JP3037058B2 - Ignition mechanism of high frequency inductively coupled plasma device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition mechanism for a high frequency inductively coupled plasma (ICP) device.

[0002]

2. Description of the Related Art FIG. 2 is a view showing an example of an ignition mechanism of a conventional ICP device. The gas from the gas cylinder 1 is introduced into the torch tube 7 through the pressure reducing valve 2 and divided into three systems by the gas flow controller 3. One of the three systems is supplied to the nebulizer 4 for use in plasma gas, one for auxiliary gas, and the other for atomization and transport of the sample liquid 5. The gas introduced into the nebulizer 4 is introduced into the central barrel of the torch tube 7 through the spray chamber 6 together with the mist of the sample liquid 5. The spray chamber 6 is provided with a cylindrical inner cylinder 6a. Here, the mist having a large particle diameter comes into contact with the inner cylinder and liquefies, and the mist having a uniform particle diameter is supplied to the torch tube 7 together with the carrier gas. You. A load coil 8 is provided around the torch tube 7, and is ignited by an igniter 9 and excited by the load coil 8 to form a plasma 10.

[0003]

However, the plasma 1
When 0 is ignited and formed, it is necessary to apply a high voltage from the igniter 9 to the torch tube 7 with the gas flowing through the nebulizer 4 being almost zero. The gas flowing into the nebulizer 4 uses a mass flow controller type as the gas flow controller 3 in order to secure the stability and reproducibility of the atomization. There is a problem that gas flows in. When the gas flows, especially when there is moisture in the spray chamber 6, this moisture (water vapor) is also carried into the torch, which is a disadvantageous condition for plasma ignition, and plasma ignition is not easy.

An object of the present invention is to provide an ignition mechanism of a high-frequency inductively coupled plasma device which can easily perform plasma ignition of an ICP device.

[0005]

The ignition mechanism of the high-frequency inductively coupled plasma apparatus according to the present invention atomizes a sample liquid by a nebulizer with a gas supplied through a gas flow controller, and is provided with an ignition apparatus and a load coil. In a high-frequency inductively coupled plasma apparatus which is introduced into a torch tube and turned into plasma, a bypass flow path is provided in a flow path from the gas flow controller to the nebulizer, and a valve is disposed in the flow path, and the valve is provided at the time of plasma ignition And the gas to the nebulizer is caused to flow to the bypass flow path.

[0006]

According to the present invention, the gas flowing into the nebulizer through the gas flow controller is branched through the valve at the time of plasma ignition, so that the gas flowing into the nebulizer can be reduced to almost zero, and the plasma ignition becomes extremely easy. ,
The branched gas can also be used for other purposes.

[0007]

FIG. 1 is a diagram showing one embodiment of the present invention. FIG. 1 shows the gas flow introduced into the nebulizer among the three gas flows in FIG. 2, and the same numbers as those in FIG. 2 indicate the same contents. In FIG. 1, FIG.
The difference from the first embodiment is that a valve 9 for branching the gas is provided at a stage subsequent to the gas flow controller 3. That is, the valve 9 is normally used in a closed state, and the operation at that time is the same as that in FIG. When the plasma is ignited, the valve 9 is opened, and when the gas flow rate of the gas flow controller 3 is minimized, the gas which still flows through the gas flow controller 3 is allowed to escape to the outside of the flow path via the valve 9. To In this state, if ignition is performed by an igniter 9 as shown in the figure, since no water is carried into the torch tube 7, plasma ignition can be easily performed. When the plasma ignites, valve 9 is closed.

In the above-described embodiment, a pipe having a small flow resistance may be connected downstream of the valve 9 so that the valve 9 may be used as a switching valve, and may be used as a valve for utilizing nebulizer gas for other purposes. . Also, the valve 9 may be manually or automatically.

[0009]

As described above, according to the present invention, the gas flowing into the nebulizer can be reduced to almost zero.
Plasma ignition is facilitated, and a valve that branches at the time of plasma ignition can be used as a switching valve.
The nebulizer gas can be easily used for other purposes.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing an example of an ignition mechanism of a conventional ICP device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... gas cylinder, 2 ... pressure reducing valve, 3 ... gas flow controller, 4 ... nebulizer, 5 ... sample liquid, 9 ... valve.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 27/62-27/70 H05H 1/24-1/52 H01J 49/00-49/48 G01N 21/73

Claims (1)

(57) [Claims] 1. A high-frequency inductively coupled plasma in which a sample liquid is atomized by a nebulizer by a gas supplied through a gas flow controller, and introduced into a torch tube provided with an ignition device and a load coil to generate plasma. In the apparatus, a bypass flow path is provided in a flow path from the gas flow controller to the nebulizer, and a valve is disposed in the flow path. At the time of plasma ignition, the valve is opened to flow gas to the nebulizer through the bypass flow path. An ignition mechanism for a high-frequency inductively coupled plasma device.