JPS62298748A - Icp analysis - Google Patents

Abstract

PURPOSE:To reduce analysis time significantly, by turning a changeover valve to a sample discharge position when a sample is to be changed and the flow rate of a gas supplied into a chamber is increased. CONSTITUTION:When one sample is to be analyzed, a control signal is provided from a controller 34 to supply power to an induction coil 10 through a matching box 12 from a high frequency power source 14 and a cooling gas and a plasma gas are supplied to a plasma torch 2 to maintain a plasma. Consequently, a sample 16 sucked up by a pump 18 is atomized into a chamber 24 and introduced into the torch 2 through a changeover valve 4 to cause light emission. Then, when different samples are to be analyzed, a signal is provided to a motor 30 from a controller 32 to turn the valve 4 to the sample discharge position and the flow rate of a carrier gas supplied to the chamber 24 is increased by a controller 28 to match the timing thereof.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (a) Industrial Application Field The present invention relates to an ICP (high frequency inductively coupled plasma) analysis method, and in particular to a method for reducing analysis time for multiple samples of different types. Regarding shortening methods.

(b) Prior art and its problems In general, ICP analyzers analyze liquid samples, and compared to spark and arc emission spectrometers that analyze solid samples, plasma is stationary. It has the advantages of being stable and having high analytical accuracy.

By the way, in such an ICP analyzer, it may be necessary to continuously analyze a plurality of samples of different types. In such cases, conventional sample introduction systems have a large time constant, so it took several minutes to analyze one sample.

In other words, the time required to cause the sample to emit light with the plasma torch is actually a short time of about 10 to 20 seconds, but the test 1 introduction system that introduces the sample into the plasma torch is newly introduced from the sample analyzed previously. It took some time for the sample to be completely replaced. This includes the time required to replace the sample 1 in the sample suction tube and the time required to replace the sample in the chamber.

As described above, in the past, the cleaning time required to stabilize the sample introduction system was extremely long compared to the time required to cause the sample to emit plasma, reducing the analysis efficiency as a whole.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to significantly shorten the analysis time when analyzing multiple samples of different types. .

(c) Means for Solving the Problems In order to achieve the object described in 1, the present invention provides a sample flow path switching valve provided between the atomization chamber and the plasma torch. Applying the ICP analyzer, during trial 1'4 analysis, the switching valve was switched to the plasma torch side to introduce the sample atomized in the diember into the plasma torch, while when replacing the trial it, the switching valve was switched to the plasma torch side to discharge the sample. At the same time as switching to the side, the flow rate of gas supplied into the chamber is increased at the same timing as when the sample is analyzed.

(D) Embodiment FIG. 1 is a schematic diagram showing the main parts of a TCP analyzer to which the method of the present invention is applied.

In the same figure, numeral 1 indicates the entire device (rcr), and 2 indicates the plasma torch.
A switching valve 4, a cooling waste introduction pipe 1 for pre-cooling, and a plasma gas introduction pipe 8 for maintaining plasma 4 are connected to A1, respectively.

In addition, IO generates a periodontal θU magnetic field and an induction coil, 1
Reference numeral 2 represents a match box for matching the impedance between the main frequency power supplied to the induction coil IO and the load, and 14 represents a high frequency power source for supplying high frequency power to the induction coil 10. Also, 16 is a solution sample, 18 is a solution sample 11. 20 is a suction tube; 22 is a nebulizer for atomizing the solution sample 16; 24 is a chamber for stabilizing the sample 1 atomized by the nebulizer 22; Reference numeral 28 denotes a gas control line for controlling the amount of gas introduced into the plasma torch 2 and the gas flow from the gear rear gas to be supplied to the nebulizer 22. Reference numeral 30 denotes a motor that rotationally drives the switching valve 26; A 34-key chamber controller controls the switching operation of the switching valve 26.
1- High frequency power supply I4, stationary pump 18, gas conditioner)・
The sequence of the roller 28 and the chamber controller 32 is controlled by the sequence controller 1-ra.

-1- Switching valve 4+J: As shown in FIGS. 2 to 4, a first fixed part shrine 40 in which an outlet boat 38 is formed, and an inlet boat 4 of multiple rJICs (four in this example)
2 is provided with a second fixing portion +1'44. Part I
7, the plasma torch 2 is connected to the exit boat 38,
A chamber 24 is connected to one of the artificial boats 42 . The remaining person [1 boat 42 is used as a sample discharge boat. Further, assuming that the first and second fixed parts +4'40.44 are integrated by fixing their respective flanges with bolts 46, a movable member 48 is disposed between both fixed part shrines 40.44. has been done. This movable member 48 has a communication path 5o that communicates the inlet boat 42 and the outlet boat 38 inside.
4- At the same time, a population board 1-42 is installed at the bottom.
A rotating shaft 54 for rotating the I48 (with a J-turn groove 52 and a movable part in the center of the bottom) passes through the second fixing member 44. The drive shaft of the motor 30 is connected to the rotary shaft 54.

Next, apply this ICP analyzer 1. 8. The method of the present invention will be explained.

When analyzing one sample, sequence control signals are sent from the sequence controller 34 to the high frequency power supply 14 and the gas controller 28, respectively! In addition, high frequency power is supplied from the high frequency power supply 14 to the induction coil 10 via the magic box 12, and at the same time, cooling gas and plasma gas are supplied to the plasma torch 2 to accompany the plasma.

Further, gear gas is supplied to the nebulizer 22. Then, the sample 16 sucked up by the stationary pump 18 passes through the suction tube 20 and is transferred to the chamber 2 by the nebulizer 22.
Sprayed within 4 hours. The atomized sample 1i1iJ is introduced into the plasmat 112 via the switching valve 4, whereby the sample is illuminated by the plasma torch 2.

Next, if the sample l:t to be analyzed this time is of a different type from the sample analyzed last time, the sample introduction system including the metering pump 18, suction tube 20, nebulizer 22, and embargo 24 should be prepared in advance for this analysis. It is necessary to clean with a ground sample. To do this, the sample 16 to be analyzed this time is sucked up with the metering pump 18 and then passed through the suction tube 20 to the nebulizer 22.
At the same time, a drive signal is given to the motor 30 from the chamber controller 32 to switch the switching valve 4 to the sample discharge side, and at the same time, the gas is supplied from the nebulizer 22 into the chamber 24 by the gas controller 28 in time with the switching timing. Increase the gas flow rate of the carrier gas used during sample analysis. Since a large amount of the analysis sample will be sprayed into the chamber 24, the chamber 2
Even if a sample that has been analyzed multiple times remains in the sample 4, it will be displaced within a short time by being pushed out by the sample that will be analyzed this time.

The sample from the previous analysis is then passed through one inlet port 42 of the switching valve 4 and the U-shaped groove 52 to the other inlet port 4.
It is discharged from 2. In this case, even if the flow rate of the carrier gas is increased, the gear gas is not introduced into the plasma torch 2, so the plasma torch 2 is maintained in a stable state.

Once the sample introduction system has been completely replaced with the sample to be analyzed this time and stabilized, the switching valve 4 is switched to the plasma torch 2.
side, and introduce the current analysis sample into the plasma torch 2.

(e) Effects As described above, according to the present invention, the analysis time when analyzing multiple samples of different types can be significantly shortened, and therefore the analysis efficiency can be improved. Excellent effects are demonstrated.

[Brief explanation of drawings]

The drawings show an embodiment of the method of the present invention, and FIG. 1 is a schematic configuration diagram showing the main parts of an ICP analyzer to which the present invention is applied, FIG. 2 is a cross-sectional view of a switching valve, and FIG. FIG. 4 is a plan view of the sliding surfaces of the movable part and fixed part of the same valve. 1... ICP analyzer, 2... plasma torch, 4...
...Switching valve, 16...Sample, 24...Chamber.

Claims (1)

[Claims] (1) An ICP analyzer is used in which a switching valve for the sample flow path is provided between the chamber and the plasma torch, and when analyzing the sample, the switching valve is switched to the plasma torch side and the sample is atomized in the chamber. is introduced into the plasma torch, and at the time of sample exchange, the switching valve is switched to the sample discharge side, and at the same time, the gas flow rate supplied into the chamber is increased compared to that during sample analysis. Analysis method.