JPH04137446A - High-frequency inductive coupling plasma mass spectrometer - Google Patents

Abstract

PURPOSE:To improve only one side either the sensitivity or the resolution selectively so as to improve the analysis efficiency by making the bores of apertures convertible by a simple operation from the outside. CONSTITUTION:An aperture plate 21 furnishing the first to the third penetration holes 21b to 21d whose bores are different each other, a power transmitting member 22 to move the aperture plate 21 without breaking the vacuum in a center chamber, and an operating end 23 to move the aperture plate 21 are provided, and a desired bore is obtained by moving the aperture plate 21. That is, when it is decided that the analysis requires the sensitivity, the operating end 23 is moved automatically or manually to move the aperture plate 21 through the power transmitting member 22, and the penetration hole 21b is brought to the center. After that, the parameter of the analysis is adjusted and the analysis is carried out. Consequently, the analysis efficiency can be improved by improving only one side either the sensitivity or the resolution selectively.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention supplies high-frequency energy to a high-frequency induction coil to form a high-frequency magnetic field to generate high-frequency inductively coupled plasma, and uses the plasma to generate a high-frequency inductively coupled plasma. A radio frequency inductively coupled plasma mass spectrometer (rICP) analyzes the measured elements.
- MSJ), and more specifically, ICP-MS, which improves analytical characteristics by selectively improving either sensitivity or resolution. FIG. 2 is a general configuration explanatory diagram.

In this figure, argon gas is supplied from an argon gas supply source 3 to an outer chamber 1b and an outermost chamber 1c of a plasma torch 1 via a gas regulator 2, and an inner chamber 1a is supplied with a solid sample in a sample introducing device 4. is vaporized by the laser light emitted from the laser light source 5, and then carried in by argon gas, which is a carrier gas. If the sample is a liquid, the sample introducing device 4 and laser light source 5 shown in FIG. 2 are removed, and a nebulizer is installed to atomize the introduced liquid sample and supply it to the inner chamber 1a of the plasma torch 1. Also, the sample is more likely to be a liquid than a solid.

Furthermore, a high-frequency current is caused to flow through the high-frequency induction coil 6 wound around the plasma torch 1 by a high-frequency wave K11o, and a high-frequency magnetic field (not shown) is formed around the coil 6. In this state, when electrons and ions are planted in the argon gas near the high frequency magnetic field, high frequency inductively coupled plasma 7 is instantaneously generated by the action of the high frequency magnetic field.

In addition, the inside of the forechamber body 11 sandwiched between the nozzle 8 and the skimmer 9 is heated by a vacuum pump 12, for example, by ITo.
It is attracted to rr. Furthermore, center chamber 1
3 includes an aperture lens 14a and a quadruple diameter lens 1.
4b, aperture 14C1 and entrance lens 14
d, and the interior of the center chamber 13 is heated by the first oil diffusion pump 15, for example, 10-'To
rr, and the inside of the rear chamber 17 housing the quadruple diameter mass filter 16 is suctioned to, for example, 10''-'Torr by the second oil diffusion pump 18.

In this state, the sample vaporized as described above is introduced into the high-frequency inductively coupled plasma, and ionization and light emission are performed. The ions in the plasma 7 are removed by a nozzle 8 or a skimmer 9.
After passing through the ion lens systems 14a to 14d, the light is converged and introduced into the quadruple diameter mass filter 16.

Of the ions entering the 417jL-pole mass filter 16, only ions having a target mass-to-charge ratio pass through and are guided to the secondary electron multiplier 19 and detected. This detection signal is sent to the signal processing section 20 where it is calculated and processed, thereby determining the analysis value of the element to be measured in the sample.

<Problems to be Solved by the Invention> On the other hand, FIG. 3 is a sectional view taken along the line A-A in FIG. 2 and shows the main parts of the conventional example. In the inner contour line, 16a to 16d are rods of the quadruple diameter mass filter 16, 21 is an aperture plate having the same function as the aperture 14c, and 21a is a through hole drilled in the aperture plate 21.Such a main part configuration In the conventional ICP-MS, when the diameter of the through hole 21a is large, the sensitivity increases but the resolution decreases.
Conversely, it has been known that when the diameter of the through hole 21a is small, the sensitivity becomes low but the resolution becomes high. For this reason,
It is used at a compromise between sensitivity and resolution, and only unsatisfactory results can be obtained in cases where only sensitivity or resolution is required, such as when only sensitivity or resolution is desired.

The present invention has been made in view of this situation, and its object is to provide an ICP-MS in which only one of sensitivity and resolution is selectively improved to improve analytical characteristics.

Means for Solving the Problems> The present invention provides an aperture plate in which first to third through holes having different hole diameters are formed in an ICP-MS, and an aperture plate in which first to third through holes having different hole diameters are formed, and an aperture plate in which the vacuum in the center chamber is not broken. A force transmitting member for moving the aperture plate and an operating end for moving the aperture plate are provided, and the aperture plate is moved to obtain a desired hole diameter.

<Example> Hereinafter, the present invention will be described in detail using the drawings. 1st
The figure is an explanatory diagram of the main part configuration of the embodiment of the present invention, and in the figure, the third
The same symbols as in the figures are used with the same meaning, and redundant explanation will be omitted here. Further, 21b to 21d are first to third through holes drilled in the aperture plate 21, and 22 is a rotation introduction terminal, for example, and is a force transmission member that moves the aperture plate 21 without breaking the vacuum in the center chamber 13. , 23 are operating ends that are provided in a workstation (not shown), for example, and that move the aperture plate 21.

In an embodiment of the present invention having such a main configuration,
The analysis requires sensitivity (for example, when analyzing a trace amount of the analyte in the sample) or resolution (for example, when analyzing the analyte and other components in the sample). (if the elution positions of the two are close to each other).

If it is determined that the analysis requires sensitivity, the operating end 2
3 automatically or manually to move the aperture plate 21 to the right in FIG. 1 via the force transmitting member 22. That is, the through hole 21b in FIG. 1 should be centered. Then adjust the parameters of the analysis. Thereafter, the analysis is performed as described above using FIG.

If it is determined that the analysis requires sensitivity, the operating end 2
3 is operated automatically or manually to move the aperture plate 21 to the left in FIG. 1 via the force transmitting member 22. That is, the through hole 21d in FIG. 1 should be centered. Then adjust the parameters of the analysis. Thereafter, the analysis is performed as described above using FIG.

The operation of other parts of the embodiment of the present invention is the same as that of the conventional example described in detail with reference to FIG. Various modifications are possible without being limited to the first embodiment, for example, the first embodiment
The aperture plate 21 shown in the figure may be automatically moved by a motor or the like, or the through hole 21a of the aperture plate 21 shown in FIG. 3 may be continuously variable like a camera shutter.

<Effects of the Invention> As explained above in detail, the present invention is configured such that the hole diameter of the aperture can be easily changed by a simple operation from the outside. For this reason, it is possible to improve analytical characteristics by selectively improving either sensitivity or resolution
Realize CP-MS.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the configuration of the main parts of an embodiment of the present invention, FIG. 2 is a diagram illustrating the general configuration of a high-frequency induction plasma mass spectrometer, and FIG. 3 is a diagram illustrating the configuration of the main parts of a conventional example. 1... Plasma torch, 6... High frequency induction coil, 7... High frequency inductively coupled plasma,
8... Nozzle, 9... Skimmer 16
...Mass filter, 16a-16d... Quadrupole mass filter rod, 17... Rear chamber, 20... Signal processing section, 21a-21d.
...Through hole, 22...Force transmission member, 23
・・・・・・Operation end

Claims (1)

[Claims] In a high-frequency inductively coupled plasma mass spectrometer, which supplies high-frequency energy to a high-frequency induction coil to form a high-frequency magnetic field to generate high-frequency inductively coupled plasma, and uses the plasma to analyze the element to be measured in a sample, The apparatus includes an aperture plate in which different first to third through holes are bored, a force transmission member that moves the aperture plate without breaking the vacuum in the center chamber, and an operating end that moves the aperture plate. ,
A high frequency inductively coupled plasma mass spectrometer, characterized in that the aperture plate is moved to obtain a desired hole diameter.