JPH0980038A - Metal capillary column for gas chromatograph and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal capillary column whose metal activity for a gas chromatograph capable of being used continuously at a high temperature is inactivated, which is manufactured without associating with any danger and which is sufficiently flexible and to provide its manufacturing method. SOLUTION: In a metal capillary column for a gas chromatograph, a quartz film which is formed by firing a perhydropolysilazane coating film is formed on the inner wall surface of a metal capillary. In the manufacturing method of the metal capillary column, the inner wall surface of the metal capillary is coated with perhydropolysilazane, the perhydropolysilazane is fired under the existence of oxygen molecules, and the quartz film is produced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a metal capillary column used in a gas chromatograph and a method for producing the same.

[0002]

2. Description of the Related Art A capillary column for a gas chromatograph was initially a metal capillary column, but its inner wall has a function of adsorbing an analytical sample component, that is,
The metal activity was so great that it could hardly be put to practical use. 19
Glass capillary columns were used in the 1960s. After that, a fused silica capillary column was proposed, which has excellent characteristics such as ease of handling due to its flexibility, and the degree of deactivation for non-polar components and polar components (Japanese Patent Publication Sho 6).
2-228160), the glass capillary column has been widely used instead of the column.

An example of this fused silica capillary column is an inner diameter of 0.25 mm and a quartz wall thickness of about 40 μ.
m, the outer surface of which is covered with a polyimide film or an aluminum coating layer is new enough to be wound around a cylinder having a diameter of 5 cm, and the outer surface of which is covered with a polyimide film. Has a heat resistance such that it can withstand the maximum operating temperature of 350 ° C. in a short time, and that the product coated with the aluminum coating layer can withstand the maximum operating temperature of 380 ° C. in a short time.

However, the fused silica capillary column described above is prone to breakage during use, especially 30
When it is continuously used at 0 ° C or higher, the frequency of this breakage increases, and at 380 ° C or higher, the coating material on the outer peripheral surface deteriorates significantly, and even after a short time, the capillary column is not broken and the gas chromatograph does not occur. Difficult to remove from the tograph. This is the bottleneck of the gas chromatograph method in the high temperature region.

On the other hand, as a capillary column that can be continuously used at high temperature, a method of oxidizing the inner wall surface of a metal capillary, thermally decomposing monosilane gas in the metal capillary, and coating the inner wall surface with metallic silicon (Wada) Hirotaka Master's Thesis Takayama Laboratory, Toyohashi University of Technology 1987 3
Month; Y. Takayama, T .; Takeichi,
J. Chromatogr. A685 (1994) 6
The capillary column obtained by deactivating the metal activity obtained in 1) has been put to practical use, and the metal activity was deactivated by a method presumed that the inner wall surface of the metal capillary was coated with sol-gel glass. Metal capillary columns are also commercially available.

These metal capillary columns whose inner wall surfaces are coated with metallic silicon, and commercially available metal capillary columns which are presumed to have their inner wall surfaces coated with sol-gel glass, all exhibit metal activity on the inner wall surface of the capillary column. The degree of deactivation is sufficient, and the former inert metal capillary column whose inner wall surface is coated with metallic silicon has sufficient performance in terms of flexibility.

However, in the former case, that is, in the metal capillary column whose inner wall surface is coated with metallic silicon, the monosilane gas used as a treating agent when the inner wall surface of the metal capillary is inactivated, that is, when coated with silicon is a dangerous substance. Therefore, it can be manufactured only in the place where the monosilane gas handling regulation has passed, and even in the place where the monosilane gas handling regulation has passed, the danger of explosion caused by monosilane gas and the white powder near the outlet of the monosilane gas cylinder It is necessary to pay close attention to prevent the occurrence, and it has a problem in manufacturing.

In the latter case, a commercially available metal capillary column whose inner wall surface is presumed to be coated with sol-gel method glass is rolled into a circle with a diameter of 5 cm or less, for example, and the glass film coating the inner wall surface peels off and falls off. Since the metal is exposed at that portion, the degree of metal deactivation of the inner wall surface cannot be maintained, and the flexibility is not sufficiently satisfactory.

That is, in the case where the inner wall surface of the metal capillary is coated with glass by applying the sol-gel method, a specific bonding state is not generated between the inner wall surface of the metal capillary and the glass film, and further, the gel is not formed. Since the organic components such as methoxy groups are scattered during the firing of the film, the resulting glass film has a low degree of compactness, and since it is in a crunchy state, it lacks flexibility and the metal capillary column is wound around a small diameter cylinder. At the time of application, a crack is generated in the glass film and falls off, which causes a problem that the degree of inactivation of the inner wall surface cannot be maintained.

[0010]

Therefore, an object of the present invention is a metal capillary column in which the metal activity has been deactivated for a gas chromatograph which can be continuously used at a high temperature, and there is a danger in the production thereof. Without
An object of the present invention is to provide a metal capillary column which is inactive and has sufficient flexibility, and a method for producing the same.

[0011]

The above object can be achieved by a metal capillary column for a gas chromatograph and a method for producing the same according to the present invention having the following constitution.

[0012] In the course of the present inventors' previous research on a metal capillary column in which the metal activity was inactivated by the silicon coating of monosilane pyrolysis, the capillary column was not used again at the high temperature for a long time without exhibiting the metal activity. In order to withstand, for example, Si—O—Me (Me: metal) is formed between the produced silicon and the oxide on the inner wall of the metal capillary.
I noticed that it is necessary to have some kind of bond. It is necessary that the silicon atom that forms such a bond is a so-called nascent one, which is generated by the thermal decomposition of some raw material compound. Further, in order to avoid the shape defect of the generated coating film, it is desirable that the raw material to be the source thereof contains as little organic component as possible. The produced coating film must be a silicon film or a glass material, and if possible, a glass material containing no metal, based on the conventional knowledge. As a result of various studies on raw materials satisfying these conditions, perhydropolysilazane was selected and the present invention was completed.

That is, according to the present invention, a metal film for a gas chromatograph having a quartz film formed by firing a coating film of perhydropolysilazane on the inner wall surface of a metal capillary in the presence of oxygen molecules is inactivated. It consists of a metal capillary column.

Further, according to the present invention, after applying perhydropolysilazane on the inner wall surface of the metal capillary, the perhydropolysilazane is fired in the presence of oxygen molecules so that a metal film for a gas chromatograph which produces a quartz film is not activated. The method comprises the production of an activated metal capillary column.

Further, according to the present invention, a pretreatment for oxidizing the inner wall surface of the metal capillary is performed, and then the inner wall surface is coated with perhydropolysilazane, followed by firing the perhydropolysilazane in the presence of oxygen molecules. It comprises a method for producing a metal capillary column in which a metal activity for a gas chromatograph for producing a quartz film is inactivated.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In the metal capillary column for a gas chromatograph and the method for producing the same according to the present invention having the above-mentioned structure, the type of metal capillary used is not particularly limited as long as it is flexible. However, considering the price and the usage of the metal capillary column, the stainless steel column is most preferable.

The hole diameter of the metal capillary is not particularly limited, either, but the inner diameter is about 0.1 to 2.0 mm, and especially 0.1.
It is preferably about 25 to 0.8 mm. The length of the metal capillary is about 5 to 100 m.

Before the perhydropolysilazane is applied to the inner wall surface of the metal capillary, the treatment on the inner wall surface of the metal capillary is usually performed only by washing with an organic solvent to remove foreign matters. It should be noted that the cleaning may be performed to the extent that the inner wall surface of the metal capillary is chemically polished, but this has no particular advantage.

However, if the inner wall surface of the metal capillary is pre-oxidized prior to the coating and firing of the perhydropolysilazane, the uniform application of the perhydropolysilazane to the inner wall surface will be facilitated, and the perhydropolysilazane will be produced by firing. Between the quartz film and the inner wall surface of the metal capillary, Si-
Since the bond by O-Me is generated, the bond strength of the quartz film to the inner wall surface of the metal capillary becomes higher. Therefore, the peeling resistance of the quartz film when the metal capillary column is wound in a circular shape becomes higher.

The application of perhydropolysilazane to the inner wall surface of the metal capillary is performed using a solution of perhydropolysilazane. As perhydropolysilazane,
Although those having a number average molecular weight of 600 to 2000 are commercially available, any of them may be used. As a solvent for diluting perhydropolysilazane, a solvent which does not react with perhydropolysilazane and has high volatility, for example, xylene is most suitable. As a solution of perhydropolysilazane to be applied to the inner wall surface of the metal capillary,
It is preferable to use one in which the metal and water are not present in the solution.

That is, the metal acts as a metal ion, that is, a solid acid in the quartz film and causes adsorption. For this reason,
The metal in the perhydropolysilazane solution applied to the inner wall surface of the metal capillary adversely affects the degree of metal deactivation of the obtained metal capillary column.

Since water in the perhydropolysilazane solution has a function of hydrolyzing perhydropolysilazane, a dehydrated solvent may be used as a solvent for diluting commercially available perhydropolysilazane. desirable. The trace amount of water in the perhydropolysilazane solution causes the presence of silanol groups or cyclosiloxanes in the generated quartz film, which must be inactivated by a known additional deactivation treatment for silanol groups. Therefore, it is not necessary to pay attention to the presence of the above metal.

The application of the perhydropolysilazane solution to the inner wall surface of the metal capillary can be carried out by a dynamic method or a static method, similar to the liquid phase application method for obtaining the metal capillary column. If a quartz film having a thickness of 0.1 μm or more is formed on the inner wall surface of the metal capillary, the metallic property of the inner wall surface can be completely shielded, and a quartz film having a thickness of 2 μm or less can be obtained. If so, the flexibility of the metal capillary is not impaired. The thinner limit of the quartz film cannot be unequivocally expressed because some irregularities are recognized on the metal inner wall that is the base of the quartz film.
Also, the thicker limit is 2 to 3 μm because it becomes difficult to form a film without cracks when the thickness exceeds 3 μm. Therefore, the above-mentioned perhydropolysilazane solution is applied to the inner wall surface of the metal capillary so as to obtain a quartz film of 0.1 to 2 μm.

Since the shrinkage ratio in the thickness direction due to firing of perhydropolysilazane is about 30%, it is 0.1
The perhydropolysilazane solution may be applied so that a dry coating film of perhydropolysilazane of about 4 μm to 2.9 μm can be obtained.

In order to obtain a dry coating film of perhydropolysilazane having a desired thickness on the inner wall surface of the metal capillary, the perhydropolysilazane solution coating method by the static method is preferably used. It requires skill and time to operate. On the other hand, the coating method of the perhydropolysilazane solution by the dynamic method does not require skill or time for its operation,
It is difficult in principle to know the thickness of the obtained dry coating film. However, the experience of conventional liquid phase coating when converting a capillary into a capillary column can be used to estimate the thickness of the resulting dry coating film.

For example, in a hole of a metal capillary having an inner diameter of 0.25 mm, about 3% by weight of a perhydropolysilazane solution is filled into the metal capillary at about 1 of the entire length.
By injecting as a 0% length plug and then injecting nitrogen gas, the inside of the metal capillary was moved at a speed of 2 cm / sec from one end of the metal capillary and was discharged from the other end of the metal capillary. After that, when nitrogen gas is still flowed to remove the solvent, a dry film of perhydropolysilazane having a thickness of about 0.2 μm is obtained.

The firing of the coating film of perhydropolysilazane formed on the inner wall surface of the metal capillary is carried out in the presence of oxygen molecules. That is, most commonly, the temperature is raised from room temperature to about 100 ° C. while passing oxygen or dry air, and firing is performed. The quartz film obtained by firing a dry coating film of perhydropolysilazane in the presence of oxygen molecules is bonded to the inner wall surface of the metal capillary via an oxide or via the adsorbed water on the inner wall surface of the metal capillary. It is estimated that Moreover, the quartz film obtained by this firing has a density close to that of fused quartz.

The conversion of the perhydropolysilazane coating film to the quartz film is completed at about 350 ° C., but the working temperature of the metal capillary column obtained by applying the liquid phase to the inner wall surface of the metal capillary is sometimes 450. Since the temperature of the perhydropolysilazane is about 500 ° C., it is desirable that the final stage of baking the coating film of perhydropolysilazane is 500 to 600 ° C. for 0.5 to 5 hours. Can be increased.

However, in the metal capillary having a quartz film formed by firing on the inner wall surface of the above-mentioned capillary, the adsorption action of the metal on the inner wall surface is shielded by the presence of the quartz film covering the inner wall surface of the capillary. As a result, a metal capillary with deactivated metal activity is obtained.

A liquid phase is applied to the above metal capillaries to obtain the metal active deactivated metal capillary column of the present invention. The type of liquid phase, the method of selecting the thickness of the coating film, and the coating method are no different from the conventional knowledge technology of liquid phase coating on glass capillaries. When applying a polar liquid phase to the deactivated metal capillary, a pretreatment is required on the quartz film covering the inner wall of the metal capillary prior to applying the liquid phase in order to ensure the uniformity of the coating film. Sometimes. Here too, the knowledge known in the case of glass capillaries is directly useful. For example, when applying medium polarity OV-17 (50% phenylmethylpolysiloxane, manufactured by Ohiovalu Co., USA) as a liquid phase, first, diphenyltetramethyldisilazane (DPTMDS) is applied to the inner wall of the metal capillary. After ventilation for about 1 hour, seal both ends of the capillary and hold at 300-400 ° C for 10
After heat treatment for ˜15 hours, the mixture is allowed to cool and opened, the inside of the capillary is washed with methylene chloride, and then the liquid phase is applied.

Further, as another example, when polar polyethylene glycol 20M is applied as the liquid phase, W.I. A.
Aue et al. (J. Chromatogr., 77 (197).
3) 299. The pretreatment is carried out by a modified method of the baking method considered in (1). That is, polyethylene glycol
20M 5% methylene chloride solution was applied to the inner wall of the capillary by the dynamic method, both ends of the capillary were sealed, kept at 280 ° C. for 10 hours, allowed to cool, opened, and washed with methylene chloride to wash polyethylene glycol. -Le
Apply 20M. A non-polar liquid phase such as OV-1 (100% dimethylpolysiloxane, manufactured by Ohio Valu USA) does not require pretreatment for liquid phase coating as in the case of glass capillaries.

As in the case of the glass capillary, the column in which the non-polar liquid phase is applied to the capillary in which the metal activity is deactivated is completely insensitive to paraffin which is a non-polar component in the sample passing through it. Although it is active, it still exhibits considerable activity against components such as alcohol, which is a polar component. This is not the action of the metal on the inner wall surface of the metal capillary, but the silanol group (Si-) on the surface of the quartz film formed on the inner wall surface of the metal capillary.
OH). If necessary, it is desirable to inactivate the silanol by utilizing the technology of the glass capillary column, but the operation is not a constituent of the present invention.

In the metal capillary column for a gas chromatograph of the present invention having the above-mentioned structure, a quartz film obtained by firing perhydropolysilazane is formed on the inner wall surface of the metal capillary, and the quartz film is contained in the metal capillary. It is presumed that they are bonded to the wall surface via an oxide or via the adsorbed water on the inner wall surface of the metal capillary.

The perhydropolysilazane used in the method for producing a metal capillary column for a gas chromatograph of the present invention is a substance stable in the atmosphere,
The quartz film obtained by firing perhydropolysilazane has excellent heat resistance and compactness because it has an i-H bond and no organic substance is bonded to the silicon atom.

Moreover, since the above-mentioned perhydropolysilazane is a non-polar substance, regardless of whether or not an oxide is present on the inner wall surface of the metal capillary, the non-polar material used in obtaining a conventional capillary column is used. By applying the perhydropolysilazane solution in the same manner as in forming the liquid phase, stable and uniform application can be performed on the inner wall surface of the metal capillary. Therefore, it is possible to form a coating film of perhydropolysilazane without being repelled on the inner wall surface of the metal capillary, and thereby a metal capillary whose inner wall surface is covered with a quartz film without leaving any residue can be obtained.

Further, the quartz film obtained by firing perhydropolysilazane is different from metallic silicon produced by decomposition products of monosilane gas, and does not necessarily have Si—O—Me bonding through the metal oxide on the inner wall surface of the metal capillary. Since it is not necessary, the preliminary step of oxidizing the inner wall surface of the metal capillary prior to the firing step of perhydropolysilazane may be omitted.

The degree of activity of the column becomes more remarkable as the thickness of the liquid phase becomes thinner. Therefore, the activity test needs to measure the thickness = 0, that is, the state before applying the liquid phase, that is, the degree of activity of the capillary. The measuring method was based on the so-called polarity test method described in the above-mentioned report by the present inventors. This method is a gas chromatogram (a) of a sample solution containing hydrocarbons as a non-polar component and alcohols as a polar component in a dimethylpolysiloxane-coated capillary column in which both metal activity and silanol activity are inactivated. ) Is measured. Next, the capillary column is used as a leading column, and then a test capillary whose activity is to be measured is connected, and the gas chromatogram (b) of the same sample is measured under the same conditions as in the above measurement of the gas chromatogram. [I] Chromatogram (a),
If the peak shapes of the hydrocarbons are almost the same in comparison with (b), the metal activity of the test capillary is sufficiently inactivated. [II] If the peak shape of hydrocarbons in the gas chromatogram (b) is different from that in (a), it is judged that the metal activity is not inactivated. In addition, in the above [I], the shape comparison of the peaks of the polar component shows the residual activity of the silanol.

[0038]

EXAMPLES The specific configurations of the metal capillary column for a gas chromatograph and the method for producing the same according to the present invention will be described below based on production examples. The polarity test performed on the metal capillaries according to the examples and comparative examples and the metal capillary columns using the metal capillaries was performed by the following method.

First, (1) 2,3-butanediol, (2)
n-butyric acid, (3) 2,6-dimethylphenol, (4) 2,
6-dimethylaniline, (5) 1-decanol, (6) n-
1/2000 (g / g) of each of eight kinds of components consisting of tridecane, (7) n-tetradecane, and (8) n-heptadecane
(ml) mixed sample of n-hexane was prepared.
In addition, as a so-called head column (A) connected to the tip of the test metal capillary, a stainless steel capillary obtained by a monosilane gas pyrolysis method was further deactivated with silanol by octamethylcyclotetrasiloxane (D ₄ ), and then dimethylpolyene Thickness of siloxane 0.25
An inner diameter of 0.25 mm and a length of 25 formed by forming a liquid phase of μm
m metal capillary column was used.

A gas chromatogram (a) of the above-mentioned mixed sample by using the head column (A) alone, and a gas chromatogram (b) of the above-mentioned mixed sample by connecting a test metal capillary (B) to the end of the head column (A). ) Was measured respectively. The measurement conditions are as follows: initial temperature 60 ° C, temperature rising rate 3
° C / min, nitrogen as carrier gas linear velocity 40 cm
/ Sec, sample injection amount 1 μl, split ratio 1/80. The shape of each of these chromatograms (a) and (b) is compared for each peak of each component in the mixed sample. The degree of deactivation of the test metal capillaries was judged by this polarity test. The chromatogram obtained by the polarity test using the head column (A) alone is shown in FIG.

[Example 1] Inner diameter 0.25 mm, outer diameter 0.
10 ml of acetone, 10 ml of chloroform and 10 ml of methanol were sequentially passed through the holes of a stainless steel capillary having a length of 63 mm and a length of 10 m to wash the inner wall surface, and then nitrogen was passed through to dry. Then, at the tip and the end of the above-mentioned capillary, respectively, an inner diameter of 0.25 mm and an outer diameter of 1.2 m.
A glass capillary with a length of m and a length of 2.5 m was connected with a heat-shrinkable polyethylene pipe.

Then, a 2% xylene solution (g / ml) of high-purity perhydropolysilazane (manufactured by Tonen Co., Ltd., high-purity product) was injected into the inside of one of the glass capillaries to a length of 1 m, and plugged. The above plug was moved at a speed of 2 cm / sec in the hole of the stainless steel capillary by injecting dry air, and the remaining plug was discharged from the other glass capillary.

After that, the linear velocity of the dry air is changed to 50 cm /
It was left for 90 minutes in a state of about 2 seconds to scatter the xylene remaining on the inner wall surface of the capillary, and the glass capillary was removed to obtain a stainless steel capillary having a coating film of perhydropolysilazane on the inner wall surface.

Then, the above stainless steel capillary was placed in an electric furnace, and the temperature was raised from 110 ° C. to 475 ° C. over 2 hours while passing dry air through the holes of the capillary at a linear velocity of about 50 cm / sec. After that, the temperature was maintained for 2 hours and then allowed to cool to obtain a stainless steel capillary having a quartz film formed on the inner wall surface. Let this stainless steel capillary be a metal capillary (B ₁ ).

A chromatogram (b ₁ ) obtained by the polarity test with the metal capillary (B ₁ ) connected to the end of the head column (A) is shown in FIG. As is clear from the comparison of [Fig. 2] to [Fig. 1], the metal capillary (B ₁ ) is attached to the head column (A).
The chromatogram (b ₁ ) obtained by ligating with, that is, [FIG. 2] shows that the metal capillary (B ₁ ) is in the mixed sample.
It is shown that the metal activity is inactivated for the paraffins of (6) to (8). 1-decanol etc.
The polar components (1) to (5) still have a considerable residual activity, which is due to the activity of silanol.

A 5% solution of polar liquid phase polyethylene glycol 20M in methylene chloride was applied to the metal capillary (B ₁ ) by a dynamic method, and then nitrogen gas was passed through the capillary at 230 ° C. while passing a nitrogen gas at a linear velocity of 10 cm / sec. For 2 hours, at 260 ° C. for 3 hours, and then at 280 ° C. for 4 hours, and allowed to cool. The pretreated metal capillary (B ₁ ) before coating with the liquid phase was subjected to a static method by polyethylene glycol so that the thickness of the liquid phase was 0.3 μm.
A metal capillary column in which the metal activity was made inactive by coating with 0M was prepared. The chromatogram obtained by performing the polarity test with this column alone is shown in FIG. The measurement conditions are the same as described above except that the temperature rising rate is 1 ° C./min, the linear velocity of nitrogen is 18 cm / sec, and the sample injection amount is 1.9 μl.

In FIG. 3, the peaks of the polar components (1) to (5) are as normal as those of the nonpolar components (6) to (8), as compared with the case of FIG. At the stage of the capillary (B ₁ ), the residual activity due to the existing silanol has disappeared. This is a polyethylene glycol 20 at the silanol active site.
It seems that M is coordinated. That is, if a polar liquid phase is used as the liquid phase, it is apparent that a general-purpose useful column can be obtained by the present invention.

Further, after winding the above-mentioned metal capillary column around a cylinder having a diameter of 3 cm, and rewinding this, a diameter of 13 cm which is the size of a normal capillary column is wound.
When repolarized into a circle and subjected to a polarity test, a chromatogram indistinguishable from [Fig. 3] was obtained.

[Embodiment 2] Inner diameter 0.25 mm, outer diameter 0.
Acetone, chloroform, and methanol were sequentially passed through the holes of a 63 mm stainless steel capillary with a length of 10 m, 10 ml each, to wash the inner wall surface, and then heated at 250 ° C. for 1 hour while passing oxygen through the inner wall surface. Oxidized

Then, in the hole of the above-mentioned stainless steel capillary, the same 7% xylene solution of perhydropolysilazane as used in Example 1 (g / ml) was used in the same manner as in the corresponding step of Example 1. Was applied by a dynamic method to apply perhydropolysilazane, and then the same baking step as the corresponding step of Example 1 was carried out.

However, the baking of the coating film of perhydropolysilazane in the electric furnace takes 2 hours from 110 ° C. to 550 ° C.
After the temperature was raised to 0 ° C., the temperature was maintained for 2 hours. This stainless steel capillary is referred to as a metal capillary (B ₂ ). Metal capillary (B ₂ )
The chromatogram (b ₂ ) obtained by the polarity test with the column connected to the end of the head column (A)
It is shown in FIG.

As is clear from the comparison of [FIG. 4] with [FIG. 1], the metal capillaries (B ₂ ) are inactive against the paraffins (6) to (8) in the mixed sample. That is, the metal capillary (B ₂ ) shows that the metal activity is inactivated.

The non-polar liquid phase OV-1 was applied to the above-mentioned metal capillary (B ₂ ) by the static method so that the thickness of the liquid phase became 0.25 μm, and the metal activity according to the present invention was deactivated. A capillary column was manufactured. The chromatogram obtained by performing the polarity test of this column alone did not change the shape of each peak as shown in FIG.
This column is useful for chromatogram measurement of non-polar sample components. However, the measurement of polar components requires a known additional inactivation treatment to inactivate the silanol activity.

In addition, the above metal capillary column is
After winding on a cylinder having a diameter of 3 cm, and then rewinding the same, the process was repeated 5 times, and then rewound to a circle having a diameter of 13 cm, which is the size of a normal capillary column, and a polarity test was performed. ] And the shape of each peak did not change. That is, it was determined that the quartz film on the inner wall was not broken and dropped.

[Comparative Example 1] Inner diameter 0.25 mm, outer diameter 0.
Acetone, chloroform, and methanol were sequentially passed through the holes of a stainless steel capillary having a length of 63 mm and a length of 10 m, 10 ml each, to wash the inner wall surface, and then nitrogen was passed through to dry to obtain a metal capillary (C).

A polarizability test was conducted on this metal capillary (C) connected to the end of the head column (A). As a result, a chromatogram (c) shown in FIG. 5 was obtained.
was gotten. From the chromatogram shown in [Fig. 5], according to the metal capillary (C), the paraffins (6) to (8) in the mixed sample which are not affected by the inner wall surface of the ordinary glass capillary or fused silica capillary are shown. But
It is clear that the metal is heavily activated.

[0057]

Industrial Applicability The metal capillary column for gas chromatograph of the present invention has a thin and dense quartz film formed on the inner wall to block the activity of the metal so as to be inactivated, and the continuous gas chromatography at high temperature. It has heat resistance that can be used for graphography. Moreover, since the quartz film has sufficient flexibility, it eliminates the bottleneck of the gas chromatographic method in the high temperature region of the conventionally used fused silica capillary column, and its practicality is extremely high.

Further, in the method for producing a metal capillary column for a gas chromatograph of the present invention, perhydropolysilazane, which is excellent in stability in air, is applied and fired, so that there is no danger of explosion or the like. It is possible to operate stably without being accompanied. Further, the method of the present invention is not subject to legal restrictions on the manufacturing site because it does not use monosilane.

[Brief description of drawings]

FIG. 1 is a chromatogram (a) obtained by a polarity test using a head column (A) alone.

FIG. 2 is a chromatogram (b ₁ ) obtained by a polarity test of the metal capillary (B ₁ ) of Example 1 connected to the end of the head column (A).

FIG. 3 is a chromatogram obtained by the polarity test of a polar column polyethylene glycol 20M made from a metal capillary (B ₁ ).

FIG. 4 is a chromatogram (b ₂ ) obtained by a polarity test of the metal capillary (B ₂ ) of Example 2 connected to the end of the head column (A).

FIG. 5 is a chromatogram (c) obtained by a polarity test of the metal capillary (C) of Comparative Example 1 connected to the end of the head column (A).

[Explanation of symbols]

 1 2,3-butanediol 2 n-butyric acid 3 2,6-dimethylphenol 4 2,6-dimethylaniline 5 1-decanol 6 n-tridecane 7 n-tetradecane 8 n-heptadecane

Claims (3)

[Claims] 1. A metal capillary column for a gas chromatograph, characterized in that a quartz film formed by firing a coating film of perhydropolysilazane in the presence of oxygen molecules is formed on the inner wall surface of the metal capillary. 2. A metal capillary column for a gas chromatograph, which comprises applying perhydropolysilazane to the inner wall surface of a metal capillary and then calcining the perhydropolysilazane in the presence of oxygen molecules to produce a quartz film. Manufacturing method. 3. A quartz film is formed by subjecting an inner wall surface of a metal capillary to a pretreatment for oxidation, then coating the inner wall surface with perhydropolysilazane, and then calcining the perhydropolysilazane in the presence of oxygen molecules. A method for producing a metal capillary column for a gas chromatograph, which is characterized in that it is produced.