JPS6324257B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method and apparatus for measuring a specific element in a liquid, and more particularly to a method and apparatus for continuously measuring an element that produces a hydride of the element when an aqueous solution of a chemical species containing the element is electrolyzed. Regarding water quality analysis, trace analysis methods such as spectrophotometry and atomic absorption spectrometry have been established. but,
Many continuous measurement methods have been developed and put into practical use for analyzing components in the atmosphere, but in the field of water quality analysis, continuous analysis methods and methods have been developed for limited pollution indicators such as PH, COD, and TOC. The device is simply being developed and used. In particular, with regard to heavy metals, continuous analysis is difficult due to (1) the influence of coexisting substances, (2) a concentration process is necessary because the content is often very small, and (3) analysis operations tend to be multistage and complicated. A method for measuring this has not yet been realized. Therefore, the current situation is to analyze and measure individual samples collected at spots using methods such as spectrophotometry and atomic absorption spectrometry. However, in water such as wastewater and river water, the distribution of pollutants is not necessarily uniform even when they are in a dissolved state, and not only does it vary greatly from place to place, but it also changes considerably over time. is normal. Therefore, with the conventional method of collecting and analyzing sample liquids at spots, it has not been possible to understand changes in water quality over time. Furthermore, it took too long to obtain analysis results from sample collection, and it was not possible to simultaneously understand changes in water quality. Therefore, it has been difficult to grasp the pollution status of general water bodies such as river water and to accurately monitor the quality of water such as wastewater. Therefore, it is desired to establish a method that allows contaminants in liquid to be analyzed continuously and in a very short time after sample collection. The present inventors strongly felt the above-mentioned need for monitoring arsenic, etc. in wastewater treatment process management and wastewater management, and as a result of repeated research, the present inventors discovered that the continuation of specific elements in the liquid of the present invention We were able to complete the measurement method. The present inventors focused on the fact that when an aqueous solution containing chemical species such as compounds and ions such as arsenic As, selenium Se, and antimony Sb is electrolyzed, hydrides of these elements are generated, and the generated hydrides are used as a carrier gas. It has been found that the above elements in a liquid can be quantitatively measured by guiding the liquid to a detection device using a liquid. That is, an object of the present invention is to provide a method for continuously measuring arsenic, selenium, antimony, etc. present in liquids such as general water bodies and wastewater. That is, to briefly describe the method of the present invention, it is a continuous measurement method for an element in which a gaseous hydride of the element is generated when an aqueous solution of a chemical species containing the element is electrolyzed, and the method comprises: electrolyzing a sample solution; continuously supplying the gas generated in the electrolyzer to the device, continuously guiding the gas generated in the electrolyzer together with the carrier gas to the detection device, and continuously measuring the hydride of the element contained in the gas. This is a continuous measurement method for the specific element in a liquid. The method of the present invention can be applied to arsenic, selenium, antimony, and other elements whose hydrides can be produced by electrolysis and which can be guided to a detection device using a carrier gas. If chemical species such as compounds or ions containing arsenic (), selenium (), or antimony () are present in the liquid subjected to electrolysis according to the present invention, they will be reduced to hydrogen during the electrolysis process. Become a monster. The hydride is transported therewith in gaseous form by means of a carrier gas introduced into the electrolysis cell of the electrolyzer, guided to a detection device and continuously measured qualitatively or quantitatively. The measurement results can be continuously recorded in a suitable recording means, allowing the analyst to monitor water quality fluctuations from time to time. Furthermore, it is easy to automate the process from sample collection to obtaining analysis results, and results can be obtained in a short time. Electrolysis using an electrolyzer is preferably constant current electrolysis. When electrolysis is performed using a constant current, the concentration of the element to be measured in the liquid and the amount of hydride generated show a high correlation, and quantitative analysis can be performed using a calibration curve prepared in advance. A calibration curve can be easily created using standard solutions of known concentrations. In the present invention, it is not necessary that all of the elements to be measured contained in the sample liquid introduced into the electrolyzer be reduced to hydrides. Furthermore, it is not necessary that all of the generated hydride be guided to the detection device by the carrier gas. It is sufficient if there is a certain correlation between the concentration of the element to be measured in the sample liquid and the detection value detected by the detection device, and it is sufficient that there is a certain correlation between the concentration of the element to be measured in the sample liquid and the detected value detected by the detection device, and the supply flow rate of the sample liquid, the electrolysis conditions, the introduction flow rate of the carrier gas, etc. By keeping constant, a highly reliable calibration curve can be easily obtained as described above. Note that arsenic (), selenium (), and antimony () are reduced to gaseous hydrides (AsH ₃ , H ₂ Se, SbH ₃ ) during the electrolysis process, but
Arsenic (V), selenium (), and antimony () are not hydrogenated. Therefore, when attempting to measure total arsenic, total selenium, and total antimony in a sample solution, the sample solution must be reduced in advance to reduce arsenic (), selenium (), and antimony () to arsenic (). ), selenium (), and antimony (). The reduction treatment may be carried out by bringing the sample solution into contact with a suitable reducing agent such as hydrazine, ascorbic acid, or sulfur dioxide, and performing treatments such as heating and cooling. The carrier gas used in the present invention includes nitrogen,
Inert gases such as argon and helium are preferred. Detection devices used in the present invention include luminescence photometry, atomic absorption spectrometry, inductively coupled plasma emission spectroscopy,
Examples include devices that utilize thermal ionization, infrared absorption, etc. Flame photometry and inductively coupled plasma emission spectroscopy have the advantage that two or more elements can be measured simultaneously. Note that if the sample solution introduced into the electrolyzer contains interfering substances, such as metal ions or halogen ions, they may stain the electrode surface due to electrodeposition.
Accurate measurement becomes difficult due to secondary reactions. Therefore, it is preferable to remove the interfering chemical species in advance using an ion exchange resin, chelate resin, or other adsorbent depending on the type of interfering chemical species. Further, a preferable configuration of a continuous measuring device that implements the method of the present invention explained above is as follows. In other words, this device is a continuous measuring device for an element in which a gaseous hydride of the element is generated when an aqueous solution of a chemical species containing the element is electrolyzed, and a sample collecting device that continuously collects a sample liquid. , a dilution device that dilutes the collected sample solution to a concentration suitable for electrolysis, a purification device that removes substances that interfere with electrolysis contained in the collected sample solution, and a dilution device that dilutes the collected sample solution to a concentration suitable for electrolysis. an acid concentration adjustment device that adjusts the acid concentration to a suitable acid concentration, a reduction device that performs a reduction treatment on the collected sample solution, and a sample solution that has passed through the various devices described above is continuously supplied, and the sample is electrolyzed. an electrolyzer equipped with an electrolytic cell that generates a hydride of the element; a carrier gas is continuously supplied to the electrolytic cell, and the gas generated in the electrolytic cell is continuously transferred from the electrolytic cell together with an electrolyzed solution; a carrier gas supply device for discharging; a gas-liquid separation device for separating the electrolyzed liquid and gas discharged from the electrolytic cell; a detection device for continuously measuring the hydride contained in the gas separated from the gas and liquid; It consists of Furthermore, it is convenient to have a mechanism for creating a calibration curve that can supply a standard solution whose concentration of the element to be measured is known to the electrolyzer instead of the sample solution. This mechanism is placed at an appropriate position on the sample flow line after the sample liquid collection device and before the electrolyzer, as long as it can achieve its purpose. FIG. 1 (plan view) and FIG. 2 (elevation view) are diagrams showing an example of an electrolyzer used in the present invention. In the figure, 11 is a roughly rectangular container (electrolytic cell) with an open top, and the side wall 12 is the short side of the rectangular parallelepiped.
A sample liquid introduction tube 13 is connected to the sample liquid introduction tube 13, and a gas-liquid discharge tube 15 is connected to the side wall 14 on the opposite side. The lid 16 is sized to just abut a rectangular flange 17 extending outward from the top end of the container 11;
Due to its shape, it can be installed in an airtight manner, and can be freely attached and detached using bolts 18 and nuts 19. This lid 16 has
A carrier gas introduction pipe 20 is connected thereto, and two electrodes 21 and 22 are provided. The two plate electrodes 21 and 22 are immersed in the sample liquid in the container 11 when the lid 16 is attached to the flange 17.
Further, it is supported by the lid 16 by support rods 23 and 24 so as to be arranged along the longitudinal direction of the container 11. The pair of electrode plates 21 and 22 are preferably made of platinum. These electrodes are connected to predetermined terminals of a constant current power source. Electrolysis produces hydrogen and oxygen in addition to hydrides such as arsenic, but
All of these are carried by the carrier gas and exit from the container through the gas-liquid discharge pipe 15 together with the electrolyzed liquid (liquid that has undergone electrolysis). A vertical pipe 25 following the gas-liquid discharge pipe 15 and a cylindrical container 27 having a drain port 26 on the side constitute a part of the gas-liquid separator. The separated gas is directed upward through the tube 25 to the detection device. The liquid is drained from the drain port 26. The amount of hydride produced from a sample solution containing the element to be measured at a constant concentration depends on the capacity of the electrolytic cell, the electrode area, the distance between the electrodes, the electrolytic current, the flow rate at which the sample solution is supplied to the electrolytic cell, and the acidity of the sample solution. It depends on the concentration, etc., so adjust it appropriately. Among these, the specifications of the electrolytic cell can be chosen arbitrarily, but there are desirable conditions to reduce the power required for electrolysis, downsize the device, and increase the response speed. For example, cell capacity 5 to 20 cm ³ and electrode area 3 to 10 cm ^2. A distance between poles of about 0.3 to 1.0 cm is practical. At this time, when the electrolytic current is set to a constant current in the range of 0.3 to 3 amperes, the concentration of the elements to be measured (arsenic, selenium, antimony) is 0.1 to 10 μg/ml, and the acid concentration is
In the range of 0.5 to 3N and the test liquid supply flow rate of 2 to 20ml/min, the conversion rate to hydride is a good constant value.
There is a good correlation between the concentration of the elements to be measured (arsenic, selenium, antimony) and the detected hydride values. Although the concentration that can be measured by the method of the present invention depends on the sensitivity of the detection device used, the lower limit is about 0.1 μg/ml as the concentration of the test liquid supplied to the electrolytic cell. If the concentration of the element to be measured in the collected sample liquid is too high, it may be diluted in advance to a concentration range suitable for the device used. Therefore,
It can be measured over a wide range from 0.1 μg/ml to saturation concentration. The measurement can be performed qualitatively or quantitatively depending on the detection device used. Semi-quantitative measurements can also be made by emitting a signal when a certain tolerance is exceeded. FIG. 3 is a conceptual representation of an apparatus for carrying out a preferred embodiment of the invention. The present invention will be explained in more detail based on this embodiment. This device includes a sample collection device 1, a calibration curve creation mechanism 10, a dilution device 2 that dilutes the sample to an appropriate concentration, a purification device 3 that removes interfering substances from the solution, and a sample solution that is adjusted to an acid concentration suitable for electrolysis. An acid concentration adjusting device 4 for adjusting, a reducing device 5 for reducing arsenic (), selenium (), and/or antimony () in the liquid, and an electrolyzer 6 are connected to this via a main line 11 for transferring the liquid. connected in order.
The gas-liquid mixture exiting the electrolyzer 6 is led to a gas-liquid separator 8, the gas is led to a detection device 9 and measured, and the liquid is discharged 12 out of the device. Further, a carrier gas supply device 7 is connected to the electrolyzer, and supplies a carrier gas into the electrolytic cell to help transport the hydrides generated therein. Next, each component of the apparatus shown in FIG. 3 will be explained. The sample collecting device 1 includes a metering pump 1A whose pumping force is variable according to the flow rate of the liquid to be measured 13, a filter 1B for removing solids, and an overflow tank 1C for sampling. Samples are continuously collected by this sample collecting device, and in normal conditions, they are constantly sent to the diluting device 2 and beyond at a predetermined flow rate via the switching pot 10C. The diluter 2 includes a mixing tank 2D and a liquid sending pump 2C that sends the sample to the mixing tank, and further includes a pure water tank 2A and a metering pump 2B that supplies pure water to the mixing tank 2D. The sample solution can be diluted to a desired ratio by adding pure water at a constant flow rate. Dilution is performed so that the concentration of the element to be measured falls within a preferable concentration range for the electrolyzer 6, and the liquid sending pump 2C,
And the flow rate of the liquid fed by the metering pump 2B is adjusted in advance. In the example shown in FIG. 3, dilution is performed in one stage, but if the dilution rate is large, it is desirable to divide the dilution into several stages to reduce errors. The diluted sample is continuously sent to the purification device 3 at a predetermined flow rate by the liquid sending pump 2E. The purification column 3A can also have a multi-stage column structure filled with the same or different adsorbents depending on the type and number of interfering chemical species. The acid concentration adjustment device 4 has a mixing tank 4C that receives the sample liquid that has passed through the purification device 3, and is also equipped with a metering pump 4B that supplies sulfuric acid at a constant flow rate from a tank 4A containing sulfuric acid at a predetermined concentration to the mixing tank 4C. I'm awake. The acid concentration of the liquid to be measured is measured in advance, and the flow rate of the liquid fed by the metering pump 4B is adjusted so as to obtain the desired acid concentration. Alternatively, the acid concentration of the collected sample or diluted sample may be measured using a PH meter or the like, and the supply flow rate of sulfuric acid may be automatically controlled according to the output. The sample liquid that has passed through the acid concentration adjusting device 4 has an acid concentration suitable for electrolysis. The reducing device 5 includes a reducing agent tank 5A and a metering pump 5B that supplies the reducing agent to the mixing tank 5C.The sent sample liquid is stirred and mixed with the reducing agent in the mixing tank 5C, and further includes a water bath 5D. is sent to and heated. When arsenic (), selenium (), and antimony () are present in the liquid, they are reduced and converted to arsenic (), selenium (), and antimony (). The reduced liquid is lowered to an appropriate temperature via a cooler 5E and sent to the next electrolyzer 6. The electrolyzer 6 is as shown in FIGS. 1 and 2, and is composed of an electrolytic cell 6A having a pair of electrodes and an electrolytic power source 6B, and is further supplied with carrier gas from a carrier gas supply device 7. ing. The device 7 includes a valve 7A and a flow rate regulator 7B, and continuously supplies a predetermined flow rate of carrier gas to the electrolytic cell. The liquid continuously supplied to the electrolytic cell at a constant flow rate undergoes electrolysis, and the generated hydride gas is continuously transferred to the gas-liquid separator 8 by a carrier gas. The gas-liquid separator 8 includes an overflow tank 8A, a condenser 8B provided on an air supply line led upward from its top lid, and a desiccant column 8C.
It is equipped with The liquid separated in the overflow tank 8A overflows and is discharged 12, and the separated gas is further dehydrated and dried by the condenser 8B and desiccant column 8C, and then introduced to the detection device 9. As the desiccant, calcium chloride, magnesium perchlorate, etc. are preferred. In this example, a flame photometric analyzer is used as the detection device 9, which is composed of a flame photometric detector 9A, its power source 9B, a recorder 9C, and oxygen and hydrogen gas flow rate regulators 9D and 9E. ing. Here, the gas sent from the gas-liquid separator 8 is continuously subjected to measurement, and the detected value of the hydride of the element to be measured is automatically recorded on the recorder 9C. By using a calibration curve prepared in advance, the concentration of the element to be measured in the sample can be determined. The calibration curve creation mechanism 10 includes a standard solution tank 10A in which the concentration of the element to be measured is known and a metering pump 10B, and the standard solution supply line 10D is connected to the main line by a three-way socket 10C for switching the liquid flow direction. During measurement, the three-way tank is adjusted so that the sample flows through the main line 11 from the sampling device 1 to the diluting device 2, and the flow of the standard solution is stopped. When creating a calibration curve, the three-way tank 10C is adjusted so that the flow is from the standard solution tank 10A through the three-way tank 10C to the diluter 2. After the diluter, the standard solution is passed through the main line described above to detect the generated hydride. Using standard solutions with several different concentrations, or diluting one standard solution in several proportions with the diluter 2 to obtain a detected value for each concentration, and diluting the standard solution with several concentrations supplied to the electrolyzer 6. Create a calibration curve from the detected values. The calibration curve creation mechanism may be connected to the main line immediately before the electrolyzer when there is no need to dilute, purify, adjust acid concentration, or perform reduction treatment on the standard solution. If the information on the calibration curve is stored in advance in a calculation device built into the recorder 9C, and the calculation device is made to perform comparison calibration between the detected value of the measured hydride and the calibration curve, the recorder 9C will be able to calculate the hydride concentration. can be obtained directly. The above device can be easily designed and manufactured by a person skilled in the art using commercially available parts based on the above information. The device assembled by the inventors was housed in a space measuring 40 cm wide x 50 cm high x 40 cm deep, excluding the detection device. According to the method and apparatus of the present invention, arsenic, antimony, selenium, etc. in a liquid to be measured can be measured continuously and in a very short time from sample collection, and highly accurate measurement values can be obtained. Further, the device of the present invention can withstand continuous operation for a long period of time, has high stability, is easy to maintain and manage, and can easily be made to be highly labor-saving. It also has the economical advantage of being able to be performed with less required expense. As described above, the method and apparatus of the present invention are extremely useful for tracking and constantly monitoring changes over time in the amounts of arsenic, antimony, selenium, etc. in a liquid. When arsenic hydride is produced by an electrolytic method, the following experiment was conducted to investigate the relationship between the electrolytic current and the generation rate of arsenic hydride, and the relationship between the arsenic concentration in the solution and the amount of arsenic hydride generated. Γ Experiment - Rate and amount of arsenic hydride generated by electrolysis Electrolyze a standard arsenic solution using the electrolyzer shown in Figures 1 and 2 to determine the amount and rate of arsenic hydride generated. Ta. The conditions for electrolysis were as follows. Cell capacity 6.5cm Area of ³ platinum electrodes 4.0cm Distance between ^two electrodes 0.7cm Electrolysis current 0.5~3A Arsenic concentration in standard solution 0.1~10μg/ml (Arsenic is contained as arsenite ion, but converted to elemental arsenic. Sulfuric acid concentration of standard solution 1.0N Standard solution supply flow rate 5ml/min Carrier gas (N ₂ ) supply flow rate 200ml/min Electrolysis was performed for 60 minutes under the above conditions, and the generated arsenic hydride was exposed to powder solution (5%). absorb, decompose,
After performing the concentration operation, the amount of arsenic is measured by atomic absorption spectrometry, and the amount of arsenic generated as arsenic hydride,
The incidence rate was calculated. The amount and rate of generation were calculated as values converted to elemental arsenic as follows. Amount generated (μg/ml) = Detected amount of arsenic as a single substance (μg/ml)
g)/Flow rate of solution (ml/min) x Electrolysis time (min) Generation rate (%) = Amount generated (μg/ml) x 100/Arsenic concentration in solution (μg/ml) The measurement results are shown in Table 1. FIG. 4 shows the relationship between the electrolytic current and the arsenic hydride generation rate, and FIG. 5 shows the relationship between the arsenic concentration in the solution and the amount of arsenic hydride generated.

[Table] As can be seen from the above experimental results, the generation rate of arsenic hydride is directly proportional to the electrolytic current, and shows a constant value with respect to the arsenic concentration in the solution. Therefore, if the electrolytic current is constant, the amount of arsenic hydride generated is:
Directly proportional to arsenic concentration in solution. This shows that the method of the present invention is highly reliable as a method for measuring arsenic in liquid. It was also confirmed that the amount of hydrides generated was proportional to the concentration in the solution for antimony and selenium. Example 1 Using the apparatus shown in Figure 3, two types of mock sample solutions (A , B) was prepared and continuously measured for 24 hours. The content of each chemical species in the mock sample solution (value converted to a single substance) is as follows.

[Table] Sample A and Sample B, each housed in a separate tank, were sampled alternately every 2 hours using sample collection device 1 and subjected to measurement. The sample liquid was sampled at a rate of 1/min, passed through a filter 1B, and sent to a diluter 2 via an overflow tank 1C at a flow rate of 0.4 ml/min. In diluter 2, pure water is mixed and diluted 250 times, and the diluted solution is passed to purifier 3 at a flow rate of 2.5 ml per minute.
In purifier 3, which was sent to
was passed through a column 3A filled with . In the apparatus 4, 2.5 ml of sulfuric acid was supplied per minute from the sulfuric acid tank 4A storing 2N sulfuric acid, and the sulfuric acid was sent to the reducing apparatus 5 at a flow rate of 5 ml per minute. In the reducing device 5, a reducing agent is supplied at a rate of 1 ml per minute from a reducing agent tank 5A storing an ascorbic acid aqueous solution with a concentration of 10%, and mixed in a mixing tank 5C.
Heat to 90°C or higher in D to react, and then heat in cooler 5E.
After cooling to room temperature (20°C), it was sent to electrolyzer 6 at a flow rate of 6 ml per minute. In the electrolyzer 6, the electrolytic current is set to 1 ampere by the constant current electrolytic power source 1B, and the electrolytic current is set to 1 ampere by the carrier gas supply device 7.
50ml of nitrogen gas was supplied. Furthermore, the electrolyzer 6
The shape ^of the electrolytic cell installed in
cm platinum electrodes were placed opposite each other at a distance of 0.7 cm. The gaseous product in the electrolytic cell is sent to the gas-liquid separator 8 together with the nitrogen gas and the electrolyzed liquid to separate the gas from the electrolyzed liquid, and then passed through a condenser 8B and calcium chloride pipe 8C through cold water at 5°C. After dehydration and drying, the sample was sent to a flame photometer 9, and the luminescence at a wavelength of 235 nm was measured to continuously measure arsenic. FIG. 6 shows the recording results of the changes in the above measured values over time. As shown in Figure 6, the response speed in response to concentration fluctuations caused by switching between sample A and sample B is sufficiently fast, and the fluctuations over a 24-hour period, including base and span fluctuations, are only 10% or less. It was also confirmed that the stability was sufficient. After continuous measurement for 24 hours, slight contamination was observed on the platinum electrode surface of electrolytic cell 6A and the burner section of the flame photometer, and regular maintenance inspections include cleaning of the contaminated sections, zero adjustment of the measuring equipment, It was confirmed that stable continuous measurement over a longer period of time is possible by adjusting the span and replacing and replenishing reagents. Furthermore, in this example, it took only about 15 minutes from sample collection to obtaining the detection results on the recorder.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an electrolysis device used in the analysis method of the present invention, and FIG. 2 is an elevational view of the same device.
FIG. 3 is a conceptual diagram representing the apparatus used to carry out the analytical method of the present invention. FIG. 4 is a diagram showing the relationship between electrolytic current and arsenic hydride generation rate when an arsenic-containing aqueous solution is subjected to electrolysis. FIG. 5 is a diagram showing the relationship between the arsenic concentration in the solution and the amount of arsenic hydride generated for each electrolytic current used. 6th
The figure is a diagram showing a time-measurement curve obtained when arsenic was measured in two types of samples every two hours using the apparatus of FIG. 3. 11... Container, 13... Test liquid introduction tube, 15...
...Gas liquid discharge pipe, 20...Carrier gas introduction pipe, 2
1, 22... Electrode, 1... Sample collection device, 2...
Dilution device, 3... Purification device, 4... Acid concentration adjustment device, 5... Reduction device, 6... Electrolysis device, 7...
...carrier gas supply device, 8...gas-liquid separation device,
9...Detection device.

Claims (1)

[Scope of Claims] 1. A continuous measurement method for an element in which a gaseous hydride of the element is generated when an aqueous solution of a chemical species containing the element is electrolyzed, the method comprising: continuously supplying a sample solution to an electrolyzer; and continuously guiding the gas generated in the electrolyzer together with a carrier gas to a detection device, and continuously measuring the hydride of the element contained in the gas. continuous measurement method. 2. A continuous measuring device for an element that generates a gaseous hydride of the element when an aqueous solution of a chemical species containing the element is electrolyzed, comprising a sampling device that continuously collects a sample liquid, and the collected sample. A dilution device that dilutes the solution to a concentration appropriate for electrolysis, a purification device that removes substances that interfere with electrolysis contained in the collected sample solution, and an acid concentration that adjusts the collected sample solution to the appropriate concentration for electrolysis. A reduction device that performs reduction treatment on the collected sample liquid; A sample liquid that has passed through the above devices is continuously supplied, and the sample is electrolyzed to remove the elements. An electrolyzer equipped with an electrolytic cell that generates hydrides, and a carrier gas supply device that continuously supplies a carrier gas to the electrolytic cell and continuously discharges the gas generated in the electrolytic cell from the electrolytic cell together with an electrolyzed solution. , a gas-liquid separator that separates the electrolyzed liquid and gas discharged from the electrolytic cell; and a detection device that continuously measures the hydride contained in the gas separated from the gas and liquid. Continuous measuring device for specific elements. 3. The device according to claim 2,
The device is equipped with a mechanism for creating a calibration curve that can supply a standard solution with a known concentration of the element to the electrolyzer in place of the sample solution.