JPH04124746U - High frequency inductively coupled plasma mass spectrometer - Google Patents

Description

[Detailed explanation 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 excite a sample to generate ions. Regarding high frequency inductively coupled plasma mass spectrometers that analyze analyte elements in the sample by guiding them through an interface to a mass spectrometer for detection, in particular high frequency inductively coupled plasma mass spectrometers that use low cost diffusion pumps and are desktop capable. Concerning coupled plasma mass spectrometry.

<Conventional technology>
FIG. 3 is an explanatory diagram of a general configuration of an analyzer using high frequency inductively coupled plasma. 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 introduction device 4 and laser light source 5 shown in FIG. 3 are removed, and a nebulizer is installed to atomize the liquid sample to be introduced 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.

On the other hand, a high frequency current is passed through a high frequency induction coil 6 wound around the plasma torch 1 by a high frequency power supply 10, and a high frequency magnetic field (not shown) is formed around the coil 6. When electrons or ions are planted in the argon gas in the vicinity of the high frequency magnetic field in this state, high frequency inductively coupled plasma 7 is instantaneously generated by the action of the high frequency magnetic field.

Further, the inside of the forechamber main body 11 sandwiched between the nozzle 8 and the skimmer 9 is heated to a pressure of, for example, 1 Torr by a vacuum pump 12. is attracted to. Furthermore, an ion lens 14 is installed in the center chamber 13.
a and 14b, and the interior of the center chamber 13 is heated to a temperature of, for example, 10 ⁻⁴ Torr. The interior of the rear chamber 17, which accommodates a mass filter (for example, a quadrupole mass filter) 16, is heated to a pressure of, for example, 10 ⁻⁵ Torr. is attracted to.

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 pass through the nozzle 8, the skimmer 9, and the extraction electrode ⁹ , and then are focused between the ion lenses 14a and 14b (or doublet quadrupole lens), and then pass through the mass filter 16. The electrons are guided to the secondary electron multiplier tube 19 and detected. By sending this detection signal to the signal processing section 20 and calculating and processing it, the analysis value of the element to be measured in the sample is determined.

FIG. 3 is a sectional view taken along the line ^AA in FIG. 2, and in the figure, the same symbols as in FIG. 2 are used with the same meanings, and redundant explanation will be omitted here. Further, 21 indicates the second forechamber 11 and the center chamber 13.
22 is the connection part connecting the first oil diffusion pump 1
5 is connected to the center chamber 13, for example, by a snap-lock type holder.

In this figure, it is an absolute requirement that the first oil diffusion pump 15 be installed vertically. Therefore, the height l ₂ of the center chamber 13 is added to the height l ₁ of the first oil diffusion pump 15 . Therefore, the height of the ICP-MS becomes large, making it difficult to miniaturize the ICP-MS, and as a result, making it difficult to convert the ICP-MS into a so-called desktop.

<Problem that the idea aims to solve>
The present invention has been devised in view of the above circumstances, and its object is to provide a high-frequency inductively coupled plasma mass spectrometer that uses a low-cost diffusion pump and is capable of being desktop-operated.

<Means to solve the problem>
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 excite a sample to generate ions. In a high-frequency inductively coupled plasma mass spectrometer that analyzes the analyte in the sample by guiding it to the mass spectrometer via an interface and detecting it, a center chamber is connected to a forechamber sandwiched between a nozzle and a skimmer. , a first oil diffusion pump that depressurizes the inside of the center chamber, a rear chamber that accommodates a detector of the mass spectrometer, and a second oil diffusion pump that depressurizes the inside of the rear chamber; is formed into an inverted L shape, and the first oil diffusion pump is accommodated in the space.

<Example>
Hereinafter, the present invention will be explained in detail using figures. FIG. 1 is an explanatory diagram of the main structure of an embodiment of the present invention. In the figure, the same symbols as in FIG. 3 are used with the same meanings, and redundant explanation will be omitted here. Also, 2
3 is an inverted L-shaped center chamber manufactured by cutting an aluminum block, and 22 ^- is the first chamber.
For example, a snap-lock type holder connects the oil diffusion pump 15 to the center chamber 21, and 24 is a storage space for storing a power source, a vacuum converter, and the like. In the embodiment of the present invention having such a configuration of main parts, the first oil diffusion pump 15 is connected to the space of the inverted L-shaped center chamber 21 (more specifically, the inverted L-shaped center chamber 21 and the storage space 23 It is located in a space formed by For this reason, the first oil diffusion pump 15 and the center chamber 21 are both smaller in vertical dimension and depth than in the conventional example shown in Fig. 3, and as a result, the ICP-MS as a whole becomes smaller. This also makes it possible to create a so-called desktop.

It should be noted that the present invention is not limited to the above-mentioned embodiment and can be modified in various ways. For example, a part of the first oil diffusion pump 15 may be partially protruded from the lower line of the storage space 23. It may be a configuration. Further, since the operation of the ICP-MS itself is exactly the same as that of the conventional example, repeated explanation will be omitted here.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the main part configuration of the embodiment of the present invention, Figure 2
The figure is an explanatory diagram of the general configuration of a high frequency inductively coupled plasma mass spectrometer, and FIG. 3 is an explanatory diagram of the main part configuration of a conventional example. 1... Plasma torch, 2... Flow rate control section, 3
...Argon gas supply source, 4...Sample cell, 6...
...High frequency induction coil, 7...High frequency inductively coupled plasma, 8...Nozzle, 9...Skimmer, 16...
Mass filter, 17... Rear chamber, 20...
...Signal processing section, 21... Connection section, 22, 22'...
...Holder, 23...Center chamber, 24...
...storage space.

Correction Heisei 4.6.11
The name of the invention is amended as follows. Name of invention: High frequency inductively coupled plasma mass spectrometer

Claims (1)

[Scope of utility model registration request] High frequency energy is supplied to a high frequency induction coil to form a high frequency magnetic field to generate a high frequency inductively coupled plasma, the plasma is used to excite the sample to generate ions, and the ions are transferred through an interface consisting of a nozzle and a skimmer. In a high-frequency induction plasma mass spectrometer that analyzes the analyte element in the sample by guiding it to a mass spectrometer and detecting it, the center chamber includes a center chamber connected to the fore chamber sandwiched between the nozzle and the skimmer; A first oil diffusion pump that depressurizes the inside of the bar, a rear chamber that houses the detector of the mass spectrometer, and a second oil diffusion pump that depressurizes the inside of the rear chamber, and the center chamber is turned into an inverted L. 1. A high-frequency inductively coupled plasma mass spectrometer, characterized in that the first oil diffusion pump is housed in a space formed in a square shape.