JPH06102249A - High frequency induction coupling plasma mass spectroscope - Google Patents

Abstract

PURPOSE:To obtain a high frequency induction coupling plasma mass spectroscope which enables the applying of a sheath gas with a construction easier to handle, and small and simple having a shorter pass. CONSTITUTION:A high frequency induction coupling plasma mass spectroscope is so arranged to convey a sample atomized with a nebulizer 5 to a plasma torch through a spray chamber 23. An outlet port of a spray chamber 23 which is connected to the plasma torch is arranged as double pipe and the sample atomized is applied to an inner tube of the double pipe while a sheath gas is applied to an outer tube thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency inductively coupled plasma mass spectrometer, and more particularly to improvement of a spray chamber in a sample introduction system.

[0002]

2. Description of the Related Art A high-frequency inductively coupled plasma mass spectrometer uses a high-frequency inductively coupled plasma as an ionization source and uses a quadrupole mass filter as a mass spectrometric unit to detect many elements present in a sample with high sensitivity all at once. It is a device that can be measured, and is being used for various analyzes as a device capable of analyzing a trace amount of ppt (part per trillion) level.

That is, a high frequency inductively coupled plasma mass spectrometer uses a high frequency inductively coupled plasma to excite a sample to generate ions, and guides the generated ions to a mass spectrometer through an interface composed of a nozzle and a skimmer. By electrically detecting and accurately measuring the amount of ions, the element to be measured in the sample is analyzed with high accuracy.

FIG. 2 is an explanatory view of a conventional configuration example of such a high frequency inductively coupled plasma mass spectrometer. In the figure, argon gas Ar is supplied from an argon gas supply source 3 to the outer chamber 1b and the outermost chamber 1c of the plasma torch 1 via a gas regulator 2, and the sample in the sample tank 4 is nebulized in the inner chamber 1a. After being atomized in 5, it is carried in by argon gas Ar. A high frequency induction coil 6 is wound around the plasma torch 1, and a high frequency current is applied to the high frequency induction coil 6 from a high frequency power supply 10 to form a high frequency magnetic field around the coil 6. On the other hand, the inside of the fore chamber body 11 sandwiched between the nozzle 8 and the skimmer 9 is, for example, 1 Torr.
Have been sucked into. Further, the center chamber 13 is provided with ion lenses 14a and 14b, and
The inside of the center chamber 13 has a first oil diffusion pump 1
5, for example, to 10 ⁻⁴ Torr., And the inside of the rear chamber 17 housing the mass filter (eg, quadrupole mass filter) 16 is sucked to, for example, 10 ⁻⁵ Torr. By the second oil diffusion pump 18. Has been done.

In this state, when electrons or ions are implanted in the argon gas in the vicinity of the high frequency magnetic field, the high frequency magnetic field 7 instantly generates high frequency induction plasma 7. Ions in the plasma 7 pass through the nozzle 8 and the skimmer 9 and then pass through between the ion lenses 14a and 14b (or doublet quadrupole lens) to be converged, and then pass through the mass filter 16 and the secondary electron multiplier tube. By being guided to 19 and detected, the detected signal is sent to the signal processing section 20 and subjected to arithmetic processing, whereby the measured elemental analysis value in the sample is obtained.

By the way, in the analysis of the sample, it has been proposed to add a new sheath gas after the nebulizer 5 and mix them. FIG. 3 is a configuration diagram of a conventional main part in the case of mixing the gases in this way, the same parts as those in FIG. 2 are denoted by the same reference numerals, and the re-explanation thereof will be omitted. A sheath gas instrument 21 and a spray chamber 22 are connected between the inner chamber 1 a of the plasma torch 1 and the nebulizer 5. The device 21 is formed in a double pipe structure and is provided with three connection ports 21a, 21b, 21c. The connection port 21a communicates with the inner pipe and is connected to the spray chamber 2
2 is connected, the connection port 21b is connected to the outer tube and the inner chamber 1a of the plasma torch 1 is connected, and the connection port 21c is connected to the outer tube and the sheath gas is supplied. The spray chamber 22 is also provided with three connection ports 22a, 22b, 22c, and the nebulizer 5 is also provided with three connection ports 5a, 5b,
5c is provided. The connection port 22a of the spray chamber 22 is connected to the connection port 5c of the nebulizer 5, the connection port 22b is connected to the connection port 21b of the instrument 21, and the connection port 22c is supplied with argon gas. The sample is supplied to the connection port 5a of the nebulizer 5, and the connection port 5b
Argon gas is supplied to.

As a result, the sample atomized by the nebulizer 5 is carried into the inner chamber 1a of the plasma torch 1 via the sheath gas and the argon gas.

[0008]

However, according to such a conventional configuration, the inner chamber 1a of the plasma torch 1 is formed.
The two components of the sheath gas device 21 and the spray chamber 22 must be connected between the nebulizer 5 and the nebulizer 5, resulting in a problem that the path becomes long, downsizing is difficult, the handling is inconvenient, and the mounting is complicated. is there.

The present invention has been made in view of the above conventional problems, and its object is a high-frequency inductively coupled plasma mass with a short path, a small size, a simple structure and easy handling. It is to provide an analyzer.

[0010]

A high frequency inductively coupled plasma mass spectrometer according to the present invention is a high frequency inductively coupled plasma mass spectrometer configured to convey a sample atomized by a nebulizer to a plasma torch through a spray chamber. In the analyzer, the output port of the spray chamber connected to the plasma torch is configured as a double tube, the atomized sample is added to the inner tube of the double tube, and the sheath gas is added to the outer tube. It is a feature.

[0011]

The sample atomized by the nebulizer is mixed with the sheath gas at the output port of the spray chamber and conveyed to the plasma torch.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of a main part of an embodiment of the present invention, in which parts common to those in FIG. 3 are designated by common reference numerals and re-explanation thereof will be omitted. In the figure, 23 is a spray chamber, and three connection ports 23a, 23b,
23c is provided. The connection port 5a of the nebulizer 5 is connected to the connection port 23a, the inner chamber 1a of the plasma torch 1 is connected to the connection port 23b, and the sheath gas is supplied to the connection port 23c. Here, the connection ports 23b and 23c are formed in a double tubular shape so as to form the output port of the spray chamber 23. That is, the atomized sample is added from the spray chamber 23 to the inner tube of the double tube, and the sheath gas is added to the outer tube from the connection port 23c.

In such a structure, the aerosol having large particles contained in the sample atomized by the nebulizer 5 collides with the wall 23d of the spray chamber 23 and is drained.
The aerosol with small particles, which is collected in 3e, advances toward the plasma torch 1 and is mixed with the sheath gas at the output port of the spray chamber 23 formed in the double tube shape.

As a result, similarly to the configuration of FIG. 3, the sample atomized by the nebulizer 5 is carried into the inner chamber 1a of the plasma torch 1 via the sheath gas and the argon gas.

[0015]

According to the present invention described above, the following effects can be obtained. That is, since the function of the sheath gas device, which has been conventionally attached and detached as an independent device between the spray chamber and the inner chamber 1a of the plasma torch 1, is incorporated into the spray chamber and integrated, the path is shortened,
Since it can be downsized and can be handled like a conventional spray chamber, it is easy to handle.

Further, since the size can be reduced, it is expected that the cooling by the Peltier element can be easily dealt with.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a high frequency inductively coupled plasma mass spectrometer.

FIG. 3 is a configuration diagram around a conventional spray chamber.

[Explanation of symbols]

 1 Plasma torch 5 Nebulizer 23 Spray chamber

Claims (1)

[Claims] 1. A high frequency inductively coupled plasma mass spectrometer configured to convey a nebulized atomized sample to a plasma torch through a spray chamber, wherein an output port of the spray chamber connected to the plasma torch is A high frequency inductively coupled plasma mass spectrometer, which is configured as a double tube, in which an atomized sample is added to an inner tube of the double tube and a sheath gas is added to an outer tube.