KR20040034252A - Matrix assisted laser desorption ionization time of flight mass spectrometry - Google Patents

Abstract

PURPOSE: A matrix assisted laser deposition ionization-time of flight mass spectroscopy is provided to improve resolution by fabricating the matrix assisted laser deposition ionization-time of flight mass spectroscopy in a compact size. CONSTITUTION: A matrix assisted laser deposition ionization-time of flight mass spectroscopy includes a light source(101), a main chamber(105), a flight tube(123), and a sub-chamber(129). The light source(101) radiates light onto a test sample so as to dissolve the test sample into ions. A light attenuator(102) is provided in front of the light source(101) in order to attenuate intensity of light. A prism(103) is installed in a light route formed between the light attenuator(102) and the test sample. The prism(103) refracts light toward the test sample so that ions are separated from the test sample.

Description

Matrix assisted laser desorption ionization time of flight mass spectrometry

The present invention relates to a matrix assisted laser detachment time-of-flight mass spectrometer (MALDI-TOF MS), and more particularly to a compact medium assisted laser detachment excitation with high performance resolution. A time-of-flight mass spectrometer.

Medium assisted laser desorption excitation time mass spectrometry (hereinafter referred to as mass spectrometry) is a device that analyzes the mass of polymer biomaterials such as DNA and proteins.

1 is a cross-sectional view showing a conventional mass spectrometer.

Referring to FIG. 1, the laser beam or ultraviolet light emitted from the light source 11 is adjusted by the light intensity while passing through the light attenuator 12 and then refracted by the prism 13 to irradiate the sample S ₀ . Samples (S ₀₎ is transferred to the main source chamber 15 from the sample chamber 19 is mounted on the sample holder 16, the ions from the light samples (S ₀₎ irradiated from the light source (11), (I ₀₎ Remove them. The desorbed ions I ₀ are accelerated in the direction of the electric field due to the electric field formed by the voltage applied to the first grid 17 and the second grid 20, and pass through the flight tube 23 to detect the chamber. 29).

The detection chamber 29 is provided with a linear detector 28 to detect ions traveling straight in the axial direction of the flight tube 23, and a plurality of reflectors 27 are arranged inside the detection chamber 29 to form ions ( I ₀ ) changes to return to the reflective detector 26. Most of the ions I ₀ are changed by the reflector 27 and detected by the reflective detector 26. Reference numeral 20 denotes a collision cell, reference numeral 22 denotes a video camera, reference numeral 24 denotes a beam guide wire, and reference numeral 25 denotes an ion selector.

Conventionally, using a mass spectrometer of the type shown, it was possible to obtain information about the mass (atomic weight to charge ratio) of the ions by measuring the time the ions I ₀ pass through the flight tube. However, the conventional mass spectrometer has a long length of the flight tube provided, so that the total volume of the mass spectrometer is large and thus requires a large installation space. In addition, when the conventional mass spectrometer is provided with a straight flight tube, the mass spectrometer is simple in shape but the mass resolution is inferior. In the case where a curved flight tube is provided, the resolution is improved but a device for applying a separate potential or magnetic field is provided. Has the necessary disadvantages.

Accordingly, the present invention provides a compact medium assisted laser desorption excitation time-of-flight mass spectrometer with improved resolution in order to solve the problems of the prior art.

1 is a block diagram of a conventional medium assisted laser desorption excitation flight time mass spectrometer,

2 is a block diagram of a medium assisted laser desorption excitation flight time mass spectrometer according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

101; Light source 102; Attenuator

103; Prism 105; Main chamber

106; Sample holder 107; First grid

111; Vacuum chamber 113; Second grid

119; Sample chamber 120; Reflective Detector

121; Aperture channel 122; Video camera

127; Reflector 128; Linear detector

129; Subchamber

The present invention to achieve the above technical problem,

Optical system;

And a sample holder on which a sample from which ions are desorbed by a beam irradiated from the optical system is seated, a first grid for accelerating the ions, and a reflective detector for detecting ions passing back after passing through the first grid. Main chamber;

A flight tube which penetrates through the main chamber and in which the ions accelerated in the main chamber fly;

A subchamber including a reflector penetrating the air pipe and changing the path of the ions to return to the main chamber, and a linear detector for detecting ions traveling parallel to the central axis of the air pipe; And

And a main chamber, the flight tube, and a vacuum chamber for maintaining the sub-chamber in a vacuum state.

The main chamber has a second grid that forms an equipotential region around the reflective detector.

The reflector is provided on both side walls of the inside of the subchamber and separates the ions into first and second paths symmetrical with respect to the central axis of the flight tube and returns to the main chamber.

The reflective detector includes first and second detection plates for detecting ions returning to the first and second paths from the subchamber.

The main chamber preferably further includes an opening channel at a connection portion with the flight tube to focus ions returning from the flight tube.

A sample chamber for supplying the sample may be further provided outside the main chamber.

The optical system includes a light source for irradiating a laser beam or ultraviolet light.

The optical system may further include a light attenuator for adjusting the light intensity of the laser beam or ultraviolet light irradiated from the light source.

Mass spectrometer according to an embodiment of the present invention, unlike the conventional mass spectrometer, the resolution is improved by doubling the path by which the ions desorbed from the sample fly about. In addition, in the mass spectrometer according to the embodiment of the present invention, when the ions fly a path having a length similar to that of the conventional mass spectrometer, the mass spectrometer may have a similar resolution to that of the conventional mass spectrometer and may be manufactured in a compact size.

Hereinafter, a medium assisted laser desorption excitation flight time mass spectrometer (hereinafter referred to as a mass spectrometer) according to an exemplary embodiment of the present invention will be described in detail.

2 is a block diagram of a mass spectrometer according to an embodiment of the present invention.

2, a mass spectrometer according to an embodiment of the present invention includes a light source 101, a main chamber 105 penetrating and connected to each other, a flight tube 123, and a sub chamber 129. .

The light source 101 emits light such as a laser beam or ultraviolet light capable of decomposing the sample S into ions, where the light source 101 is assumed to be a laser. The light attenuator 102 is further positioned in front of the light source 101 to mitigate the light intensity of the laser beam to be irradiated. A prism 103 is disposed on the optical path between the optical attenuator 102 and the sample S to deflect the laser beam and irradiate the sample S to desorb ions from the sample S.

The main chamber 105 passes through the sample holder 106 on which the sample S is seated, the first grid 107 for accelerating the ions desorbed from the sample S, and the first grid 107. , A reflective detector 120 for detecting ions I1 and I2 returning to the first and second paths symmetrical with respect to the central axis of the flight tube 123, and a first detector around the reflective detector 120. A second grid 113 is formed by applying a reverse voltage to the grid 107 to form an equipotential region having no potential difference.

The flight pipe 123 penetrates through the main chamber 105 on the left side, and ions accelerated by the electric fields formed by the first and second grids 107 and 113 fly therein.

The subchamber 129 penetrates with the right side of the air duct 123, and among the ions accelerated from the air duct 123, ions Ic flying side by side with respect to the central axis of the air duct 123 are flying. The linear detector 128 to detect is provided inside so that the sample S may be opposed. In addition, inside the subchamber 129, a reflecting mirror that reversely applies an electric field to separate ions I1 and I2 having a predetermined azimuth angle into first and second paths and return them to the main chamber 105 ( 127 is provided on both side walls.

An opening channel 121 is separately provided on the left side of the flight tube 123 to focus and divert incident ions I1 and I2 to the reflective detector 120.

The main chamber 105 is provided with a main chamber 105, a flight pipe 123, and a vacuum chamber 111 for maintaining the subchamber 129 in a vacuum state, and a sample placed on the sample holder 106 ( The sample chamber 119 which supplies S) is connected. Vacuum chamber 111 is provided with a mechanical pump and a turbo molecular pump to obtain a high vacuum through the pumping action of the pumps to increase the internal pressure of the main chamber 105, the flight pipe 123 and the sub-chamber 129 Adjust

The outside of the main chamber 105 may be further provided with a video camera 122 that can monitor the state of the sample (S).

Next, a method of determining the mass (m) of ions using a mass spectrometer according to an embodiment of the present invention will be described.

First, a laser beam or ultraviolet rays are irradiated onto the sample S, and the time t that ions desorbed from the sample S fly from the sample S to the linear detector 128 or the reflective detector 120 is measured. . Mass of ions can be analyzed. The flight time t of the ions may be measured from signals detected by the linear detector 128 and the reflective detector 120. The mass (m) of the ionized sample is approximated to the kinetic energy (E) by applying the potential energy (V) applied to the sample as shown in Equation 1, and the equation (1) is calculated as an equation for the mass (m) of ions. The mass (m) of ions can be obtained as in Equation 2.

The velocity v of the unknown ion in Equation 2 measures the distance x between the sample S and the linear detector 128 or the reflective detector 120, and from the signals of the detectors 128 and 120. The obtained flight time (t) can be obtained by substituting a simple equation such as equation (3).

Substituting the velocity (v) of the ion obtained in Equation 3 into Equation 2, the mass of the sample S to be measured can be known.

The present invention has the advantage that the material to be analyzed in the medium to be mixed and ionized to prevent unnecessary crushing of the material to be analyzed and to analyze the mass of a material such as DNA having high molecular weight with high resolution.

In addition, the present invention, while achieving a resolution similar to the conventional mass spectrometer, the length of the flight tube can be reduced by about half compared to the conventional straight flight tube can be made compact and preferably can also be manufactured to be portable.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. The scope of the invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, the advantages of the medium assisted laser desorption excitation flight time mass spectrometer of the present invention can be manufactured compactly with a resolution similar to that of a conventional mass spectrometer, and have an ion flight path similar to that of a conventional mass spectrometer. The improved resolution allows the analysis of masses of organic materials such as polymer DNA.

Claims (8)

Optical system; And a sample holder on which a sample from which ions are desorbed by a beam irradiated from the optical system is seated, a first grid for accelerating the ions, and a reflective detector for detecting ions passing back after passing through the first grid. Main chamber; A flight tube which penetrates through the main chamber and in which the ions accelerated in the main chamber fly; A subchamber including a reflector penetrating the air pipe and changing a path of the ions to return to the main chamber, and a linear detector for detecting ions traveling parallel to the center axis of the air pipe; And And a vacuum chamber for maintaining the main chamber, the flight pipe, and the sub-chamber in a vacuum state. The method of claim 1, The main chamber has a second grid for forming the periphery of the reflective detector to the equipotential region. The method of claim 2, wherein the reflector, Medium assisted laser desorption excitation flight time provided on both side walls of the subchamber and separating the ions into first and second paths symmetrical with respect to the center axis of the flight tube and returning to the main chamber. Mass spectrometer. The method of claim 3, wherein the reflective detector, And a first and a second detection plate for detecting ions returning from the subchamber to the first and second paths. The method of claim 4, wherein the main chamber, The medium assisted laser desorption excitation time-of-flight mass spectrometer having an opening channel at a connection with the air line to focus ions returning from the air line. The method of claim 1, A medium assisted laser desorption excitation flight time mass spectrometer, further comprising a sample chamber for supplying the sample to the outside of the main chamber. The method of claim 1, The optical system, the medium-assisted laser desorption excitation flight time mass spectrometer, characterized in that it comprises a light source for irradiating a laser beam or ultraviolet light. The method of claim 7, wherein The optical system further comprises a light attenuator for adjusting the light intensity of the laser beam or ultraviolet light irradiated from the light source.