JP2007333611A - Chemical analysis apparatus and chemical analysis method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical analysis apparatus capable of overcoming the drawbacks of a conventional tube pump, capable of precisely quantitatively supplying a solution, and capable of securing the accuracy even when air bubbles are contained or generated in the solution. <P>SOLUTION: The chemical analysis apparatus includes a tube pump having a rotation amount detection means for converting a rotation amount to an electric signal; an analysis tank having a sensor capable of reading physicochemical characteristics of the solution by the electric signal; a suction line disposed on a suction side of the tube pump, communicated with a sample tank, a reagent container or a water container, and having a plurality of valves for selectively feeding a sample, a reagent or water; and a delivery line communicating a delivery side of the tube pump and the analysis tank, and having a gas intrusion detection means for detecting gas contained in the liquid and converting it to the electric signal. The chemical analysis apparatus further includes a calculating means for performing AND operation of the electric signal from the rotation amount detection means and the gas intrusion detection means, and an analysis means for associating the result of the calculating means with the electric signal from a sensor and calculating the ingredient concentration of the sample. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a chemical analyzer, and more particularly, to a chemical analyzer capable of accurately collecting and analyzing a sample or the like using a solution quantitative supply device capable of accurately supplying a solution using a tube pump. The present invention relates to an analyzer and a chemical analysis method using the same.

  In conventional chemical analyzers, when performing chemical analysis and measurement with high accuracy, a tube pump has been used to accurately inject a small amount of reagent solution. However, since the tube pump presses the tube with a roller or the like and discharges the liquid, the tube may elongate due to long-term use, and the discharge amount per unit time may change. The change in the discharge amount over time causes an error when used in a liquid addition mechanism in quantitative chemical analysis, and its application has been limited.

  In addition, if the sample solution or reagent is subject to pressure change, contact friction, temperature change, etc., and bubbles are likely to be generated inside it, bubbles may be generated inside the pipe due to the pressure of the roller, etc., and this may cause the accuracy of the discharge amount to decrease It was.

  Therefore, in high-precision chemical analysis and measurement that requires accurate quantification of liquids, it is necessary to rely on a complicated and expensive liquid addition mechanism such as a cylinder type pump, or with a precise balance instead of liquid volume. The mass had to be accurately weighed and added to the analytical system.

  In recent years, in order to solve such problems of conventional tube pumps, particularly the problem of changes in transport volume due to aging of tubes, the amount of liquid fed from the tube pump is converted into the required storage time by a constant volume weighing means, By determining the dispensing time in this way, an apparatus that can ensure a predetermined dispensing amount with high accuracy has been developed (see Patent Document 1).

  However, since this apparatus manages a predetermined dispensing amount according to the dispensing time, it does not guarantee the accuracy of the dispensing amount when bubbles are generated in the sample solution or reagent.

JP-A-5-80060

  In view of the above situation, an analyzer that can overcome the disadvantages of the conventional tube pump, can accurately supply a solution, and can guarantee the accuracy even when bubbles are mixed in or generated in the solution. Development is desired, and it is an object of the present invention to provide such an analyzer.

  The present invention solves the above-described problem, and provides a tube pump provided with a rotation amount detecting means for converting a rotation amount into an electrical signal, and a sensor capable of reading the physicochemical characteristics of a solution with an electrical signal. The analysis tank provided, the suction line of the tube pump, the suction line that communicates with the sample tank, the reagent container or the water container and has a plurality of valves for selectively feeding the sample, reagent or water, and the tube pump A chemical analyzer having a discharge line provided with a gas mixing detection means for detecting a gas mixed in the liquid and converting it into an electrical signal. Calculation means that performs an AND operation on the electrical signals from the rotation amount detection means and the gas contamination detection means, and relates the result of the calculation means to the electrical signal from the sensor to calculate the component concentration of the sample. Is a chemical analysis apparatus comprising and a analysis means for.

  The present invention also provides a tube pump, a suction line installed on the suction side of the tube pump, having a plurality of valves in communication with a sample container, a reagent container or a water container, and selectively feeding a sample, reagent or water, and A chemical analysis method using a chemical analysis apparatus having an analysis tank having a sensor installed at an end of a discharge line of the tube pump and capable of reading a physicochemical characteristic of a solution with an electric signal, The sample or reagent is fed into the analysis tank while opening and closing the valve, and the changes in the physicochemical characteristics of the solution in the analysis tank are read with an electrical signal, and the rotation amount of the tube pump and the middle of the discharge line are provided. Calculate the amount of liquid delivered from the electrical signal of the gas contamination detection means, and analyze the concentration of the sample by correlating the amount of liquid delivered with the changes in the physicochemical properties of the solution in the analysis tank It is a chemical analysis method comprising Rukoto.

  According to the present invention, since the amount of bubbles generated when a sample or the like is collected by a tube pump can be reflected in the liquid collection amount, it is possible to accurately feed the sample or reagent into the analysis tank. .

  Further, in the apparatus of the present invention, since the sample or reagent is fed by the same tube pump, even if the transport amount due to aging of the tube changes, there is no problem and the analysis can be performed accurately.

  Hereinafter, the present invention will be described in more detail with reference to the drawings showing an embodiment of the present invention, but the present invention is not limited thereto.

  FIG. 1 is a drawing schematically showing one embodiment of the configuration of the chemical analyzer of the present invention. In the figure, 1 is a chemical analyzer, 2 is a tube pump, 3 is a rotation amount detection means, 4 is a suction line, 5 is a discharge line, 6 is a gas contamination detection means, 7 is an analysis tank, 8 is a sensor, 9 is a valve Respectively. Further, 10 is a sample container, 11 is a reagent container, 12 is a pure water container, 13 is a computer, 13a is a calculation means, 13b is a component calculation means, 14 is a discharge port, and 15 is a drainage pump.

  As shown in FIG. 1, the chemical analyzer of the present invention is provided with a suction line 4 on the suction side of the tube pump 2 and a discharge line 5 on the discharge side. Among them, the sample tank 10, the reagent container 11 and the pure water container 12 are communicated with the suction line 4 through valves 9a, 9b and 9c, and necessary samples or reagents are described later by opening each valve. The liquid can be fed into the analysis tank 7, and the analysis tank 7 can be washed with pure water. In addition, although the reagent container 11 in FIG. 1 is one, it cannot be overemphasized that this may be made into multiple according to an analysis object reagent.

  In the middle of the discharge line 5, a gas mixing detection means 6 is provided, and an analysis tank 7 having a sensor 8 is provided at the end thereof. As the gas mixing detection means 6, a bubble sensor or the like is used, and information on the presence or absence of bubbles here is converted into an electrical signal and sent to the calculation means 13a.

  As a motor that rotationally drives the rotor of the tube pump 2, a mechanism that can accurately grasp the rotation angle of the tube pump rotor, such as a servo motor, a DC motor with an encoder, or a brushless DC motor, can be provided. Anything other than this can be used as long as it can accurately determine the rotation angle of the rotating shaft of the motor.

  The tube pump 2 is provided with a rotation amount detecting means 3 for measuring the rotation amount. As the rotation amount detecting means 3, a rotary encoder or the like directly connected to the drive shaft of the rotor of the tube pump 2 is used. Information on the rotation amount of the rotor is converted into an electric signal, for example, an electric pulse indicating the rotation angle of the rotor. And sent to the calculation means 13a. In this calculating means 13a, a logical product operation with the electric signal from the gas mixing detection means is performed to obtain an electric signal indicating the actual liquid feeding amount. For example, as shown in FIG. 2, when an electric signal A of the rotation amount from the rotation amount detection means 3 and an electric signal B from the gas mixture detection means 6 are sent, the part where the liquid is actually sent Only the electric signal of the rotation amount corresponding to is made effective, and the electric signal C becomes the actual liquid feeding amount.

  On the other hand, in the analysis tank 7 to which the sample or reagent has been sent, the sensor 8 reads changes in the physicochemical characteristics of the solution resulting from these results, and converts them into electrical signals. As this physicochemical property change, changes in pH, color, transparency, redox potential, conductivity, ion concentration, temperature, etc. can be used. As sensor 8, a pH sensor, redox potential sensor, temperature sensor can be used. In addition, one or a combination of two or more absorbance sensors, color sensors, and the like can be used. For example, if the sample solution to be analyzed is alkaline, an acidic solution may be added as a reagent, and the change in the mixed solution may be read by pH. If the sample to be analyzed is a reducing solution, the reagent may be oxidized. What is necessary is just to read the change of the mixed solution by oxidation-reduction potential, adding a solution.

  Finally, the solution concentration of the sample to be analyzed is determined by associating the actual liquid delivery amount obtained above with the physicochemical property change of the solution obtained above by the component calculation means 13b. Can do. That is, in the apparatus of the present invention, the tube pump 2 is used and the amount of bubbles can be subtracted, so that the amount of sample and reagent to be fed can be accurately determined. Therefore, if a reagent whose concentration is accurately determined is used, the concentration of the sample can be accurately determined.

  In the apparatus of the present invention, the tube pump 2 is used. However, since the sample and the reagent are fed using the same tube, the sample and the reagent can be used even if the tube changes over time due to long-term use. There is no change in the amount, and the measurement is not affected. That is, the relationship between the rotation angle of the tube pump 2 and the stoichiometric concentration will be described as follows.

  First, let m be the rotation angle of the rotor excluding bubbles necessary for sampling. Let Vr be the volume transported by the tube pump 2 per unit angle. The sum of the rotation angles at which the tube pump rotor is driven until the reagent reaches a predetermined pH is Σp. Further, when the reagent concentration N, the factor thereof is f, and the equivalent coefficient for the desired chemical species is E, the stoichiometric concentration C can be expressed by the following equation.

[Formula 1]
C = (E × f × Vr × Σp) / (Vr × m)
C = (E × f × Σp) / m

  As is apparent from this equation, the volume Vr that the tube pump transports per unit angle is offset. The characteristic value that gradually changes during long-term operation of the tube pump is Vr. However, as is apparent from this equation, the present invention is not affected by changes in Vr. In addition, the reproducibility of the above equation is improved by using a rotation angle proportional to the volume of the true liquid excluding the sample and reagent bubbles.

  Next, an embodiment of a method for analyzing using the chemical analyzer of the present invention will be described.

  First, only the electromagnetic valve 9a is opened to drive the tube pump 2 in order to collect a sample liquid quantitatively. The sample sent in this state is opened and discharged through the three-way solenoid valve 9d until the sample liquid is completely replaced with the liquid remaining in the piping path (suction line 4 and discharge line 5). . Next, the three-way solenoid valve 9d is switched to the analysis tank 7 side in a timely manner, and quantitative sampling is started. Here, a signal C corresponding to the amount of the liquid excluding the bubble passing through the signal B of the gas mixing detection means 6 and the rotation amount signal A of the rotor drive shaft is obtained by a logical product operation.

  When the sample in the analysis tank 7 is small and does not reach the sensitive site of the sensor 8, the valve 9 a is closed, the valve 9 c is opened, and pure water is collected from the pure water container 12 by the tube pump 2. Also in this case, pure water is poured from the discharge port 16 for a certain period of time and then injected into the analysis tank 7. This completes the sample collection process.

  Next, a predetermined amount of reagent is added from the reagent container 11 to the analysis tank 7 and stirred by the stirrer 17. In this case as well, as with sample collection, only the solenoid valve 9b is opened and the reagent is transported from the tube pump 2. Also in this case, for the first fixed time, the reagent is poured out from the discharge port 16 in the same manner as described above.

  A certain amount of this reagent is added to the analysis tank 7, and the physicochemical change of the liquid after being mixed by the stirrer 17 is measured by the sensor 8. Measurement and reagent addition are repeated until the physicochemical change reaches a certain value. The stoichiometric concentration of the sample can be obtained from the amount of reagent required to reach the predetermined value and the amount of sample collected. After the concentration is obtained, the liquid in the analysis tank 7 is drained by the drainage pump 16 and the series of operations is completed.

  Note that the computer 13 controls and calculates each device of the device of the present invention. A printer, a display device, and a keyboard may be incorporated in the computer 13 for density display and individual operation of each device.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not restrict | limited at all by these Examples.

Example 1
In recent years, the present invention was used to analyze perhydrosulfuric acid-based etchants used in electronic component manufacturing processes. This perhydrosulfuric acid-based etching solution uses an aqueous hydrogen peroxide solution as its oxidant, and oxygen bubbles may be generated in the solution due to a pressure change or contact stimulus accompanying the transport of the solution. In addition, because of its oxidizing nature and high acidity, the performance change of the tube pump was severe due to problems such as thinning of the resin tube used in the tube pump.

  In this example, the apparatus shown in FIG. 1 was used. Moreover, in order to confirm the effect of invention, the apparatus which removed the bubble detector (gas mixing detection means) intentionally as a comparison was also used. The change in analytical value for one month in each continuous operation was compared in the technique used. The results are shown in Table 1. In the present example, the analytical value means the volume percentage of hydrogen peroxide in the etching solution.

  As is clear from this result, in the comparison apparatus without air bubble detection, values lower than the standard were occasionally found. At this time, it was also confirmed visually that the sample flowed into the analysis tank in a state where bubbles were included.

Example 2
A high-concentration etching solution was analyzed at a rate of 12 times a day for one month, and the fluctuation range and coefficient of variation were examined. Condition A (present invention) using the analyzer of the present invention, and Condition B (prior art) adopting an analysis mechanism that transports the sample and reagent by separate tube pumps without using the apparatus of the present invention Compared. In the confirmation test before and after the operation for one month, a low-concentration etching solution with little influence of bubbles was used as a sample solution for repeated analysis.

  From this result, when comparing the present invention with the prior art, it can be seen that there is no significant difference in the stability of the analytical value before and after operation, but the analytical value tends to increase overall in the prior art. On the other hand, in the analyzer employing the present invention, no significant fluctuation of the analysis value was observed.

  According to the apparatus of the present invention, it is possible to accurately measure the concentration of a sample that easily generates bubbles. Therefore, it can be widely used as an apparatus for automatically analyzing various processing solutions used in the chemical industry, for example, the metal surface treatment field.

It is drawing which shows the structure of this invention chemical analyzer. It is drawing which shows the detection method of the actual liquid feeding amount in this invention chemical analyzer. In the figure, A indicates a rotation amount signal, B indicates a bubble presence / absence signal, and C indicates an actual liquid supply amount signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ...... Chemical analyzer 2 ...... Tube pump 3 ...... Rotation amount detection means 4 ...... Suction line 5 ...... Discharge line 6 ...... Gas mixing detection means 7 ...... Analysis tank 8 ...... Sensor 9 ...... Valve 10 ... ... Sample container 11 ... Reagent container 12 ... Pure water container 13 ... Computer 13a ... Calculation means 13b ... Component calculation means 14 ... Discharge port 15 ... Drain pump 16 ... Motor 17 ... Stirrer
more than

Claims (2)

  Tube pump with rotation amount detection means for converting rotation amount into electrical signal, analysis tank with sensor capable of reading physicochemical characteristics of solution with electrical signal, installed on suction side of tube pump A sample tank, a reagent container or a water container, a suction line having a plurality of valves for selectively feeding the sample, reagent or water, and a discharge side of the tube pump and the analysis tank, and a liquid A chemical analyzer having a discharge line provided with gas mixture detection means for detecting gas mixed in and converting the gas into an electrical signal, and further comprising an electrical circuit from the rotation amount detection means and the gas mixture detection means. A chemical analysis apparatus comprising: arithmetic means for performing a logical AND operation on a signal; and analysis means for calculating a component concentration of a sample in association with a result of the arithmetic means and an electrical signal from a sensor. Tube pump, suction line installed on the suction side of the tube pump, communicating with the sample container, reagent container or water container, and having a plurality of valves for selectively feeding the sample, reagent or water, and discharge of the tube pump A chemical analysis method using a chemical analysis apparatus having an analysis tank having a sensor installed at an end of a line and capable of reading a physicochemical characteristic of a solution with an electrical signal, wherein the plurality of valves are opened and closed. While the sample or reagent is fed into the analysis tank, the changes in the physicochemical properties of the solution in the analysis tank are read with an electrical signal, and the amount of rotation of the tube pump and detection of gas contamination provided in the middle of the discharge line The solution concentration is calculated from the electrical signal of the means, and the concentration of the sample is analyzed by correlating the amount of solution flow with the change in the physicochemical properties of the solution in the analysis tank. Chemical analysis methods for.

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