JP5939816B2 - ICP emission spectroscopic analyzer and method for analyzing sample containing organic solvent - Google Patents

Description

  The present invention relates to an ICP (Inductively Coupled Plasma) emission spectroscopic analysis apparatus, and more particularly to an ICP emission spectroscopic analysis apparatus provided with a cooling mechanism in a part of an aerosol transport path and a method for analyzing a sample containing an organic solvent using the same. .

  A high-frequency inductively coupled plasma atomic emission spectrometer is generally configured as shown in FIG. That is, in FIG. 2, argon gas is supplied from an argon gas supply source 3 to the outer chamber 1b and the outermost chamber 1c of the plasma torch 1 through the gas regulator 2. On the other hand, the solution sample in the sample tank 5 is atomized in the spray chamber 4 and is carried into the torch inner chamber 1a as an aerosol together with the carrier gas. The carried aerosol is ionized element by element in the plasma flame, and is dispersed and detected in the spectrometer 8.

  When measuring trace elements in an organic solvent using such an apparatus, if the organic solvent is introduced into the apparatus as it is, the plasma may become unstable or misfire may occur. Therefore, since it is essential to make the sample into an aqueous solution, complicated pretreatment is required. However, it is difficult to measure a trace component in an organic solvent with an aqueous solution because of contamination due to pretreatment and a decrease in sensitivity due to a high dilution rate. For this reason, a method for stably measuring an organic solvent directly as a sample solution has attracted attention in recent years, and various studies have been made.

  An improved method generally used in measuring organic solvents is described. FIG. 3 is a simplified diagram of the apparatus from the spray chamber to the torch. A nebulizer 9 that introduces Ar gas and a sample solution and atomizes the sample solution, a chamber body 10, a cooling block 11a, a cooling mechanism 12a, a drain carry-out port 13, a plasma chamber 14, and a lead-out port 15 are included. This configuration discloses a method of cooling the cooling block 11a to keep the chamber body 10 at a constant temperature.

  Further, although not an ICP emission spectroscopic apparatus, there is a similar technique as shown in FIG. In Patent Document 1, a cooling block 11c is provided in the conveyance path 16b in the vicinity of the chamber main body 10 and the chamber outlet 15 provided with the cooling block 11a, and the cooling block 11c is cooled to a temperature lower than that of the chamber main body 10, thereby It reports that measurement is possible. However, the verification of the effect on the highly volatile organic solvent and the verification of the measurement accuracy have not been performed.

  According to the conventional chamber having such a configuration, the water vapor in the chamber body 10 falls from the drain carry-out port 13, but the micro-aerosol generated by the atomization is led out from the lead-out port 15 and passes through the transport path 16. And reaches 1a in the plasma torch. At this time, the transfer path 16a in the vicinity of the plasma torch passes through the plasma chamber 14. Since the atmosphere inside the plasma chamber 14 is higher than the room temperature due to the influence of plasma heat, the carrier path 16a in the vicinity of the plasma torch reaches the temperature in the plasma chamber 14, and therefore the carrier gas flowing through the carrier path 16a. The aerosol is heated to the temperature of the transport path 16a.

Japanese Patent Laid-Open No. 05-087779

  In the conventional example of FIG. 3, when the sample is a highly volatile organic solvent, the solvent in the aerosol becomes a gas when passing through the transport path 16a near the torch, and the volume expands in proportion to the temperature. Although the gas flow rate introduced into the plasma is originally controlled by the carrier gas, a large amount of uncontrollable gas generated from the aerosol reaches the plasma flame. For this reason, the measurement accuracy deteriorates due to instability of the flame, and a phenomenon occurs in which measurement cannot be performed due to misfire. Therefore, when measuring a highly volatile organic solvent, it is necessary to suppress the heating phenomenon of the aerosol passing through the transport path 16a due to the temperature rise in the plasma chamber 14 as a means for improving the measurement accuracy. However, in the conventional configuration of the cooling block 11c in the transport path 16b in the vicinity of the chamber body 10 and the outlet port 15, it is difficult to maintain the plasma in a stable state, and fluctuations in emission intensity and analysis value are large. For this reason, there has been a demand for the development of a device that can measure stably and accurately and a measurement method.

  The present invention has been made in view of the background art as described above, and provides an ICP emission spectroscopic analysis apparatus and analysis method capable of analyzing trace components in organic solvents with improved measurement accuracy. is there.

An ICP emission spectroscopic analyzer that solves the above problems includes a chamber for atomizing a sample containing an organic solvent, a plasma torch for converting the atomized sample into plasma, a plasma chamber for storing the plasma torch, A transport path for transporting the atomized sample from the chamber to the plasma torch, a first cooling means for cooling the chamber, and a second cooling means for cooling the transport path , The plasma torch has a first torch chamber through which the atomized sample flows, and a second torch chamber through which argon gas for air-cooling the atomized sample flows, and the second cooling means includes the of the conveying path, characterized Rukoto of having a cooling section portion, the water cooling between the chamber a the plasma chamber and the plasma torch.

  ADVANTAGE OF THE INVENTION According to this invention, the ICP emission-spectral-analysis apparatus and analysis method which can perform the analysis of the trace component in an organic solvent by improving a measurement precision can be provided.

It is the schematic which shows one embodiment of the ICP emission-spectral-analysis apparatus of this invention. It is a block diagram which shows the ICP emission spectroscopy apparatus of a prior art example. It is a simplified diagram showing from the chamber to the torch of the ICP emission spectrometer of the conventional example. It is a simplified diagram showing a cooling mechanism of a conventional ICP emission spectroscopic device.

  Hereinafter, embodiments of the present invention will be described in detail.

  An ICP emission spectroscopic analysis apparatus according to the present invention is an ICP emission spectroscopic analysis apparatus that performs excitation light emission or the like by high-frequency inductively coupled discharge. A chamber main body 10 for atomizing a sample containing an organic solvent; A plasma torch 1 for converting the atomized sample into plasma, a transport path 16 for transporting the atomized sample to the plasma torch 1, a cooling block 11 a for cooling the chamber body 10, and a transport path A cooling block 11b that cools the conveyance path 16a in the vicinity of the plasma torch, a cooling mechanism 12a for controlling the temperature of the cooling block 11a, and a cooling mechanism 12b for controlling the temperature of the cooling block 11b. Features.

  Further, an ICP emission spectroscopic analysis apparatus according to the present invention is an ICP emission spectroscopic analysis apparatus that performs excitation light emission or the like by high frequency inductively coupled discharge. A chamber main body 10 for atomizing a sample containing an organic solvent; and the chamber main body 10 A plasma torch 1 for converting the atomized sample into plasma, a transfer path 16 for transferring the atomized sample to the plasma torch 1, and a cooling block 11a for cooling the chamber body 10; A cooling block 11b that cools a transfer path 16a that is a part of the transfer path 16 and is in the plasma chamber 14, a cooling mechanism 12a for temperature control of the cooling block 11a, and cooling for temperature control of the cooling block 11b And a mechanism 12b.

  An analysis method according to the present invention is a method of analyzing a sample containing an organic solvent by an ICP emission spectroscopic analysis method that performs excitation light emission or the like by high frequency inductively coupled discharge, and the sample containing the organic solvent is cooled to room temperature or lower. Introducing into the chamber body 10 and atomizing the sample containing the organic solvent; and conveying the sample containing the atomized organic solvent to the plasma torch 1 by the conveyance path 16; In the process, the transport path 16a passing through the inside of the plasma chamber 14 is cooled, and this is a method for analyzing a sample containing an organic solvent.

  A specific embodiment will be described with reference to FIG. FIG. 1 is a schematic view showing an embodiment of the ICP emission spectroscopic analyzer of the present invention. In FIG. 1, the cooling mechanism 12a cools the cooling block 11a using the water cooling type cooling mechanism by a hydroalcoholic liquid mixture. The cooling block 12b for cooling the aerosol carry-in path 16a passing through the plasma chamber 14 uses a water-cooled cooling mechanism 12b using a hydroalcoholic liquid mixture. The cooling temperature need not be supercooled below the chamber temperature. Moreover, since the conveyance path 16b in the vicinity of the chamber is at room temperature, it is desirable to adjust the cooling block 12b with the cooling mechanism 12b so that the cooling block 12b is below room temperature. Therefore, the cooling temperature range of the transfer path 16b in the plasma chamber 14 is preferably not less than the chamber cooling temperature and not more than room temperature. The cooling mechanisms 12a and 12b are not particularly limited as long as they can be adjusted to the target temperature regardless of whether they are water-cooled or gas-cooled.

  According to the present invention, volume expansion due to vaporization of an aerosol of a highly volatile organic solvent can be suppressed. It can be introduced into the plasma torch while maintaining the aerosol state of the organic solvent. In the plasma torch, argon gas flows through the torch outermost chamber 1c and the torch outer chamber 1b, so that the aerosol flowing through the torch inner chamber 1a is charged into the plasma while being cooled by air. Since it enters the plasma while being rectified in one direction, it is possible to suppress unstable factors of the plasma flame and maintain a stable flame for a long time. As a result, the measurement accuracy is improved, and the trace components in the organic solvent can be analyzed.

Example 1
FIG. 1 is a schematic diagram of a basic ICP emission spectroscopic analyzer of the present invention. The chamber body 10 was cooled to −10 ° C. using the cooling mechanism 12b by water cooling. Furthermore, the conveyance path 16a in the vicinity of the plasma torch was cooled using cooling water adjusted to 0 degrees. As the ICP apparatus, a CIROSCCD type manufactured by Spectro Co., Ltd. was used.

(Comparative Example 1)
The configuration of Comparative Example 1 will be described with reference to FIG. The chamber body 10 was cooled with cooling water adjusted to −10 ° C. using a cooling mechanism 12b by water cooling. Furthermore, the conveyance path 16b of the outlet port of the chamber was cooled using cooling water adjusted to 0 degrees.

(Comparative Example 2)
The configuration of Comparative Example 2 will be described with reference to FIG. The chamber body 10 was cooled with cooling water adjusted to −10 ° C. using a cooling mechanism 12b by water cooling.

  As the organic solvent sample, a mixed standard solution IV manufactured by Kanto Chemical Co., dissolved in THF to 10 ppm was used. The measurement target elements were Na, Mg, Ca, Zn, Cu, and Ar, and the measurement target emission wavelength was shown after the element symbol (unit: nm). The organic solvent sample in which the standard solution was dissolved was introduced into the ICP devices of Examples and Comparative Examples, and the measurement was repeated 10 times, and the average relative standard deviation (RSD value) was calculated from the quantitative values obtained.

  The measurement results of the average relative standard deviation value of each element in the examples and comparative examples are shown in Table 1 below.

  As shown in Table 1, the relative standard deviation value of Example 1 was 4 or less for all elements. With the configuration of the present invention, the measurement accuracy of a highly volatile organic solvent could be improved. Furthermore, it was confirmed that the plasma was stable for a long time even when THF was continuously introduced after the measurement.

  As shown in Table 1, the relative standard deviation values of Comparative Examples 1 and 2 were of the same accuracy. Further, THF was continuously introduced after the measurement, but the flame became unstable and misfired, and long-term stability could not be secured.

  The present invention can be used for analysis of trace components in organic solvents.

DESCRIPTION OF SYMBOLS 1 Plasma torch 1a Torch inner chamber 1b Torch outer chamber 1c Torch outermost chamber 2 Gas regulator 3 Argon gas supply source 4 Spray chamber 5 Sample tank 6 High frequency induction coil 7 Plasma power source 8 Spectrometer / detector / calculation processing 9 Nebulizer 10 Chamber body 11a Cooling block 11b Cooling block 11c Cooling block 12a Cooling mechanism 12b Cooling mechanism 13 Drain carry-out port 14 Plasma chamber 15 Deletion port 16 Transfer route 16a Transfer route near the plasma torch 16b Transfer route near the discharge port

Claims (1)

A chamber for atomizing a sample containing an organic solvent;
A plasma torch for converting the atomized sample into plasma;
A plasma chamber containing the plasma torch;
A transport path for transporting the atomized sample from the chamber to the plasma torch;
First cooling means for cooling the chamber;
A second cooling means for cooling the transport path,
The plasma torch has a first torch chamber through which the atomized sample flows, and a second torch chamber through which an argon gas for air-cooling the atomized sample flows.
Said second cooling means of the transport path, the portion between the chamber a said plasma chamber and said plasma torch, ICP emission spectroscopy, characterized in Rukoto of having a cooling section for water cooling the apparatus.

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