JPS61194349A - Apparatus for connecting liquid chromatograph mass spectrometer - Google Patents

Abstract

PURPOSE:To make it possible to reduce histeresis by preventing the jet of the eluate from a liquid chromatograph from colliding with the inner wall of a desolvation medium, by providing a metal sheet having a small circular hole provided thereto in this side of a desolvation chamber. CONSTITUTION:The eluate from a liquid chromatography 1 is sprayed by three actions of the back pressure of the liquid chromatograph 1, the heating of a pipe 6 by the heater 12 attached to a copper block 7 and the collision with the H2-gas introduced from an nitrogen gas introducing port 8. The jet of the eluate injected from the leading end of a pipe 6 is passed through a metal sheet 10 having a circular hole for removing large mist droplets and a desolvation chamber 11 for promoting desolvation by heating to be formed into fine particles. The mist droplets introduced into an ion source block 13 are ionized by a corona discharge needle electrode 4 and sent to a mass spectrometer 19 through a first porous electrode 16 and a second porous electrode 17 to receive mass spectrometry.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a liquid chromatograph/mass spectrometer coupling device, and particularly to an interface structure suitable for reducing hysteresis at the interface.

[Background of the invention]

A conventional device is shown in FIG. Similar structures have been found in Analytical Chemistry (Anal, Chem), 54, 4.
52 (1982). In this document, a metal plate with a pinhole (10 μmφ) is attached to the tip of a thin tube to atomize the output from a liquid chromatograph.

□In the apparatus shown in FIG. 1, the effluent from the liquid chromatograph 1 passes through the capillary 6 and enters the interface 5. Inside the interface 5, the inner diameter is several tens of μm-w.
A thin tube (SUS pipe 5) of about 1QQ .mu.m is passed through, and by heating this thin tube, the output from the liquid chromatograph 1 is converted to tg. liquid chromatograph l
A portion of the effluent flows through this heated capillary into small mist droplets and is carried to the ion source 40 by nitrogen gas introduced from the nitrogen inlet 8. On the way, the mist droplets pass through a Pyrex-controlled desolvation chamber 11 heated by a heater 12, become smaller and ionized by a corona discharge needle electrode 14, and then subjected to mass spectrometry by a mass spectrometer 20.

In this method, the jet atomized by the thin tube spreads out on the way, and a lot of the mist is transferred to the Pyrex control/desolvation chamber 1.
It collides with the inner wall of No. 1, and the inner wall is heated, but part of it is adsorbed by the wall, and if this gradually comes out, it becomes a major cause of hysteresis.

Furthermore, when many mist droplets (particularly those with large particle diameters) collide with the wall of the desolvation chamber 11, the temperature of the wall decreases. There was a problem in that the capacity of 12 had to be increased.

[Purpose of the invention]

It is an object of the present invention to provide a liquid chromatograph/mass spectrometer coupling device having an interface structure such that the jet of effluent from the liquid chromatograph does not collide with the inner wall of the desolvation chamber as much as possible.

[Summary of the invention]

Since the jet sprayed from the nozzle inevitably spreads out in a conical shape, it often collides with the wall of the desolvation chamber.

Therefore, a button in front of the desolvation chamber and a metal sheet with small circular holes were installed to allow only those jets with small divergence angles to pass through. For this sheet,
After this sheet, the jet becomes a narrowed jet with a smaller solid angle, so the probability of colliding with the wall of the desolvation chamber is considerably reduced.

The configuration of the present invention is as follows in more detail.

A liquid chromatograph for separating a mixed sample, an atomization means for atomizing the effluent from the liquid chromatograph, a desolvation chamber provided behind the atomization means, and a desolvation chamber for the atomization. In a liquid chromatograph/mass spectrometer coupled device consisting of an ion source for ionizing the passing mist droplets and a mass spectrometer section for mass spectrometry analysis of the ions obtained by the ion source, the atomization means and the desolvation material are used. A liquid chromatograph/mass spectrometer coupling device, characterized in that a sheet is provided between the two for restricting the passage of the mist.

[Embodiments of the invention]

An embodiment of the present invention will be explained below with reference to FIG. The effluent from the liquid chromatograph 1 is transferred to the interface 5
It is guided to the SvS vibro welded to the copper block 7 inside. A pump 3 sends solvent from the solvent reservoir 2 to clean the inside of the thin tube 6 in the interface 5. This is switched to the output from the liquid chromatograph 1 by a three-way cock 4. The effluent is caused by the back pressure of the liquid chromatograph 1, the heating of the pipe by the heater 12 attached to the copper block 7, and the nitrogen gas inlet 8.
It is atomized by three actions: collision with the introduced Hz gas. The jet of effluent ejected from the tip of the pipe passes through a metal sheath (10) with circular holes to remove large mist droplets, and a desolvation chamber (11) to accelerate desolvation by heating. The particles are guided into the ion source block 13 in the form of fine particles.

By installing the metal sheet (10) with circular holes, it is possible to introduce only the jet with a small solid angle among the jets with a wide solid angle into the desolvation chamber 11 and prevent it from hitting the side of the desolvation chamber 11. . Therefore, the inner wall of the desolvation chamber is less likely to be contaminated by the sample than if there is no metal sheet, and therefore the history can be reduced. Further, since collisions between the gas and the inner wall of the desolvation chamber 11 are reduced, the temperature of the desolvation chamber 11 is not lowered. Therefore, when the metal sheet 10 is present, the heater capacity of the lip removal medium chamber 1 can be made smaller than when there is no metal sheet.

The third type of metal sheet lO with circular holes is
The cone-shaped one shown in the figure and the hand plate-shaped one shown in FIG. 5 are considered. 4 and 6 show that the liquid atomized by the capillary 6 in the interface 5 passes through the metal sheath 10 to the desolvation chamber 11.
This is a diagram showing the inside of the screen. It can be seen that this makes it difficult for mist droplets to adhere to the inner wall of the desolvation chamber 11.

The mist droplets introduced into the ion source are transferred to the corona discharge needle electrode 14.
It is then ionized, passes through the first pore electrode 16 and the second pore electrode 17, and is sent to a mass spectrometer 19 for mass spectrometry.

〔Effect of the invention〕

According to the present invention, it is possible to prevent the jet from colliding with the inner wall of the desolvation chamber as much as possible, so that hysteresis can be reduced. The situation is shown in Figure 7. Figure (a) shows no metal sheet;
Figure 3) shows the measurements taken using a mass spectrometer in the case of reeds. ), the signal amount is reduced to less than 1 kl/10.

Brief Description of Page 1 FIG. 1 is a diagram showing a conventional frame chromatograph-mass spectrometer coupling device, FIG. 2 is a cross-sectional view of a liquid chromatograph-mass spectrometer coupling device according to the present invention, and FIG. 3 and 5 are diagrams showing a metal sheet with circular holes according to the present invention,
The fourth factor and FIG. 6 are diagrams showing the vicinity of the metal sheet of a liquid chromatograph mass spectrometer coupling device equipped with a metal sheet with circular holes according to the present invention, and FIG. FIG. 2 is a diagram showing a history of measurements made using a liquid chromatograph mass spectrometer coupling device and a liquid chromatograph mass spectrometer coupling device according to the present invention.

l...liquid chromatograph, 2...solvent reservoir, 3.
...Pump, 4...Three-way cock, 5...Interface, 6...SOS pipe, 7...Copper block,
8... Nitrogen gas inlet, 9... Jet spout, l
O...SUE sheet, 11...Desolvation chamber, 12...
・Heater, 13...Ion source block, 14...
Needle electrode for corona discharge, 15... Surplus gas escape port, 16
...first pore electrode, 17...second pore electrode, 18.
...Vacuum pump, 19...Analysis section, 20...Mass spectrometry needle.

Third country Fourth trouble 7th country (Meeting Lee Jujinoshin) (ri) Tomoma E Imama

Claims (1)

[Claims] 1. A liquid chromatograph for separating a mixed sample;
an atomizing means for atomizing the effluent from the liquid chromatograph; a desolvation chamber provided behind the atomizing means;
A liquid chromatograph/mass spectrometer combination device comprising an ion source for ionizing the mist droplets passing through the desolvation chamber and a mass spectrometry section for mass spectrometry of the ions obtained by the ion source. A device for coupling a liquid chromatograph/mass spectrometer, characterized in that a sheet for restricting passage of the mist is provided between the desolvation means and the desolvation material. 2. The liquid chromatograph mass spectrometer coupling device according to claim 1, wherein the sheet is a metal sheet. 3. The liquid chromatograph/mass spectrometer coupling device according to claim 1, wherein the sheet is formed into a hand plate having circular holes or a conical shape. 4. The liquid chromatograph mass spectrometer coupling device according to claim 2, wherein the metal sheet has a hand plate or cone shape with circular holes.