JPH0212748A - Plasma mass analysis device of high-frequency inductive coupling type - Google Patents

Abstract

PURPOSE:To prevent to deposit a component to be measured at a nozzle and to block the nozzle even though the component to be measured in a gas phase sample is highly dense by feeding the sample to a sample collecting valve to fill the inside of a measuring pipe of a constant inside volume, and then, leading the sample collecting valve to the inner chamber of a plasma torch with a switching carrier gas. CONSTITUTION:After the inside of a measuring pipe of a constant inner volume is filled by feeding a sample to a sample collecting valve 17, the sample collecting valve 17 is led to the inside chamber 3 of a plasma torch with a switching carrier gas. In this case, the sample collecting valve 17 may be a four-side switching valve including a back pressure regulator formed as a three- side switching valve, or two four-way switching valves holding a single measuring pipe. By such a constitution, a component to be measured is never deposited at a nozzle, or it never blocks the nozzle, even though the component to be measured is highly dense.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention involves exciting a sample using high-frequency inductively coupled plasma and guiding the generated ions to a mass spectrometer detector through an interface consisting of a nozzle and a skimmer. The present invention relates to a high frequency inductively coupled plasma mass spectrometer that analyzes an element to be measured in the sample by detecting it.

<Prior Art> FIG. 2 is an explanatory diagram of the main part configuration of a conventional example showing the main parts of a conventional example of such a high frequency inductively coupled plasma mass spectrometer.
In the figure, 1 is the main body of the high-frequency inductively coupled plasma mass spectrometer;
2 is the plasma torch, 3 is the inner chamber of plasma torch 2, 4
is an outer chamber of the plasma torch 2, 5 is the outermost chamber of the plasma torch 2, 6 is a high frequency induction coil wound around the outside of the plasma torch 2, 7 is a high frequency induction plasma, 8 is a nozzle, 9
1 is a skimmer; 10 is a center chamber containing, for example, an ion lens; 11 is a mass spectrometry section; 12 is a secondary electron multiplier tube; 13 is an arithmetic processing section consisting of, for example, a microcomputer; and 14 is a sample gas inlet. In the conventional example having such a configuration, the sample was introduced directly into the inner chamber 3 of the plasma torch from the sample gas inlet. In addition, the sample directly introduced into the inner chamber 3 of the plasma torch in this way is excited by high-wave inductively coupled plasma, and the generated ions are guided to the mass spectrometer 11 through an interface consisting of a nozzle 8 and a skimmer 9, and are electrically The element to be measured in the sample can be analyzed with high accuracy by detecting the ion and precisely measuring the amount of the ion.

<Problems to be Solved by the Invention> However, in the above-mentioned conventional example, if the component to be measured (for example, AI, Zγ, 81, etc.) in the sample in the gas phase is at a high concentration, the component to be measured may be removed from the nozzle. There was a drawback that there was a risk that the nozzle would be clogged due to precipitation. On the other hand, in the case of the sample or liquid, a so-called flow injection method is used to transport a certain amount of the sample using a carrier solution as a moving layer, thereby effectively preventing the nozzle from clogging as described above.

The present invention has been made in view of this situation, and its purpose is to prevent the nozzle from being blocked due to precipitation of the component to be measured at the nozzle, even if the component to be measured in the gas phase sample has a high concentration. An object of the present invention is to provide a high frequency inductively coupled plasma mass spectrometer that does not cause blockage.

A feature of the present invention that solves the above-mentioned problems is that in a high-frequency inductively coupled plasma mass spectrometer, a sample is sent to a sampling valve to fill a metering tube with a constant internal volume. The sampling valve is then switched and guided with a carrier gas into the interior chamber of the plasma torch.

<Example> Hereinafter, the present invention will be described in detail using the drawings. 1st
The figure is an explanatory diagram of the main part configuration of the embodiment of the present invention, and in the figure, the second
The same symbols as those in the figures are used with the same meaning, and redundant explanation will be omitted here. Further, 15 is a sample outlet, 16 is a carrier gas inlet, and 17 is the first to sixth connection ports 17a to 1.
7f and a measuring tube 17g with a constant internal volume. Third. and the fifth connection ports 17a, 17c, and 17e are connected to the second connection ports 17a, 17c, and 17e, respectively. The first state is connected to the fourth and sixth connection ports 17b, 17d, and 17f, respectively. Third. The fifth connection port is connected to the sixth connection port. Second. and a second state connected to the fourth connection port, respectively. In addition, this sample collection valve has a configuration in which a first state in which the sample is introduced into the measuring tube and is guided directly to the plasma torch by bypassing the carrier, and a second state in which the carrier flows through the measuring tube are repeated during mating. Various modifications are possible; for example, it may be one three-way switching valve, one four-way switching valve with a back pressure regulator, or two four-way switching valves sandwiching a metering tube. shall be. Further, a flow rate control valve for a sample is provided between the sample introduction port 14 and the sample collection valve 17g shown in FIG. 1, and a flow rate control valve for the carrier is provided between the carrier introduction port 15 and the sample collection valve 17g shown in FIG. may be provided.

Furthermore, in the embodiment of the present invention consisting of the above-mentioned main part configuration, a flow control valve may be arranged between the sample collection valve 17g and the plasma torch 2 instead of these flow control valves. , the sample sampling valve 17 is off and its internal flow path is in a solid line connection state. In this state, the sample introduced from the sample introduction port 14 is transferred from the fifth connection loop 17e of the sample sampling valve 17 to the sixth connection loop. 17f → measuring tube 1.7 g → third connecting hole 17c of sample collection valve 17 → fourth connecting hole 17d → sample discharge port 15, and the sample flows into the measuring tube 17g. Further, the carrier introduced from the carrier inlet 16 is connected to the first connection 17a and the second connection of the sample sampling valve 17.
It is led to the inner chamber 3 of the plasma torch 2 via the connection hole 17b. Furthermore, argon gas and the like are supplied to the outer chamber 5 and the outermost chamber 6 of the plasma torch 2 from a gas supply source (not shown), and a high frequency current is supplied to the high frequency induction coil 6 to generate a high frequency magnetic field around the coil. is formed.

In this state, when the sample collection valve 17 is turned on,
The internal flow path is switched from the solid line connection state in FIG. 1 to the broken line connection state. With such switching, the carrier introduced from the carrier inlet 16 is routed from the first connection 17a of the sample sampling valve 17 to the sixth connection 17f → measuring tube 17g →
Third connection 17c of sample sampling valve 17 → second connection 17b
The sample in the measuring tube 17g is guided to the inner chamber 3 of the plasma torch 2 by the carrier gas. The sample guided to the plasma torch 2 in this way is excited by the high-frequency inductively coupled plasma 7, and the generated ions are guided to a mass spectrometer through an interface consisting of a nozzle and a skimmer, where they are electrically detected and the amount of ions is detected. By precisely measuring the elements, the elements to be measured in the sample can be analyzed with high precision.

<Effects of the Invention> According to the embodiments of the present invention as described in detail above, even if the concentration of the component to be measured in the sample is high, the component to be measured may precipitate at the nozzle and the nozzle may become clogged. A high-frequency inductively coupled plasma snowscape analysis device will be realized.

That is, since the sample can be introduced into the plasma torch at the desired analysis timing, the sample is not introduced into the plasma torch 2 during the time before and after analysis is performed, and the nozzle 8 is filled with the component to be measured in the sample, as in the conventional example. There will be no more blockage. In addition, since only the carrier gas is introduced into the nozzle 8 while the sample is not introduced into the plasma torch 2, the nozzle 8 has the effect of being cleaned with the carrier gas during that time, and as a result, the nozzle 8 becomes clogged with the component to be measured. This can be completely prevented from happening. Furthermore, by making the switching time of the sample switching valve variable, there is an advantage that the amount of sample introduced can be changed arbitrarily.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the main part configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the main part configuration of a conventional example showing the main parts of the conventional example. 1... Main body of high frequency inductively coupled plasma mass spectrometer, 2... Plasma torch, 3... Inner chamber of plasma torch, 4...
Outer chamber of plasma torch, 5...Outermost chamber of plasma torch, 6...High frequency induction coil, 7...High frequency induction plasma, 8...Nozzle , 9... Skimmer 10... Center chamber 11... Mass spectrometry section, 2... Secondary electron multiplier, 13... Arithmetic processing unit, 4...sample gas inlet, 5...carrier gas inlet 6...carrier gas outlet, 7...sample sampling valve

Claims (4)

[Claims] (1) The sample guided into the plasma torch is excited using high-frequency inductively coupled plasma, and the generated ions are guided to a mass spectrometer detector through an interface consisting of a nozzle and a skimmer for detection. An analyzer for analyzing an element to be measured, characterized in that the sample is sent to a sample sampling valve to fill a metering tube with a constant internal volume, and then the sample sampling valve is switched and a carrier gas is guided into the internal chamber of the plasma torch. High frequency inductively coupled plasma mass spectrometer. (2) The sample sampling valve has first to sixth connection ports and a metering tube with a constant internal volume, and the first, third, and fifth connection ports are connected to a second connection port, respectively.
, fourth and sixth connection ports, respectively, and the first, third and fifth connection ports are connected to the sixth, second and fourth connection ports, respectively.
The high-frequency inductively coupled plasma mass spectrometer according to claim 1, wherein the high-frequency inductively coupled plasma mass spectrometer is configured to be alternately switched between the second state and the second state in which the connection ports are respectively connected. (3) The sample sampling valve is composed of two four-way switching valves that sandwich the measuring tube; a first state in which the sample is introduced into the measuring tube, and a first state in which the sample is guided directly to the plasma torch by bypassing the carrier; A high-frequency inductively coupled plasma mass spectrometer according to claim 1, wherein the second state in which the flow is performed is alternately switched. (4) A patent claim in which the sample collection valve is a three-way switching valve and is configured to be alternately switched between a first state in which the sample is directly introduced to the plasma torch and a second state in which the carrier is directly introduced to the plasma torch. A high frequency inductively coupled plasma mass spectrometer according to scope (1).