JP6419231B2 - Sampling unit - Google Patents

Description

  The present invention relates to a sampling unit that adsorbs a trace component in a gas / liquid, thermally desorbs the trace component by heating, and collects a sample used in an analysis method such as gas chromatography-mass spectrometry.

  Conventionally, as a sampling unit for directly collecting a liquid sample or a fine solid sample used in a thermal analysis method such as evolved gas analysis, pyrolysis gas chromatograph-mass spectrometry, a sampling unit in which a metal microcoil is welded to a sampling rod is used. It has been proposed (see Non-Patent Document 1).

Kaneko et al., "Trial production of GC sampling device using microcoil and its application", BUNSEKI KAGAKU, Vol.4, No.5, pp.365-369 (2015)

  In the sampling unit described in Non-Patent Document 1, it is conceivable that the surface of the metal microcoil is deactivated and covered with a resin. When doing so, if the resin that covers the surface of the deactivated metal microcoil has a different polarity, the sample adsorbed on the resin also differs. It is considered that various components in the sample can be selectively analyzed by sampling.

  However, in the conventional sampling unit, since the metal microcoil is welded to the sampling rod, in order to use different resins with different polarities depending on the object to be analyzed, sampling is performed for each resin polarity. The disadvantage is that different sampling units must be prepared.

  It is an object of the present invention to provide a sampling unit that can eliminate such inconvenience and can easily use and sample resins having different polarities depending on the analysis target.

In order to achieve this object, the sampling unit of the present invention is a sampling unit that collects a sample to be introduced into a heating unit of a gas phase component analyzer and vaporizes the sample by being heated in the heating unit. A sample collection rod and a sample collection piece, the sample collection piece covering a surface and inactivating an undercoat layer, and a resin coating layer covering the surface of the undercoat layer and adsorbing the sample A plurality of types of sample collection pieces having different polarities of the resin forming the resin coating layer, the sample collection pieces are detachably attached to the tip of the sample collection rod, and the sample collection pieces are Each polarity of the resin forming the resin coating layer is characterized by being identifiable by an inorganic pigment capable of maintaining the molecular structure when heated by the heating unit .

  The sampling unit of the present invention includes a sampling rod and a sampling piece, and the sampling piece covers an undercoat layer that covers and inactivates the surface, covers the surface of the undercoat layer, and adsorbs the sample. A resin coating layer. The resin coating layer can selectively analyze various components in the sample by properly using resins having different polarities depending on the analysis target.

At this time, according to the sampling unit of the present invention, a plurality of types of sample collection pieces having different polarities of the resin forming the resin coating layer are provided, and each sample collection piece is detachably attached to the tip of the sample collection rod. Therefore, each sample-collecting piece can be exchanged as necessary, and resins having different polarities depending on the analysis target can be easily used and sampled.
By the way, in the sampling unit of the present invention, when the resin forming the resin coating layer is a resin having a different polarity depending on the analysis target, and when a plurality of types of the sample collection pieces are provided depending on the polarity of the resin, the sample There is a problem in that the difference in polarity of the resin cannot be discriminated from the appearance of the collected piece.
Therefore, in the sampling unit of the present invention, the coiled sample collection piece can be identified by an inorganic pigment capable of maintaining the molecular structure when heated by the heating unit for each polarity of the resin forming the resin coating layer. Is colored.
As a result, the sample collection piece can easily discriminate the polarity of the resin forming the resin coating layer from the appearance, and the sample collection piece including the resin coating layer appropriate for the analysis target can be used without error. It can be used reliably. In addition, since the inorganic pigment used for coloring the resin coating layer can maintain the molecular structure when heated by the heating unit, it can be avoided that the inorganic pigment becomes an obstacle to analysis.

  In the sampling unit of the present invention, it is preferable that the sample collection piece is a metal coil, the sample collection rod has a sharp tip, and the metal coil is detachably attached to the tip of the sample collection rod. . According to the configuration in which the sample collection piece is a metal coil and the sample collection rod has a sharp tip, the tip of the sample collection rod is pushed inside the metal coil, and the metal coil is inserted into the sample collection rod. It can be easily attached and detached by fitting it to the tip.

  In the sampling unit of the present invention, examples of the inorganic pigment used for coloring the resin coating layer include ceramic pigments, composite oxide pigments, bengara, basic lead chromate, titanium white, zinc white, and carbon. One or more pigments selected from the group consisting of: The ceramic pigments include Co-Cr-Fe pigments, Co-Mn-Fe pigments, antimony tin gray, zircon gray, Zn-Cr-Fe pigments, Zn-Al-Cr-Fe pigments, Naples. Yellow, praseodymium yellow, vanadium tin yellow, vanadium zirconium yellow, Zr-Ti-V-In pigment, chromium titanium yellow, Zr-Si-Cd-S pigment, Zr-Y-V pigment, peacock, Victoria Green, Chrome green, Cr pigment, Co-Cr pigment, bitumen, sea bream, Co-Zn-Si pigment, Co-Si pigment, vanadium zirconium blue, chrome tin lilac, lilac, chrome tin pink, ceramic red, salmon One or more pigments selected from the group consisting of pink, chrome alumina pink, and fire red can be used.

The typical sectional view showing the example of 1 composition of the gas phase ingredient analyzer. The typical sectional view showing the example of 1 composition of the sampling unit of the present invention. The typical sectional view showing other examples of composition of the sampling unit of the present invention. The side view which expands and shows the principal part of the sampling unit of this invention. FIG. 5A is a chromatogram showing an analysis example of a sample collected using the sampling unit of the present invention, FIG. 5A is a chromatogram when a nonpolar resin is used as a resin for forming the resin coating layer, and FIG. 5B is a resin coating layer. FIG. 5C is a chromatogram obtained when a second resin having a medium polarity is used as a resin for forming a resin coating layer. Fig. 5D is a chromatogram when a resin having a large polarity is used as the resin for forming the resin coating layer.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

  As shown in FIG. 1, a gas phase component analyzer 1 used for an analysis method such as gas chromatograph-mass spectrometry includes a thermostat 10, a heating unit 11 provided above the thermostat 10, and an opening of the heating unit 11. From a septum 12 that closes the end, a carrier gas introduction pipe 13 connected to the heating unit 11 outside the thermostat 10, a separation column 14 such as a capillary column arranged inside the thermostat 10, and a mass spectrometer And a detecting unit 15. The separation column 14 is connected to the lower end of the heating unit 11 at one end and is connected to the detection unit 15 at the other end. Moreover, the heater 16 is arrange | positioned inside the heating part 11, and the split vent pipe 17 is connected to the lower part.

  According to the gas phase component analyzer 1, a sample introduced by the sampling unit 2 punctured in the septum 12 is heated by the heater 16 in the heating unit 11, thereby generating a gas phase component composed of a mixture of a plurality of compounds. Let The generated gas phase component is introduced into the separation column 14 by the carrier gas introduced from the carrier gas introduction pipe 13.

  At this time, the split vent pipe 17 opens part of the on-off valve 18 to discharge a part of the gas phase component generated in the heating unit 11 and adjust the amount of the gas phase component introduced into the separation column 14. can do. When the amount of the gas phase component is very small, the entire amount of the generated gas phase component may be introduced into the separation column 14 by closing the on-off valve 18 of the split vent pipe 17.

  The thermostatic chamber 10 is heated to a predetermined temperature, and the gas phase component is separated into each compound constituting the gas phase component by the separation column 14 at the predetermined temperature. Then, each separated compound is detected by the detection unit 15.

  For example, as shown in FIG. 2A, the sampling unit 2 of the present embodiment includes a cylindrical cylinder 20, a plunger 21 that is slidable along the inner wall of the cylinder 20, and the tip of the cylinder 20. And a syringe 24 comprising a cylindrical connection part 22 attached to the cylinder 20 and a cylindrical needle 23 connected to the tip of the cylinder 20 via the connection part 22.

  The plunger 21 includes a gasket 25 at the tip, and the base end portion of the sampling rod 26 is fixed to the gasket 25. A rubber seal member 27 is disposed in the connection portion 22, and the sample collection rod 26 is provided through the seal member 27. The sample collection rod 26 is retracted from the needle 23 by being advanced and retracted by the plunger 21, and a coiled sample collection piece 28 is detachably attached to the tip of the sample collection rod 26.

  Further, the cylinder 20 includes a communication hole 29 that communicates the internal space 20 a of the cylinder 20 and the outside between the gasket 25 and the seal member 27, and a retaining portion 30 that is screwed to the base end side of the gasket 25. Is provided. The tip of the retaining portion 30 protrudes into the cylinder 20 and acts as a retainer for the plunger 21 when the gasket 25 abuts. The retaining portion 30 may be configured such that a part of the cylinder 20 is melted and protruded to the inside, or a tip of a screw or the like may be protruded to the inside of the cylinder 20.

  As shown in FIG. 2A, the sampling unit 2 pushes the plunger 21 to advance the sample collection rod 26, thereby moving the tip of the sample collection rod 26 and the coiled sample collection piece 28 attached to the tip. It can be made to protrude from the needle 23. Further, as shown in FIG. 2B, the sampling unit 2 pulls the plunger 21 to retract the sample collection rod 26, whereby the tip of the sample collection rod 26 and the coiled sample collection piece 28 attached to the tip are removed. It can be accommodated in the needle 23.

  In the sampling unit 2, as described above, when the plunger 21 is pushed, the air in the inner space 20a of the cylinder 20 flows out from the communication hole 29, and when the plunger 21 is pulled, the external air communicates. It flows into the internal space 20a from the hole 29. Therefore, in the sampling unit 2, the plunger 21 can be easily operated.

  Moreover, the sampling unit 2 of this embodiment can also be set as the structure which is not provided with the sealing member 27 and the communicating hole 29, as shown to FIG. 3A and 3B.

  As shown in FIG. 4, the sampling rod 26 is configured such that the distal end portion 26 a is gradually reduced in diameter from the proximal end side toward the distal end and has a sharp distal end. The diameter is 0.3 mm, and the diameter at a position 1 mm from the tip of the tip end portion 26 a is 0.13 mm to 0.15 mm. At this time, the coiled sample collection piece 28 is configured to have an inner diameter of 0.1 mm, and the tip end portion 26a of the sample collection rod 26 is pushed into and fitted inside the coiled sample collection piece 28. The tip 26a can be detachably attached.

  The coiled sample collection piece 28 includes a metal coil such as stainless steel, an undercoat layer that covers and deactivates the surface of the metal coil, and a resin coating layer that covers the surface of the undercoat layer. The undercoat layer may be any material as long as it can coat and inactivate the surface of the metal coil, for example, a silicon coating layer, a quartz coating layer, a titanium coating layer. Etc.

  More preferably, the undercoat layer is the silicon coating layer or the quartz coating layer. In the silicon coating layer or the quartz coating layer, silanol groups are formed on the surface by reaction with moisture in the atmosphere, and the silanol groups can form a chemical bond with the resin forming the resin coating layer.

  The resin coating layer is made of a resin capable of adsorbing a sample, and a resin having a different polarity depending on an analysis target can be used. For example, dimethylpolysiloxane or the like can be given as a nonpolar resin, and cyanopropylphenyldimethylpolysiloxane, a mixture of polyethylene glycol and dimethylpolysiloxane, or the like can be given as a resin having moderate polarity. Examples of the resin having a large polarity include polyethylene glycol.

  In addition, the sampling unit 2 of the present embodiment includes a plurality of coiled sample collection pieces 28 each having a different polarity in the resin forming the resin coating layer, and each coiled sample collection piece 28 has a polarity of the resin. Every color is identifiable. The coloring can be performed by mixing an inorganic pigment capable of maintaining the molecular structure when heated by the heating unit 11 with the resin forming the resin layer.

  The inorganic pigment is preferably capable of maintaining a molecular structure when heated at a temperature of 100 to 400 ° C., and examples of such an inorganic pigment include ceramic pigments, composite oxide pigments, bengara, and basic chromic acid. Lead, titanium white, zinc white, carbon and the like can be used. The ceramic pigments include Co-Cr-Fe pigments, Co-Mn-Fe pigments, antimony tin gray, zircon gray, Zn-Cr-Fe pigments, Zn-Al-Cr-Fe pigments, Naples. Yellow, praseodymium yellow, vanadium tin yellow, vanadium zirconium yellow, Zr-Ti-V-In pigment, chromium titanium yellow, Zr-Si-Cd-S pigment, Zr-Y-V pigment, peacock, Victoria Green, Chrome green, Cr pigment, Co-Cr pigment, bitumen, sea bream, Co-Zn-Si pigment, Co-Si pigment, vanadium zirconium blue, chrome tin lilac, lilac, chrome tin pink, ceramic red, salmon Pink, chrome alumina pink, fire red, etc. can be used.

  In the sampling unit 20 of the present embodiment, the distal end portion 26a of the sample collection rod 26 is pushed into and fitted inside the coiled sample collection piece 28 from which the sample has been collected, and then the sample collection rod 26 is retracted to move the distal end portion 26a. The coiled sample collection piece 28 is accommodated in the needle 23. Next, the needle 23 of the sampling unit 2 is punctured into the septum 12 of the gas phase component analyzer 1 as shown in FIG. 1 in a state where the distal end portion 26 a and the coiled sample collection piece 28 are accommodated in the needle 23. After that, the tip portion 26a and the coiled sample collection piece 28 are exposed from the needle 23, and the sample adsorbed on the resin layer is thermally desorbed by heating in the heating unit 11 to generate a gas phase component. The produced gas phase component is introduced into the separation column 14 and gas chromatography is performed.

  Further, when the sample collected in the coiled sample collection piece 28 is a polymer, the coiled sample collection piece 28 is directly introduced into the thermal decomposition apparatus without being attached to the sample collection rod 26, and the polymer is thermally decomposed. Thus, the gas phase component produced can be introduced into the separation column 14 for gas chromatography.

  Next, examples of the present invention will be described.

[Example 1]
In this embodiment, a silicon coating layer is formed on the surface of a stainless steel coil having an inner diameter of 1 mm and a length of 10 mm, and a resin coating layer having a thickness of 2 μm made of dimethylpolysiloxane as a nonpolar resin is formed on the silicon coating layer. A coiled sample collection piece 28 was prepared. The coiled sample collection piece 28 of the present embodiment is colored white by mixing titanium white as an inorganic pigment into the resin layer.

  Next, 10 milliliters of red wine (Chateau Cure-Bon 1998 French) is placed in a 20 milliliter container, sealed, heated to 50 ° C., and the coiled sample prepared in this example in the headspace of the container. The collected piece 28 was held for 60 minutes to adsorb the aroma of the red wine as a sample.

  Next, after the distal end portion 26a of the sampling rod 26 of the sampling unit 20 shown in FIG. 3A is pushed into the inside of the coiled sampling piece 28 and fitted, as shown in FIG. The tip portion 26 a and the coiled sample collection piece 28 were accommodated in the needle 23.

  Next, the needle 23 of the sampling unit 2 is attached to the septum 12 of the gas phase component analyzer 1 as shown in FIG. Punctured.

  Next, as shown in FIG. 3A, the tip portion 26a and the coiled sample collection piece 28 are exposed from the needle 23 and heated in the heating unit 11, thereby thermally desorbing the sample adsorbed on the resin layer, A phase component was generated. Heating for the thermal desorption was performed by increasing the temperature from 40 ° C. to 180 ° C. at a temperature increase rate of 40 ° C. per minute and holding at 180 ° C. for 3 minutes.

  Next, by opening the on-off valve 18 of the split vent pipe 17, the amount of the gas phase component generated by the thermal desorption was adjusted, and 1/5 of the generated amount of the gas phase component was introduced into the separation column 14. . The gas phase component introduced into the separation column 14 is trapped by immersing a portion of 300 mm from the end of the separation column 14 on the heating unit 11 side in liquid nitrogen, and then taken out from the liquid nitrogen, and the temperature in the thermostatic chamber 10 is adjusted. Gas chromatography was carried out by raising the temperature from 40 ° C. to 300 ° C. at a rate of 20 ° C. per minute and holding at 300 ° C. for 10 minutes.

  As the separation column 14, a metal capillary column (manufactured by Frontier Laboratories) having an inner diameter of 0.25 mm, a length of 30 m, and an inner surface having a dimethylpolysiloxane layer having a thickness of 1 μm was used. The result is shown in FIG. 5A.

  From FIG. 5A, the compounds a to i are separated from the sample adsorbed on the coiled sample collection piece 28 by using the sampling unit 2 equipped with the coiled sample collection piece 28 prepared in this example. I understand that. The compounds a to i are respectively a: ethyl hexanoate, b: phenethyl alcohol, c: ethyl octanoate, d: ethyl nonanoate, e: ethyl decanoate, f:

, G: 2-heptadecanone, h: pentadecanal, i: methyl palmitate.

[Example 2]
In this example, a silicon coating layer is formed on the surface of a stainless steel coil having an inner diameter of 1 mm and a length of 10 mm, and a thickness of cyanopropylphenyldimethylpolysiloxane as a resin having medium polarity is formed on the silicon coating layer. By forming a resin coating layer having a thickness of 2 μm, a coiled sample collection piece 28 was prepared. The coiled sample collection piece 28 of the present embodiment is colored blue by mixing the resin layer with vanadium zirconium blue as an inorganic pigment.

  In this example, gas chromatography was performed in exactly the same manner as in Example 1 except that the coiled sample collection piece 28 prepared in this example was used. The result is shown in FIG. 5B.

  From FIG. 5B, by using the sampling unit 2 equipped with the coiled sample collection piece 28 prepared in the present embodiment, from the sample adsorbed on the coiled sample collection piece 28, the same a to h of Example 1 are obtained. In addition to the compound, it can be seen that j: 2-heptadecanone and k: heptadecanal are separated in place of i: methyl palmitate.

Example 3
In this example, a silicon coating layer was formed on the surface of a stainless steel coil having an inner diameter of 1 mm and a length of 10 mm, and a mixture of propylene glycol and dimethylpolysiloxane as a resin having medium polarity on the silicon coating layer. A coiled sample collection piece 28 was prepared by forming a 2 μm-thick resin coating layer. The coiled sample collection piece 28 of the present embodiment is colored yellow by mixing chromium titanium yellow as an inorganic pigment in the resin layer.

  In this example, gas chromatography was performed in exactly the same manner as in Example 1 except that the coiled sample collection piece 28 prepared in this example was used. The result is shown in FIG. 5C.

  From FIG. 5C, by using the sampling unit 2 equipped with the coiled sample collection piece 28 prepared in this example, from the sample adsorbed on the coiled sample collection piece 28, the same b to d of Example 1 were obtained. It can be seen that the compounds are separated.

Example 4
In this embodiment, a silicon coating layer is formed on the surface of a stainless steel coil having an inner diameter of 1 mm and a length of 10 mm, and a 2 μm thick resin coating layer made of propylene glycol as a resin having a large polarity is formed on the silicon coating layer. A coiled sample collection piece 28 was prepared. The coiled sample collection piece 28 of the present embodiment is colored black by mixing carbon as an inorganic pigment in the resin layer.

  In this example, gas chromatography was performed in exactly the same manner as in Example 1 except that the coiled sample collection piece 28 prepared in this example was used. The result is shown in FIG. 5D.

  From FIG. 5D, by using the sampling unit 2 equipped with the coiled sample collection piece 28 prepared in this example, from the sample adsorbed on the coiled sample collection piece 28, the same b to d of Example 1 were obtained. It can be seen that the compounds are separated.

  From Examples 1 to 4, according to the sampling unit of the present invention, as the resin coating layer, various components in the sample can be selectively analyzed by properly using resins having different polarities depending on the analysis target. Is clear.

  In the present embodiment, the case where the sample collection piece is a coiled sample collection piece 28 is described. However, the sample collection piece is configured to be detachably attached to the tip of the sample collection rod 26. There is no limitation to the coiled sample collection piece 28.

  DESCRIPTION OF SYMBOLS 1 ... Gas phase component analyzer, 2 ... Sampling unit, 11 ... Heating part, 20 ... Cylinder, 21 ... Plunger, 23 ... Needle, 24 ... Syringe, 26 ... Sampling rod, 28 ... Sampling piece

Claims (4)

A sampling unit that collects a sample introduced into a heating unit of a gas phase component analyzer and vaporizes the sample by being heated in the heating unit,
A sampling rod and a sampling piece;
The sample collection piece includes an undercoat layer that covers and inactivates the surface, and a resin coating layer that covers the surface of the undercoat layer and adsorbs the sample,
A plurality of types of the sample collection pieces having different polarities of the resin forming the resin coating layer are provided, and the sample collection pieces are detachably attached to the tip of the sample collection rod ,
The sampling piece is colored in such a manner that it can be distinguished by an inorganic pigment capable of maintaining its molecular structure when heated by the heating unit for each polarity of the resin forming the resin coating layer. unit.   2. The sampling unit according to claim 1, wherein the sample collection piece is a metal coil, the sample collection rod has a sharp tip, and the metal coil is detachably attached to the tip of the sample collection rod. A sampling unit characterized by 2. The sampling unit according to claim 1 , wherein the inorganic pigment is one or more pigments selected from the group consisting of ceramic pigments, composite oxide pigments, bengara, basic lead chromate, titanium white, zinc white, and carbon. A sampling unit characterized by being. The sampling unit according to claim 3 , wherein the ceramic pigment is a Co-Cr-Fe pigment, a Co-Mn-Fe pigment, an antimony tin gray, a zircon gray, a Zn-Cr-Fe pigment, or a Zn-Al-Cr pigment. -Fe pigment, Napoli yellow, praseodymium yellow, vanadium tin yellow, vanadium zirconium yellow, Zr-Ti-V-In pigment, chromium titanium yellow, Zr-Si-Cd-S pigment, Zr-Y-V pigment , Peacock, Victoria Green, Chrome Green, Cr pigment, Co-Cr pigment, bitumen, ridge, Co-Zn-Si pigment, Co-Si pigment, vanadium zirconium blue, chrome tin lilac, lilac, chrome tin 1 selected from the group consisting of pink, ceramic red, salmon pink, chrome alumina pink, and fire red Sampling unit which is a more pigments.