JPH07263182A - Ignition mechanism of high frequency inductively coupled plasma device - Google Patents

Abstract

PURPOSE:To provide ignition mechanism capable of easily conducting plasma ignition by arranging a valve for branching gas in the latter step of a gas flow controller. CONSTITUTION:Usually, a valve 9 is closed. When plasma is ignited, the valve 9 is opened, the gas flow amount of a gas flow controller 3 is minimized, gas flowing out through the gas flow controller 3 is branched to the outside of a path through the valve 9, and gas flowing in a nebulizer 4 is made almost zero. In this state, when ignition is conducted with an igniter, plasma ignition is easily conducted without carrying in of moisture into a torch tube. By using the valve 9 as a switching valve, the branched gas can be utilised for other applications.

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 diagram showing an example of an ignition mechanism of a conventional ICP device. Gas from the gas cylinder 1 is introduced into the torch pipe 7 through the pressure reducing valve 2 by the gas flow controller 3 divided into three systems. One of the three systems is used as a plasma gas, one is an auxiliary gas, and the other is used for atomizing and transporting the sample liquid 5, so that it is flown into the nebulizer 4. 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, in which the mist having a large particle size contacts the inner cylinder and is liquefied, and the mist particle size is made uniform and supplied to the torch pipe 7 together with the carrier gas. It A load coil 8 is provided around the torch tube 7, and ignition is performed by an igniter 9 and excitation is performed by the load coil 8 to form plasma 10.

[0003]

By the way, 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 substantially zero. The gas flowing to the nebulizer 4 uses a mass flow controller type as the gas flow controller 3 in order to ensure the stability and reproducibility of atomization. This controller is difficult to control when the flow rate is near 0 There is a problem that gas flows in. When the gas flows in, especially when there is water in the spray chamber 6, this water (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 solve the above-mentioned problems, and an object thereof 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 device of the present invention is provided with an ignition device and a load coil by atomizing a sample liquid with a nebulizer by gas supplied through a gas flow controller. In a high frequency inductively coupled plasma device that is introduced into a torch tube to generate plasma, a bypass flow path is provided in the flow path from the gas flow controller to the nebulizer, and a valve is arranged in the flow path. It is characterized in that the gas for the nebulizer is made to flow to the bypass flow path by opening.

[0006]

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

[0007]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 1 shows the gas flow introduced into the nebulizer among the gas flows of the three systems in FIG. 2, and the same numbers as in FIG. 2 indicate the same contents. In FIG. 1, FIG.
Is that a valve 9 for branching the gas is arranged in the subsequent stage of the gas flow controller 3. That is, the valve 9 is normally used in the closed state, and the operation at that time is the same as in the case of FIG. When the plasma is ignited, the valve 9 is opened, and when the gas flow rate of the gas flow controller 3 is set to the minimum state, the gas still flowing out through the gas flow controller 3 is allowed to escape to the outside of the flow path through the valve 9. To In this state, if ignition is performed by the igniter 9 as shown in the figure, since water is not carried into the torch tube 7, plasma ignition can be easily performed. When the plasma ignites, the valve 9 is closed.

In the above embodiment, a pipe having a small flow resistance may be connected further downstream of the valve 9 and the valve 9 may be used as a switching valve to use the nebulizer gas for other purposes. . Further, the valve 9 may of course be either manual or automatic.

[0009]

As described above, according to the present invention, the gas flowing into the nebulizer can be reduced to almost zero.
Ignition of plasma becomes easier, and a valve that branches when plasma is ignited can be used as a switching valve.
It is possible to easily use the nebulizer gas for other purposes.

[Brief description of drawings]

FIG. 1 is a diagram showing an 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]

1 ... Gas cylinder, 2 ... Pressure reducing valve, 3 ... Gas flow controller, 4 ... Nebulizer, 5 ... Sample liquid, 9 ... Valve.

Claims (1)

[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 igniter and a load coil to generate plasma. In the device, a bypass flow path is provided in the flow path from the gas flow controller to the nebulizer, a valve is arranged in the flow path, and at the time of plasma ignition, the valve is opened to allow the gas to the nebulizer to flow to the bypass flow path. Ignition mechanism of high-frequency inductively coupled plasma device characterized by: