JP2568132Y2 - Exhaust device in high frequency inductively coupled plasma mass spectrometer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for insulating an exhaust device in a mass spectrometer using a high frequency inductively coupled plasma (ICP) ion source.

[0002]

2. Description of the Related Art FIG. 1 shows a mass spectrometer using an ICP ion source. In the figure, reference numeral 18 denotes an ICP ion source, a plasma torch 13 made of an electric insulator such as quartz wound with a high-frequency induction coil 12, and a nebulizer 1 for spraying a sample liquid.
6 is comprised. 19 is an aperture plate 2 or 3
An acceleration voltage of 5 KV to 10 KV is applied to each aperture plate by the acceleration power supply 7. Reference numeral 20 denotes a mass spectrometer having a mass spectrometry system 14 therein, and is insulated from the interface 19 by an insulating member 17. Reference numeral 4 denotes a rotary pump for exhausting the intermediate exhaust chamber 15 formed between the aperture plates, and reference numeral 5 denotes a motor for driving the pump 4. Reference numeral 8 denotes a high-voltage power supply provided to apply the same voltage as the acceleration power supply 7 or a voltage lower than the acceleration voltage to the motor 5 and the rotary pump 4. An insulating transformer 6 is provided between the motor driving power supply 11 and the motor 5.

In such a configuration, the plasma torch 1
Argon gas is supplied from a gas supply source (not shown) into the inside 3, and a sample liquid is sprayed from a nebulizer 16. In this state, a high-frequency inductively coupled plasma 1 is generated by supplying a high-frequency power from a high-frequency power source (not shown) to the coil 12 to form a high-frequency magnetic field. 3 and is introduced into the mass spectrometer 20 while being accelerated.
At this time, the plasma gas and other sample ions are exhausted by the rotary pump 4 from the intermediate exhaust chamber.

[0004]

However, if the rotary pump and the motor are set at the ground potential, discharge is likely to occur through the exhaust pipe between the aperture plates 2 and 3 and the rotary pump. Therefore, in the above conventional example, a high voltage is also applied to the rotary pump and the motor to reduce the potential difference between the aperture plates 2 and 3. In order to keep the motor at a high potential, an insulating transformer must be interposed between the motor and the power supply 11 placed at the ground potential. For this reason, there is a problem that the entire exhaust device becomes large and costs increase.

The present invention has been made in view of the above problems, and has as its object to provide an exhaust device for a high-frequency inductively coupled plasma mass spectrometer capable of preventing discharge without using an insulating transformer or the like. And

[0006]

Means for Solving the Problems In order to achieve the above object, the present invention provides a high frequency inductively coupled plasma ion source for ionizing a sample with a high frequency inductively coupled plasma, and introducing ions generated by the ion source. A mass spectrometry system for mass spectrometry of the sample, an intermediate exhaust chamber provided between the ion source and the mass spectrometer, and an intermediate exhaust chamber, the ion source, and the intermediate exhaust chamber and the intermediate exhaust chamber and the mass spectrometer. , An acceleration power supply for applying an acceleration voltage to at least one of the aperture plates to accelerate ions passing therethrough, exhaust means for exhausting the intermediate exhaust chamber, and driving for driving the exhaust means Means, the exhaust means and the driving means are insulated and connected (<
In addition to the underline = medium fine line>), a discharge preventing voltage is applied to the exhaust means.

[0007]

According to the present invention, the pump and the motor that drives the pump are insulated by an insulating member.

[0008]

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(<Underline = medium thin line>) In FIG. 2, the same components as those in the conventional example of FIG. 1 are denoted by the same reference numerals.
In FIG. 2, reference numeral 10 denotes an insulating coupling for insulatingly connecting the rotary pump 4 and the motor 5. Reference numeral 9 denotes an insulating member provided to insulate the pump 4 from the motor 5 (<underline = medium fine line>).
Is applied.

In such a configuration, the pump is driven by a motor insulated by an insulating coupling to exhaust the intermediate exhaust chamber. Furthermore, by insulating the connection between the pump and the motor via an insulating member and applying a voltage to the pump, discharge can be prevented without providing an insulating transformer in the power supply for driving the motor.

In the above embodiment, the same acceleration voltage is applied to the two apertures. However, as long as the ions can be accelerated, the present invention is not limited to this.
Or different voltages may be applied independently of each other. Also, the high-voltage power supply provided in the pump may be omitted and shared with the acceleration power supply, or when provided separately, the voltage may be changed in conjunction with the acceleration power supply.

[0012]

[Effects of the Invention] As described in detail above, the present invention connects the pump and the motor in an insulative manner, and maintains the pump at a high potential without providing an insulating transformer in the motor (<underline = medium thin line>). Can be prevented. Thus, the size of the exhaust device can be reduced, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a conventional example.

FIG. 2 is a view for explaining an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 7: Acceleration power supply 8: High voltage power supply 9: Insulation member 10: Insulation coupling

Claims (1)

(57) [Scope of request for utility model registration] 1. A high-frequency inductively coupled plasma ion source for ionizing a sample with a high-frequency inductively coupled plasma, a mass spectrometry system for introducing ions generated by the ion source to perform mass spectrometry of the sample, An intermediate exhaust chamber provided between the mass spectrometry systems, two aperture plates partitioning the intermediate exhaust chamber, the ion source, and the intermediate exhaust chamber and the mass spectrometry system, and at least one of the aperture plates; An accelerating power supply that applies an accelerating voltage to accelerate ions passing therethrough, and an exhaust unit that exhausts the intermediate exhaust chamber,
In a device provided with a driving means for driving the exhaust means, the exhaust means and the driving means are insulated from each other, and a voltage for preventing discharge is applied to the exhaust means. Exhaust device in high frequency inductively coupled plasma mass spectrometer.