SAMPLE PREPARATION DEVICE FOR MALDI AND SAMPLE PREPARATION METHOD

• US 20130171349A1
• Filed: 11/12/2012
• Published: 07/04/2013
• Est. Priority Date: 12/02/2011
• Status: Active Grant

• Current Assignee: Shimadzu Corporation
• Original Assignee: Shimadzu Corporation
• Inventors: OGAWA, Kiyoshi, TAKAHASHI, Kazuteru
• Granted Patent: US 9,334,569 B2
• Time in Patent Office: Days
• US Class Current: 427/255.23
• CPC Class Codes: C23C 14/12 Organic material
• CPC Class Codes: C23C 14/24 Vacuum evaporation
• CPC Class Codes: C23C 14/54 Controlling or regulating the coating process
• CPC Class Codes: C23C 14/547 using optical methods
• CPC Class Codes: C23C 14/548 Controlling the composition
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: G01B 11/0625 with measurement of absorption or reflection

Abstract

To provide a sample preparation device that is appropriate for the formation of a matrix film for MALDI through vacuum vapor deposition. A sample preparation device is provided with: a sample substrate support unit 23 for supporting a substance to be analyzed on a substrate S so that the substance faces a vapor deposition source 21 for a matrix substance J; a light amount measurement unit for irradiating a matrix film vapor deposited on the substrate S with measurement light diagonally and detecting the amount of measurement light that has transmitted through or has been reflected from the above-described matrix film diagonally; and an adhesion prevention means 23a for preventing the matrix substance that has flown off from the above-described vapor deposition source 21 from adhering to the above-described light amount measurement unit.

Claims

1. A sample preparation apparatus for preparing a sample to be analyzed using a matrix assisted laser desorption/ionization method by forming a matrix film through vacuum vapor deposition at least on a substance to be analyzed on a sample substrate to which the substance to be analyzed is pasted, characterized by comprising:

a vapor deposition source for heating a matrix substance within a vacuum container so that the matrix substance is vapor deposited;

a sample substrate support unit for supporting the sample substrate so that the subject to be analyzed on said sample substrate faces said vapor deposition source;

a light amount measurement unit made up of a light source, which is provided within said vacuum container and diagonally irradiates the matrix film vapor deposited on said sample substrate with light for measurement, and a light detector for detecting the amount of light for measurement that has diagonally transmitted through or has been reflected from the matrix film vapor deposited on said sample substrate; and

an adhesion prevention means for preventing the matrix material that has flown off from said vapor deposition source from adhering to said light amount measurement unit.

2. The sample preparation device according to claim 1, wherein

said sample substrate support unit is formed of a support plate where an opening through which the substance to be analyzed on said sample substrate faces said vapor deposition source is provided,

said support plate is formed so as to work as an adhesion prevention plate in such a manner that the matrix substance from said vapor deposition source is prevented from coming around to the space on the side opposite to said vapor deposition source with the support plate in between when said sample substrate is placed on said opening, and

said support plate works as an adhesion prevention means for said light source or said light detector in the case where the light source or the light detector in said light amount measurement unit is provided in said space on the opposite side.

3. The sample preparation device according to claim 1, wherein an adhesion prevention plate made of a cover for covering the outside of the light source of said light amount measurement unit or said light detector, except for a surface through which light is emitted from the light source or a surface through which light enters into the light detector, and a number of aperture members that are arranged in front of the surface through which light is emitted from the light source or in front of the surface through which light enters into the light detector so that small holes in the aperture members are aligned in series in a coaxial manner, is used as an adhesion prevention means for the light source or said light detector.

4. The sample preparation device according to claim 1, wherein one of said light source and said light detector is provided on the vapor deposition source side of said sample substrate support unit, and the other is provided on the side opposite to the vapor deposition source with said sample substrate support unit in between so that the amount of light that has transmitted through said matrix film is detected.

5. The sample preparation device according to claim 1, wherein said light source and said light detector are both provided on the vapor deposition source side of said sample substrate support unit or are both provided on the side opposite to the vapor deposition source with said sample substrate support unit in between so that the amount of light reflected from said matrix film is detected.

6. The sample preparation device according to claim 1, comprising:

a film thickness reference information storing unit for storing film thickness reference information for finding the film thickness from the amount of light that has transmitted through or that has been reflected from the matrix film by measuring the relationship between the film thickness of the matrix film vapor deposited on said sample substrate and the amount of light that has transmitted through or that has been reflected from the matrix film; and

a film thickness control unit for controlling the film thickness of a matrix film to be formed on the sample substrate by allowing said light amount measurement unit to measure the amount of light that has transmitted through or that has been reflected from the matrix film being vapor deposited on the sample substrate and by controlling the degree of heating of said vapor deposition source on the basis of the measured amount of light and said film thickness reference information.

7. A sample preparation device for preparing a sample to be analyzed using a matrix assisted laser desorption/ionization method by forming through vacuum vapor deposition, at least on a substance to be analyzed on a sample substrate to which the substance to be analyzed is pasted, a matrix film where two types of matrix substances A and B (here, the transmittance TAa of a single substance film of the matrix substance A is higher than the transmittance TBb of a single substance film of the matrix substance B) are mixed, comprising:

two vapor deposition sources for independently heating said two types of matrix substances A and B within a vacuum container so that the matrix substances A and B are vapor deposited;

a sample substrate support unit for supporting the sample substrate so that the substance to be analyzed on said sample substrate faces both of said two vapor deposition sources;

a light amount measurement unit made up of a light source, which is provided within said vacuum container and diagonally irradiates the matrix film vapor deposited on said sample substrate with light for measurement, and a light detector for detecting the amount of light for measurement that has diagonally transmitted through or has been reflected from the matrix film vapor deposited on said sample substrate; and

an adhesion prevention means for preventing the matrix substances A and B that have flown off from said two vapor deposition sources from adhering to said light amount measurement unit, characterized in that

said light amount measurement unit has the light source using light with a certain wavelength that transmits through the matrix substance A, and at the same time is absorbed by the matrix substance B.

8. A sample preparation method for preparing a sample to be analyzed using a matrix assisted laser desorption/ionization method, wherein the sample preparation unit according to claim 7 is used to vacuum vapor deposit said two types of matrix substances A and B at the same time on a substance to be analyzed, comprising the steps of:

(a) vapor depositing said matrix substance B as a single substance and finding the relationship between the transmittance TB_B and the film thickness DB_B of a single substance film B of the matrix substance B as “

optical film thickness reference data;

”

(b) vapor depositing said matrix substance A and said matrix substance B at the same time under predetermined conditions for film formation so that a mixed film is formed, measuring the transmittance TAB_B that varies depending on the amount of application of said matrix substance B that is included in the mixed film formed under the predetermined conditions for film formation, and at the same time measuring the film thickness DAB_AB of the entirety of the mixed film by using a contact type film thickness gauge, finding the relationship between predetermined conditions for film formation and the mixture ratio of the matrix substance A and the matrix substance B in the mixed film as “

data on conditions for film formation/mixture ratio”

in reference to the “

optical film thickness reference data”

on said single substance film B, which are repeated, and storing the “

data on conditions for film formation/mixture ratio”

for the formation of a mixed film with a desired mixture ratio; and

(c) setting the conditions for film formation corresponding to a certain mixture ratio in reference to the “

data on conditions for film formation/mixture ratio”

when a mixed film with the mixture ratio is formed as a substance to be analyzed, forming a film under said conditions for film formation, and at the same time monitoring the transmittance TAB_B in the formed film in reference to the “

optical film thickness reference data”

on said single substance film B, and thus controlling the amount of application of the matrix substance B so that the amount of application has a desired value.