JP2005083788A - Connection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection device easy to hande and allowing free attachment and detachment of a separation column. <P>SOLUTION: This connection device is constituted so as to connect a separation means 1 equipped with the separation column 4 for separating a gas sample at every component and a detection means 2 for detecting the component separated by the separation column 4 in a vacuum state. The connection device 6 is equipped with: a resistance pipe 11 which comprises a long metal capillary tube, of which the inner surface is deactiviated, wound into a coil form and connected to the detection means 2 at one end part 11a thereof while made freely detachable with respect to the separation column 4 at the other end part 11b thereof to suppress the inflow of the open air to the detection means 2 when the separation column 4 is detached; and a holding member 12 for holding the resistance pipe 11 to a coil shape. The holding member 12 is equipped with a housing part 13 housing a resistance body 11 therein to hold the same to a coil shape and connected to the detection means 2 at one end part 14 thereof while made freely detachable with respect to the separation column 4 at the other end part 5 thereof. The metal capillary tube is a deactivated metal capillary tube. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a connection device for connecting a separation column of a gas chromatograph device and a mass spectrometer.

  As one method of gas chromatography, a method using a mass spectrometer as a detection device for detecting a gas component separated by a separation column of a gas chromatograph device is known.

  The mass spectrometer is ionized by irradiating electrons to a gas component separated by the separation column, and the obtained ions are predetermined by an electric field composed of four electrodes to which a magnetic field or a high-frequency voltage is applied. The ions are separated into ions having a mass / charge ratio within a range, and the ion intensity of each ion is detected. The ion intensity is proportional to the relative intensity of ions of each mass, for example, ions having a mass / charge ratio in a predetermined range are collected in a detector, and ions reaching the detector are discharged by the detector. It is detected by generating a current. The inside of the mass spectrometer is maintained at a high temperature of about 300 ° C. in a high vacuum state for ionization of the gas component and detection of ionic strength.

  On the other hand, in the gas chromatograph apparatus, the separation column may be exchanged depending on the analysis target, analysis conditions, and the like. At this time, if the separation column and the mass spectrometer are directly connected, when the separation column is removed, the outside air is maintained in the high temperature under a high vacuum state in the mass spectrometer. There is a risk of sudden inflow and damage to internal devices.

  In order to avoid the above situation, it is necessary to cool the interior of the mass spectrometer to a temperature of 100 ° C. or lower, then remove the separation column and open the interior of the mass spectrometer to the atmosphere. However, when doing so, it is necessary to once cool the inside of the mass spectrometer, open it to the atmosphere, replace the separation column, and then reduce the pressure to a predetermined degree of vacuum again and heat it to a predetermined temperature. There is a problem that it takes a long time before it can be used again.

  Therefore, in order to replace the separation column while maintaining the inside of the mass spectrometer at the high temperature under the high vacuum state, it is possible to prevent outside air from flowing into the mass spectrometer when the separation column is removed. A means to do this is desired.

  Conventionally, as a means for suppressing the outside air from flowing into the mass spectrometer when the separation column is removed, the separation column and the mass spectrometer have an inner diameter of 0.1 to 0.15 mm made of fused silica. Means for connecting by a capillary tube (hereinafter abbreviated as FS capillary tube) are known. Note that the above means are means that are used know-how in research facilities and the like, and since the present inventor has not confirmed the literature in which the means is described, prior art document information to be described in the present specification. There is no.

  According to the means, the FS capillary tube is housed in the thermostat of the gas chromatograph apparatus together with the separation column, connected to the mass spectrometer at one end, and the other end is attached to and detached from the separation column. It is supposed to be free. And when exchanging the separation column, the separation column is removed from the FS capillary tube. In this way, since the FS capillary tube remains connected to the mass spectrometer, the FS capillary tube having the inner diameter becomes a resistance against the outside air that is about to flow into the mass spectrometer, and the inflow of the outside air is reduced. It is suppressed. Therefore, the separation column can be exchanged without damaging the devices while maintaining the inside of the mass spectrometer at the high temperature under the high vacuum state.

  By the way, the FS capillary tube needs a length of about 70 to 150 cm to act as resistance to the outside air to flow into the mass spectrometer, and cannot be accommodated in the thermostat if it remains linear. . For this reason, the FS capillary tube is wound in a loop shape and accommodated in the thermostat.

  However, since the FS capillary tube is hard and brittle, it is limited to a loop shape with a diameter of about 15 to 25 cm, and since it cannot be made smaller than this, the loop shape can be sufficiently downsized. Is difficult. For this reason, the FS capillary tube has an inconvenience that it may become an obstacle or break when the separation column is attached or detached.

  An object of the present invention is to provide a connection device that eliminates such inconvenience, is easy to handle, and does not obstruct the attachment / detachment of a separation column.

  In order to achieve such an object, the connection device of the present invention includes a separation unit that includes a separation column that separates a gas sample for each component, and a detection unit that detects a component separated by the separation column in a vacuum state. In the connecting device to be connected, the long inner surface wound in a coil shape is made of an inactivated metal capillary tube. One end is connected to the detection means, and the other end is detachable from the separation column. And a resistance tube that suppresses the inflow of outside air to the detection means when the separation column is removed, and a holding member that holds the resistance tube in a coil shape.

  In the connection device of the present invention, the resistance tube is formed by winding a metal capillary tube whose inner surface is inactivated in a coil shape, and is connected to the detection means at one end, and the other end is the separation It is detachable from the column. Thus, when the separation column is removed from the metal capillary to replace the separation column, the metal capillary remains connected to the detection means at one end. Accordingly, the metal capillary tube becomes a resistance against the outside air that is about to flow into the detection means, the inflow of the outside air is suppressed, and the separation column is replaced while the inside of the detection means is maintained in the vacuum state. It can be carried out.

  Since the metal capillary is flexible, it can be formed into a small-diameter coil shape, and a long one can be made compact and accommodated in the separating means. However, since the metal capillary is flexible, it cannot hold the coil shape by itself and hangs down due to its own weight, so that it is difficult to handle. Therefore, the connection device of the present invention includes a holding member for holding the resistance tube in a coil shape.

  As a result, according to the connecting device of the present invention, a resistance tube made of a long metal capillary can be made compact and accommodated in the separating means, and the compacted resistance tube can be easily handled. The resistance tube can be prevented from becoming an obstacle to the attachment and detachment of the separation column.

  In the connection device according to the aspect of the invention, the holding member includes a storage portion that stores the resistor and holds the coil shape therein, and is connected to the detection unit at one end, and the other end is The separation column is detachable. As a result, according to the connection device of the present invention, the holding member that holds the coil shape of the resistor can be used for connection to the detection means and a configuration that is detachable from the separation column. .

  In the connection device of the present invention, for example, an inactivated metal capillary tube can be used as the metal capillary tube.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a system configuration diagram of a gas chromatograph-mass spectrometer using the connection device of the present embodiment, and FIG. 2 is an explanatory sectional view showing the connection device of the present embodiment.

  The gas chromatograph-mass spectrometer shown in FIG. 1 includes a gas chromatograph apparatus 1 as a separating means and a mass spectrometer 2 as a detecting means. The gas chromatograph apparatus 1 includes a separation column 4 for separating a gas sample for each component in a thermostatic chamber 3, and the separation column 4 is connected at one end to a sample inlet 5, and the other end is at the thermostatic chamber 3. Is connected to the connection device 6 accommodated in the terminal. The connection device 6 is connected to a hollow cylindrical interface 8 that opens to a position facing the ion source 7 in the mass spectrometer 2.

  As shown in FIG. 2, the connecting device 6 includes a resistance tube 11 made of a metal capillary tube wound in a coil shape, and a holding member 12 that holds the coil shape of the resistance tube 11. The metal capillary tube is made of, for example, an inactivated stainless steel tube and is a very flexible tube. Therefore, even if it is long, it can be made compact by making it into a small coil shape. In this embodiment, the metal capillary tube having an inner diameter of 0.15 mm and a length of 0.8 m is wound in a coil shape having a diameter of 1 cm to form a resistance tube 11 having a total length of 25 cm.

  The holding member 12 has a hollow cylindrical shape, and includes a storage portion 13 for storing the coiled resistance tube 11 therein, an interface connection portion 14 connected to the interface 8 at one end, and a separation column at the other end. 4 is provided with a separation column connecting portion 15 connected to 4. The interface connecting portion 14 is screwed and welded to the distal end portion of the interface 8, and a seal packing 16 is disposed between the distal end portion of the interface 8 and the storage portion 13. A column nut 17 attached to the tip of the separation column 4 can be screwed to the separation column connecting portion 15, and a seal packing is provided between the tip of the column nut 17 and the storage portion 13. 18 is arranged. The separation column 4 extends through the column nut 17 and the seal packing 18 to a position facing the storage unit 13.

  The resistance tube 11 is connected to the mass spectrometer 2 by one end 11 a passing through the seal packing 16 and extending to the inside of the hollow cylindrical interface 8, and the ion source 7 in the mass spectrometer 2. It is open at the position facing. The other end portion 11 b of the resistance tube 11 is an end portion on the separation column 4 side of the storage portion 13 and opens at a position facing the separation column 4. The other end 11 b of the resistance tube 11 is detachably attached to the separation column 4 by a column nut 17 that can be screwed to the separation column connecting portion 15.

  Note that when the components separated by the separation column 4 are guided to the mass spectrometer 2, the interface 8 is cooled between the thermostat 3 and the mass spectrometer 2 and adheres to the inside of the resistance tube 11. In order to prevent this, a heater 19 is disposed on the outer peripheral side of the resistance tube 11.

  Next, the effect | action of the connection apparatus 6 of this embodiment is demonstrated.

  First, in the gas chromatograph-mass spectrometer shown in FIG. 1, the gas sample injected into the sample inlet 5 is guided to the separation column 4 by a carrier gas such as helium supplied to the sample inlet 5. At this time, the gas sample is separated for each component by the separation column 4 accommodated in the thermostat 3 maintained at a predetermined temperature.

  Each component separated by the separation column 4 is guided to an ion source 7 in the mass spectrometer 2 heated to a temperature of about 300 ° C. under a high vacuum state via a connection device 6 and an interface 8, Ionized at source 7. Ions generated by the ion source 7 are separated into ions having a mass / charge ratio within a predetermined range by an electric field composed of four electrodes to which a high-frequency voltage is applied, and are collected by a detector (not shown) and discharged. . As a result, a current proportional to the relative intensity of each mass ion is generated, and the ion intensity of each ion is detected by measuring the current. The ion intensity detected by the detector is output as a chart such as a chromatogram or a pyrogram by processing with a personal computer or the like.

  Next, in the gas chromatograph-mass spectrometer, it is necessary to select an appropriate separation column 4 according to the type of gas sample to be analyzed and analysis conditions, and the separation column 4 is replaced each time. At this time, if the separation column 4 is directly connected to the interface 8, when the separation column 4 is removed, the opening of the interface 8 is exposed to the outside air, and the outside air is in a high vacuum state as described above from the opening. It flows rapidly into the mass spectrometer 2 below. As a result, components such as the ion source 7 provided in the mass spectrometer 2 heated to a temperature of about 300 ° C. in the high vacuum state may be damaged by being oxidized.

  However, in this embodiment, since the separation column 4 is connected to the interface 8 via the connection device 6, it is possible to avoid a situation in which components such as the ion source 7 are damaged when the separation column 4 is replaced. it can.

  In the connection device 6, when replacing the separation column 4, first, the separation column 4 is removed by releasing the screwing of the column nut 17 to the separation column connection portion 15. At this time, the end 11b of the resistance tube 11 is exposed to the outside air, and the outside air flows into the mass spectrometer 2 from the end 11b. However, since the resistance tube 11 has an inner diameter of 0.15 mm and is very thin, it becomes the resistance of the outside air and can suppress the inflow of the outside air into the mass spectrometer 2.

  Therefore, next, the column nut 17 of another separation column 4 is screwed to the separation column connection portion 15, so that the inside of the mass spectrometer 2 is maintained at the high temperature under the high vacuum state, and the separation column 4 Exchanges can be made.

  The resistance tube 11 itself is composed of a very flexible metal capillary tube, and alone, the coil shape cannot be maintained because it hangs down due to its own weight. However, since the resistance tube 11 is housed in the housing portion 13 and held by the holding member 12, the coil shape can be maintained, and the handling becomes easy, which obstructs the replacement of the separation column 4. This can be prevented.

The system block diagram which shows the example of 1 structure of the apparatus using the connection apparatus of this invention. Explanatory sectional drawing which shows the example of 1 structure of the connection apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Separation means, 2 ... Detection means, 4 ... Separation column, 11 ... Resistance tube, 12 ... Holding member, 13 ... Storage part.

Claims (3)

A separation means comprising a separation column for separating a gas sample for each component;
In a connection device for connecting a detection means for detecting a component separated by the separation column under vacuum,
It consists of a metal capillary in which a long inner surface wound in a coil shape is inactivated, and is connected to the detection means at one end, and the other end is detachable from the separation column. A connection device comprising: a resistance tube that suppresses inflow of outside air to the detection means when the is removed; and a holding member that holds a coil shape of the resistance tube.   The holding member includes a storage portion that stores the resistor and holds the coil shape therein, and is connected to the detection means at one end, and the other end is detachable from the separation column. The connecting device according to claim 1, wherein the connecting device is provided.   The connection device according to claim 1, wherein the metal capillary is an inactivated metal capillary tube.

Images