the sample into the capillary columns.

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Claims (1)

A device for introducing a sample into a gas chromatograph containing a metal block with electric heating, inside which an evaporation chamber is made, a channel for supplying carrier gas to the evaporation chamber, a channel for injecting the syringe needle into the evaporation chamber, a guide sleeve installed in the canopy for inserting the syringe needle and having a central hole for the passage of the needle, a membrane of self-sealing material, pressed to. guide sleeve - with a union nut-radiator, an outlet fitting for connecting a chromatographic column and a tee with seals connecting the evaporation chamber to the column, differing in those that, in order to ensure the possibility of working with filled and capillary columns, as well as ensuring the input of the sample directly into the capillary column, it is equipped with a washer in contact with the membrane from the side opposite to the location of the guide sleeve ®, which has a cylindrical protrusion entering the hole of a radiator cap nut, a central hole located coaxially with the hole in the guide sleeve and an eccentric hole, the surface of the washer facing the membrane has a conical shape, and the sleeve from the side facing the membrane has a central conical recess. ^! 1 1057782