Analytical system and method utilizing the dependence of signal intensity on matrix component concentration

• US 7,829,846 B2
• Filed: 02/26/2008
• Issued: 11/09/2010
• Est. Priority Date: 09/06/2007
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sugiyama, Masuyuki, Hashimoto, Yuichiro, Takada, Yasuaki, Hasegawa, Hideki
• Primary Examiner(s): Vanore; David A
• Application Number:
  US12/037,148
• Publication Number:
  US 20090065688A1
• Time in Patent Office: 987 Days
• Field of Search: None
• US Class Current: 250/288
• CPC Class Codes: H01J 49/0036 Step by step routines describing the handling of the data generated during a measurement

Abstract

The present invention achieves accurate quantitative determination without reducing measurement throughput and also without having to add a multi-component reference standard. An analytical instrument of the present invention for determining the concentration of a target compound contained in a target sample includes: a means for ionizing a mixture having a specific compound added to the target sample; a means for performing mass analysis on resulting ions; and a database that stores dependence of signal intensity on the concentration of a specific matrix component for each of the target compound and the addition compound, wherein the database is used to calibrate the concentration of the target compound from a signal derived from the target compound and a signal derived from the addition compound, each signal obtained by the mass analysis means. The present invention achieves a multi-component analyzer using low-cost, high-throughput mass analysis, as compared to conventional technique.

Claims

1. An analytical instrument, comprising:

an ionization means for ionizing a mixture of a target sample and a specific compound added thereto;

a means for performing mass analysis on resulting ions; and

a data processor that determines the concentration of a target compound contained in the target sample,

wherein the data processor includes a database that stores dependence of signal intensity on the concentration of a specific matrix component for each of the target compound and the addition compound, and the data processor calculates, by using the database, the concentration of the target compound from a signal derived from the target compound and a signal derived from the addition compound, each signal obtained by the mass analysis means.

2. The mass spectrometer according to claim 1, wherein the database stores the dependence of signal intensity according to each ionization method.

3. The analytical instrument according to claim 1, further comprising:

a means for introducing the target sample;

a means for introducing the addition compound; and

a separating means for separating the introduced target sample,

wherein the mixture is introduced into the ionization means.

4. The analytical instrument according to claim 3, wherein the separating means is provided between the means for introducing the target sample and the means for introducing the addition compound.

5. The analytical instrument according to claim 3, wherein the means for introducing the addition compound is provided between the means for introducing the target sample and the separating means.

6. The analytical instrument according to claim 1, wherein the addition compound is a plurality of compounds of different dependences of the signal intensity on the concentration of the matrix component, stored in the database.

7. The analytical instrument according to claim 1, wherein the matrix component is blood or a component extracted from the blood.

8. The analytical instrument according to claim 1, wherein the matrix component is salt.

9. The analytical instrument according to claim 1, wherein the target sample is a liquid.

10. The analytical instrument according to claim 1, wherein the target sample is a gas.

11. The analytical instrument according to claim 1, wherein a mixture having a specific ionization-assisting chemical material added to the target sample is spotted on a sample plate, and the spotted sample is ionized by the ionization means.

12. An analysis method for determining the concentration of a target compound contained in a target sample, comprising the steps of:

ionizing, by an ionization unit, a mixture of a target sample and a specific compound added thereto;

making measurements on resulting ions, by a mass analyzer; and

calculating, by a data processor using a database, the concentration of the target compound from a signal derived from the target compound and a signal derived form the addition compound, which signals are measured by the mass analyzer, the database storing dependence of signal intensity on the concentration of a specific matrix component for each of the target compound and the addition compound.

13. The analysis method according to claim 12, wherein a plurality of compounds of known concentrations and of different matrix effects stored in the database are added to the target sample.

14. The analysis method according to claim 12, wherein the mass analyzer performs tandem mass spectrometry so as to obtain an m/z value of the resulting ions from the mixture, an m/z value of ions produced by dissociation of the resulting ions, and information on the ion intensities of the resulting ions and the produced ions, and the data processor performs data processing using the database and the obtained m/z values and the information from the mass analyzer.

15. A calibration method for sensitivity changes in a mass spectrometer, comprising the steps of:

introducing a compound of known concentration into an ionization unit;

measuring ion intensity derived from the ionized compound, by a mass analyzer; and

performing, by a data processor using a database, a comparison with the sensitivity of the compound observed when the concentration of the matrix component is 0, the database storing dependence of signal intensity on the concentration of a matrix component for the compound.

16. The calibration method according to claim 15, wherein the data processor performs calibration of the database, by using the result of measurement by the mass analyzer, on the basis of the result of the comparison.

17. The calibration method according to claim 15, wherein the compound of known concentration is a plurality of compounds of different m/z values.