KR20020036929A - Method for titration and reaction rate determination using light sensor and instrument for the same - Google Patents

Abstract

PURPOSE: A method and apparatus is provided to minimize loss of reagent and material by using the small amount of reagent, while achieving improved accuracy and convenience in experiment. CONSTITUTION: A method is characterized in that neutralization reaction, oxidation-reduction reaction or response speed is measured by sensing the change of color caused due to the chemical change between reagent and sample by using an optical sensor. An apparatus is characterized in that a neutralization titration is performed by using an optical sensor for sensing the change of color caused due to the chemical change between reagent and sample. The apparatus includes an optical sensor adjustor for adjusting the voltage obtain from an optical sensor; the optical sensor and a light source connected to the optical sensor adjustor; a transparent tube interposed between the optical sensor and light source; a pipe for transferring a reagent to the transparent tube; a buret connected to the pipe; a solenoid valve for controlling cock of the buret; a clock connected to the optical sensor adjustor so as to count the reaction time; and a titration container where the optical sensor, light source and buret are installed.

Description

Method for measuring neutralization reaction and reaction rate using optical sensor and its device {Method for titration and reaction rate determination using light sensor and instrument for the same}

The present invention relates to a neutralization reaction and reaction rate measuring apparatus using an optical sensor, and more particularly, it can be used for titration or reaction rate measurement of the process of color development in the absence of color or color change in the colorless state. An experimental device designed to be used.

In the process of learning science, experiments are essential, but especially in chemistry experiments, many students are too annoying and inconvenient. In addition, if a large error occurs in the result of the same experiment in the curriculum, there is a problem in that it is difficult to continuously repeat the experiment.

Titration, often used in chemistry experiments, refers to the process of measuring the amount of known reagent required to react with an unknown sample, in which a titration reagent is added in small portions to the analyte until the reaction is complete. From this amount, determine the concentration of the analyte in the unknown sample. The most common method is to add the titrant via the burette, and the titrant added slowly must react with the analyte completely and rapidly until the analyte is exhausted. Determining when an analyte is consumed involves measuring the rapid change in current or voltage between a pair of electrodes in the analyte, by monitoring the color change of the indicator, or by measuring the absorbance of the species involved in the reaction.

This titration, which involves the reaction between acid and base, is most widely used in chemical analysis, and the titration apparatus frequently used in scientific experiments is mainly manufactured using electric conductivity and pH meter, and the reaction rate using color change In most cases, the stopwatch is used. However, these are expensive and difficult to titrate in small amounts.

On the other hand, in recent years, devices related to light quantity or advanced color recognition devices are rapidly developing, and if the experimental apparatus is manufactured using them, more accurate and simple experiments can be performed.

The inventors of the present invention conducted a test to manufacture a simple and convenient neutralization reaction (titration) and reaction rate measuring device using an optical sensor. As a result, it was confirmed that the present invention is very effective for measuring acid, base neutralization reaction, redox reaction and reaction rate, and the surrounding environment. However, the present invention was completed by developing a cheap measuring device that can improve the general method of experimentation and the general method of slightly different results depending on the time of day.

Accordingly, it is an object of the present invention to provide a measuring method using a light sensor and a measuring apparatus which can perform the neutralization reaction and reaction rate measurement experiment very simply and conveniently.

The object of the present invention is to design a circuit that can measure the sensitivity of several light-receiving elements by using a spectrophotometer to investigate the wavelength of the maximum absorbance using a spectrophotometer and using commercially available green and red LED infrared elements as a light source. After the design, the measurement device was made, and the above-mentioned devices were used to determine whether the acid, base titration and ascorbic acid, iodine-starch reaction rate and randol reaction time were actually applicable. This was achieved by examining very accurate and effective.

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

1 is a schematic diagram showing the overall manufacturing process of the measuring device of the present invention.

2 is a diagram showing an electronic circuit of the measuring device of the present invention.

Figure 3 is a diagram showing a titration vessel of the measuring device of the present invention.

4 is a diagram showing the overall configuration of the measuring device of the present invention.

It is a figure which shows the wavelength and absorbance of the discoloration solution by a phenolphthalein (a) and a starch indicator (b).

6 is a diagram showing a titration result of a general method (a) and a titration method (b) using the measuring apparatus of the present invention.

7 is a diagram comparing the results of the general method and the method using the measuring device of the present invention when the acid is titrated with 0.0525M NaOH.

8 is a diagram comparing the results of the general method and the method using the measuring device of the present invention when the acid is titrated with 0.0049M NaOH.

9 is a view comparing the results of the general method and the method using the measuring device of the present invention when the acetic acid concentration of commercially available vinegar is titrated.

10 is a diagram comparing the results of the general method and the method using the measuring device of the present invention when the concentration of ascorbic acid (vitamin C) in a commercially available fruit beverage is titrated.

11 is a graph showing the results of the reaction rate according to the concentration change of NaHSO ₃ .

12 is a graph showing the reaction rate results according to the change in concentration of KIO ₃ .

13 is a graph showing the reaction rate results (colorless-orange) according to the concentration change of NaHSO ₃ .

14 is a graph showing the reaction rate results (orange-colorless) according to the concentration change of NaHSO ₃ .

15 is a graph showing the reaction rate result (colorless-orange) according to the change in concentration of KIO ₃ .

16 is a graph showing the reaction rate result (orange-colorless) according to the concentration change of KIO ₃ .

As a result of the titration experiment using the measuring device of the present invention, the combination of the green LED and IMT708810NPhotodiode was able to completely titrate the acid-base in the dilute solution than the concentration of 10-3M, and the starch reagent was used in the combination of the red LED and the phototransistor Iodine titration and reaction rate could be measured, and it was determined that the present measuring device could be applied when automating component analysis such as acetic acid in vinegar or ascorbic acid (vitamin C) in fruit drinks. In addition, since the Randolt reaction time that changes colorless-orange-colorless was measured by the present invention interlocking stopwatch, using an optical device such as the measuring device of the present invention not only can produce a titration device at a low cost Since the experiment can be carried out with a small amount of sample and raw material, it was determined that the development of the present invention titration and reaction rate measuring device would be a more excellent measuring equipment.

The titration device of the present invention, characterized in that the titration of the color change of the neutralization reaction using an optical sensor includes an optical sensor regulator capable of adjusting the voltage obtained from the optical sensor; An optical sensor (light receiving element) and a light source connected to the optical sensor regulator; A transparent test tube installed between the optical sensor and the light source; A tube capable of flowing an acid or base connected to the transparent test tube; A burette connected to the tube; A solenoid valve for controlling the cock of the burette containing the reaction liquid; An interlocked stopwatch connected to an optical sensor regulator for measuring reaction time; And an appropriate container for dark conditions in which the optical sensor, the light source, and the glass tube are installed.

Reaction rate measuring device according to the present invention, characterized in that for measuring the reaction rate using a color change detection optical sensor; An optical sensor (light receiving element) and a light source connected to the optical sensor regulator; A transparent test tube installed between the optical sensor and the light source; A cockled test tube for sending a reaction solution to the transparent test tube; It is characterized in that it comprises a micro switch unit which is installed in the cocked test tube and the solution flows down and can be turned on and connected to the micro switch unit and connected to the optical sensor regulator.

The circuit design and operation principle of the measuring device of the present invention will be described with reference to the drawings.

Figure 2 is a diagram showing the electronic circuit of the measuring device of the present invention, the light generated by the LED1 in Figure 2 (c) reaches the optical sensor through the sample. The light sensor's resistance changes according to the light's intensity.When the light from the light source reaches the sensor as it is, the resistance is small and the current flowing through the circuit becomes large.In contrast, when light is absorbed due to the color development of the solution in the application vessel, As the resistance increases, the intensity of the current flowing decreases (voltage decrease of V2), and the difference between the voltage set by the variable resistor Rx (sensitivity adjustment) and the voltage of V2 increases in FIG. IC1 displays the voltage set by the variable resistor Rx to the DVM. It is used for amplification to compensate for the voltage lost in the DVM. The voltage difference is amplified by IC2. TR1 can be started with the amplified voltage, but to have a sensitive sensitivity to color development, the reference voltage of IC4 is set using a 10kΩ variable resistor connected from IC3. To check the set voltage, I used a toggle switch to connect to the DVM. The output voltage of IC4 turns on TR1 and the relay operates as current flows from the collector to the emitter. The relay controls the solenoid to stop the fluid flowing through the burette. The present inventors used the optical coupler to obtain a signal at the collector side of TR1 to measure the reaction rate and control the stopwatch (FIG. 2 (f)). The interlocked stopwatch uses the signal of an autonics timer (FX6Y-I) as it is. And drive stage was added to run FMD.

3 is a diagram showing the titration vessel of the present invention used for the neutralization reaction titration. The titration vessel was made by processing black polymer to block external light. Figure 3 (A) is to be able to put the test tube in the center (when the test tube is inserted, the spacing was produced about 0.2mm). The bottom facing hole is where the light source on one side and the light-receiving element are inserted on the other side. The present inventors selected the positions of these holes downward so as to prevent the phenomenon that the ON-OFF of the relay is repeated (chatting phenomenon) when approaching the end point in the titration as much as possible. When the test tube enters, the thickness of the lower part is made thin so that the magnetic stir bar can enter. Lid (B) has a hole (2.2 mm in diameter) in the center for 2 mm PVC pipe to pass through. This is where the solution flows from the burette through the solenoid valve (FIG. 4) into the test tube. The socket (C) of the optical device is manufactured to fit in the lower hole of Figure 3 (A) has a hole in the center.

Figure 4 is a diagram showing the overall configuration of the reaction rate measuring apparatus of the present invention. The measuring device includes a reaction vessel, a sensing section, and a micro-switch with a stopcock start tube and stopwatch designed to allow the reactant to flow down easily.

Hereinafter, the present invention will be described through examples. However, the following examples are only for the purpose of illustrating the present invention and the scope of the present invention is not limited to the following examples.

Example 1 Selection Experiment of Optical Device

Spectrophotometer (Spectronic 20: Milton Roy Company) was used to test the maximum absorbance and wavelength relationship of the solution developed by the indicator of phenolphthalein and green film. Green LED (565nm), Red LED (635nm), Infrared Device as Light Source, CDS, Photodiode (IMT T0810N, SP-1KL), Phototransistor (9015 F544) as Photodetector It was tested whether it was applicable to acid-base titration and iodine titration. Insert the light source on one side and the light-receiving element on the other in the two opposite holes of the titration vessel, and put the transparent solution of the acid solution and the solution developed by the phenolphthalein indicator into the titration vessel. And the operation state was tested using the dark blue solution shown by the iodine-starch reaction.

As shown in Tables 1 and 2, the maximum absorbance of the red solution discolored by the phenolphthalein indicator was at 550 nm and the maximum absorbance of the dark blue solution discolored by the starch reagent was at 570 nm. (Figures 5a and b). It was judged that the optical element emitting exactly this area is effective for titration. Infrared devices easily passed through the solution developed by phenolphthalein and starch reagent, so that the resistance change of the light-receiving device was not suitable for the proper device. However, in the change of orange color indicated by the mercuric chloride indicator in the reaction rate measurement, the infrared emitting device is shown to be good (Table 3) .In the titration or reaction rate measurement, the optical device can be replaced by emitting light of the required wavelength according to the selection. More effective.

Example 2 titration of acid, base

In this example, a phenolphthalein solution (1%), NaOH base solution standardized with Potassium biphthalate (KHP) dried at 100 ° C, 0.05M, 0.005M NaOH, 0.1M HCL stock solution, and KHP solution were prepared, and the following experiment was performed. It was.

(1) Standardization of 0.05M, 0.004M NaOH: Since the monovalent acid KHP and NaOH solution react at a molar ratio of 1: 1, a 25 mL burette is filled with a NaOH base solution and a 200 mL triangular flask KHP (5 × 10 ^-2 M). 100 mL was added using a syringe (10 mL) and two drops of phenolphthalein indicators were added. Put the stirrer bar in the Erlenmeyer flask and rotate slowly to avoid ripples. The initial scale of the burette was recorded and titrated as the end point when the faint red color remained for about 30 seconds. The experiment was repeated five times to determine the concentration of the base solution as the average value. The 0.004M NaOH solution was normalized to 0.003M KHP using the same method as above. In order to accurately determine the concentration of acid, the two bases (NaOH) A and B were standardized by KHP. As a result, NaOH (A) concentration was 0.0525M and NaOH (B) was 0.0049M (Table 4, Table 5). ).

(2) determination of acid concentration

Approximately 10 mL (A) of HCl was added to a 200 mL triangle flask and three drops of phenolphthalein indicator were added and titrated with a NaOH solution standardized in the above experiment in a burette. The end point was when the faint red color stayed longer than 30 seconds. The same solution was placed in a titration vessel and three drops of phenolphthalein were added and placed in a dark box. A standard NaOH solution was placed in a burette connected to the solenoid and a PVC tube connected to the solenoid's NO valve was inserted through the hole in the dark box. The switch of the measuring device of the present invention was turned on and it was checked whether the front LED was turned off. The voltage was adjusted to 4.56V by turning the sensitivity volume to the right for maximum sensitivity. The initial scale of the burette was recorded, the cock of the burette was opened to allow the solution of the burette to descend, and the flow rate was not fast. When the end point is reached, the LED on the front of the titration measuring device lights up to stop the titration automatically.In the same way, the titration method for B, C, and D solutions is compared with the results using the titration device of the present invention. It was. And acetic acid was quantified by diluting 1000 times the commercial apples, candles, and vinegar. For neutralization reaction, green LED was used as light source and Photodiode (IMT-7801N) as light receiving device.

When the same acid solution was titrated with base solution of different concentration in the general method, the error was the largest at 1.36 × 10 ^-3 M concentration in the D solution having the highest acidity. The concentration of acid was lower when using a thicker base solution than when using a dilute base solution. The acid solution with the largest error was B and the error value was 7.35 × 10 ⁻⁴ M (FIGS. 6A, 6B).

Titration results using standardized 0.0525M NaOH (A) and titration results using standardized 0.0049M NaOH (B) are shown in Tables 6 and 7, respectively.

When titrating with a concentrated base solution (0.0525M), the difference between the general method and the result obtained by using the titration measuring device of the present invention (FIG. 7) is better than the result when titrating with a dilute base solution (0.0049M NaOH) (FIG. 8). The error was severe. In the case of titration with 0.0049M NaOH base solution, the results obtained by using the titration apparatus of the present invention and the general method showed almost agreement.

To determine the concentration of acetic acid in commercially available vinegar, the titration results using a standardized 0.0049M NaOH is shown in Table 8.

Among the commercially available vinegars, brewed vinegar was found to have the highest amount of acetic acid. Apple cider vinegar showed the largest difference in the results of the general method and the method using the titration measuring device of the present invention (Fig. 9). The error was 5 x 10 ^-5 M.

Example 3 Iodine Crystal of Ascorbic Acid

A starch solution (0.2 g / 50 mL water), 0.003 L L-ascorbic acid, commercially available D company's yo-yo, a refreshing morning (100% orange), a refreshing morning (100% grape), and an iodine solution were prepared.

(1) Determination of concentration of iodine solution: First, 10 mL of 0.003 M ascorbic acid was added to a 200 mL triangle flask, 1 mL of starch solution was added, and the iodine solution prepared in the burette was added and titrated. When the dark blue color appeared as an end point, the concentration of the iodine solution was determined (Table 9).

In order to accurately determine the concentration of vitamin C in fruit drinks, pure ascorbic acid was detitrated to determine the concentration of iodine. The concentration of iodine solution was found to be 1.6 × 10 ⁻³ .

(2) Determination of Ascorbic Acid Concentration in Commercial Drinks

10 mL of diluted commercial drink water was placed in an Erlenmeyer flask and 15 drops of starch solution were added. Iodine solution was added to the burette and the initial scale was read. It was made into the end point, when stirring with stirring with a stirrer and black blue appeared. The amount of iodine solution used was calculated and the amount of vitamin C contained in 10 mL of the diluted beverage was calculated to calculate the amount contained in the stock solution. The experiment was conducted under the same conditions using the titration measuring device of the present invention. A red LED was used as a light source to match the maximum absorbance of the dark blue solution with the iodine-starch reaction and the emission wavelength of the LED. A 9015F 544 phototransistor was used as the light receiving element. 10 mL of commercially available beverages were placed in a titration vessel and 15 drops of starch solution were added. The burette was filled with the iodine solution used in the previous experiment and the scale was recorded. The electronic circuit was adjusted as in acid-base titration. The cock of the burette was opened and titration was started. When the end point is reached, the solution flowing through the solenoid valve stops and the volume applied at that time was calculated (Table 10).

The maximum error was 1.6 10-3M concentration between the general method and the method using the titrator of the present invention, the difference in iodine solution was found to be added 0.1mL in 100% orange, 100% grape (Fig. 10). Yo-yo, orange 100%, grape 100% in order from dark to dark. It was judged that the cause of the error was found only when the liquid beverage had the liquidity, absorbance and precise volume measurement.

Example 4 Reaction Rate Measurement

0.05M NaHSO ₃ , 0.25M NaHSO ₃ , 1% starch solution, 0.05M KIO ₃ , 0.1M KIO ₃ , 0.01M HgCl ₂ solution was prepared and the following experiment was performed.

(1) Kinetics of NaHSO ₃ and KIO ₃ Concentration

^{_{IO 3 - (aq) + 3HSO}} 3 - (aq) → I - (aq) + 3SO4 2- (aq) + 3H + (aq)

^{_{IO 3 - (aq) + 8I}} - (aq) + 6H + (aq) → 2I 3 - (aq) + 3H 2 O (aq)

^{_{2I 3 - (aq) + starch}} blue → starch-I 5 - complex + I - (aq)

Three 50 mL burettes were fixed to the clamps connected to the stand, and each burette was labeled with NaHSO ₃ , KIO ₃ and distilled water. And 2 to prepare a single measuring cylinder (50mL) similarly attached a name tag (NaHSO _3, KIO _3). Each burette was filled with a solution for the label and scaled. A reaction rate measuring device was installed, the power supply was turned on to the detection device and the super stopwatch, and the micro switch under the cocked test tube was turned ON to check the operation state of the stopwatch. If it operates normally, leave all the switches in the OFF position. Iodine starch reaction was performed using a red LED as a light source and a 9015F 544 phototransistor as a light receiving sensor. The titration vessel used for acid-base titration was still used. The measuring cylinder is NaHSO ₃ was named take 0.05M NaHSO ₃ 2mL) and distilled water (8mL from the burette. The measuring cylinder is named KIO ₃ was placed to prepare receiving 0.05M KIO ₃ 10mL from the burette. The test tube was poured with a measuring cylinder solution labeled NaHSO ₃ and a spin bar was added thereto. The test tube was stirred through the top hole of the titration vessel. The stirrer was started and stirred at a suitable speed. A test cylinder with a cock (fixed to the top of the stand) was poured after confirming that the measuring cylinder solution with the KIO3 label was left closed. The PVC tube connected to the lower part of the test tube with a cock (glass tube) was lowered down to allow the test tube to be inserted into a titration container. This allowed the light to flow down the test tube wall in both the passing and 90 degree directions. This is because if the solution comes down to the center, the chattering of the sensor may cause the error. The detection power was turned on and the red LED on the panel was turned off. (In this experiment, we tested at 4.71V. This voltage must be constant each time.) Toggle the left side of the Super Stopwatch to the middle so that 00 minutes 00 seconds 0 appears. The cock of the test tube was rotated clockwise until the microswitch was turned on. The measurement of the stopwatch began from the moment the microswitch was turned on. (When black, the stopwatch was automatically stopped and the time was recorded. The reaction time was measured by changing the concentration of the reactants in the same manner.

The results of the measurement using the red LED as the light source and the 9015F 544 phototransistor with the light receiving sensor were shown in Tables 11 and 12 below.

The reaction rate was found to increase in proportion to the concentrations of NaHSO ₃ and KIO ₃ .

(2) Time measurement of Randol reaction showing colorless-orange-colorless change

^{_{IO 3 - (aq) + 3HSO}} 3 - (aq) → I - (aq) + 3SO 4 2- (aq) + 3H + (aq)

_{(Aq) → HgI 2 (s} ) 1 / K sp = 9.1 × 10 27 - + 2I Hg 2+ (aq)

^{_{HgI 2 (s) + I -}} (aq) → HgI 3 - (aq) K eq = 0.45

^{_{HgI 3 - (aq) + I}} - (aq) → HgI 4 2- (aq) K eq = 63

50 mL, 4 burettes were fixed to the clamp connected to the stand, and each burette was labeled with NaHSO ₃ , HgCL ₂ , KIO ₃ and distilled water. And four measuring cylinders were prepared and the name tag was attached. Each burette was filled with a solution for the label and scaled. A reaction speed test device was installed, the power supply was turned on to the detection device and the super stopwatch, and the microswitch under the cocked test tube was turned ON to check the operation state of the stopwatch. If it works normally, leave all the switches on. After confirming the name tag of the burette in a measuring cylinder with 0.25M NaHSO ₃ name tag, 18 mL was taken. And 2 mL of distilled water was added to this measuring cylinder from the burette named distilled water. In the same manner, 6 mL of 0.01 M HgCl _2, 6 mL of distilled water, 5 mL of 0.1 M KIO _{3, and} 5 mL of distilled water were placed in a measuring cylinder with each name tag. A solution of a measuring cylinder labeled with NaHSO ₃ was poured into the test tube of the reaction rate apparatus. Make sure that the test tube cock with the cock fixed to the clamp is closed and pour a solution of the measuring cylinder named KIO ₃ . At this time, there should be a test tube with a cock in the position where the microswitch below can be turned on when the cock is opened. With the cock closed, a solution of the measuring cylinder labeled HgCl ₂ was poured into the test tube below. The speed of the stirrer was set not to wave and the speed was not changed until the end of the experiment. The sensor was switched on and the voltage was checked (the set voltage of the first experiment had to be changed). In this experiment, 1.15 volts was set. At this time, the LED of the regulator was off. I then reset the dial by setting the toggle switch on the super stop to the middle. The top and bottom two stopwatches show 00 minutes 00 seconds 0. The cock of the test tube with the cock was turned so that the microswitch was turned on not too fast. The KIO ₃ solution quickly flowed into the test tube and the stopwatch started. At this time, the toggle switch on the left side of the stopwatch was placed. When the solution turns colorless, the stopwatch below stops, and the reaction time is recorded. The above procedure was repeated three times and averaged. In the same manner, the reaction time was measured by changing the concentration of the reactants.

The reaction times according to NaHSO ₃ , KIO ₃ and HgCl ₂ concentrations are shown in Tables 13, 14 and 15, respectively.

(0.1M KIO ₃ 5mL + Distilled Water 5mL, 0.25M NaHSO ₃ 10mL + Distilled Water 10mL Schedule)

Since infrared can be used to measure time while observing a color change, the time is measured by using an infrared, a transmission, or a light receiving element in a reaction in which the change occurs. The sensitivity of the SP-1KL device used in this experiment has the maximum sensitivity in the infrared region, but it is also widely visible in the visible region. Therefore, the chattering phenomenon of the manufactured device was considered to be the cause of the error. From the results of the above experiment, it was judged that it would be a great help in setting the time according to the concentration of the reactants when designing the Randol reaction. The concentrations of NaHSO3 and KIO3 in the experimental conditions affected the reaction rate of the process of changing from colorless to orange, but it was found that the concentration of KIO3 significantly affected the reaction rate of the process of changing from orange to colorless. The concentration range of the mercury chloride indicator was 0.083M-0.05M, resulting in colorless-orange-colorless change.

As described above, the optical device can be used to manufacture a neutralization reaction and reaction rate measuring device at a low cost, and can also minimize the loss of reagents and raw materials since the experiment can be performed even with a small amount of samples. The present invention is a very useful invention in the chemical and experimental instrument manufacturing industry because of the features that can be used accurately and easily.

Claims (5)

A neutralization reaction or reaction rate measuring method using an optical sensor, characterized in that for measuring the neutralization reaction, redox reaction or reaction rate by detecting the color change by the chemical change between the sample and the reaction reagent using an optical sensor. Neutralizing reaction measuring apparatus characterized in that the neutralization titration using an optical sensor that can detect the color change by the chemical change between the sample and the reaction reagent. 3. The apparatus of claim 2, wherein the measuring device comprises: an optical sensor regulator capable of adjusting a voltage obtained from the optical sensor; An optical sensor (light receiving element) and a light source connected to the optical sensor regulator; A transparent test tube installed between the optical sensor and the light source; A tube transferring a titration reagent to the transparent test tube; A burette connected to the tube; A solenoid valve controlling the cock of the burette; An interlocked stopwatch connected to an optical sensor regulator for measuring reaction time; And a titration vessel in a dark condition in which the light sensor, the light source, and the glass tube are installed. Reaction rate measuring device, characterized in that for measuring the reaction rate by using an optical sensor that can detect the color change by the chemical change between the sample and the reaction reagent. 5. The apparatus of claim 4, wherein said measuring device comprises: an optical sensor regulator; An optical sensor (light receiving element) and a light source connected to the optical sensor regulator; A transparent test tube installed between the optical sensor and the light source; A cockled test tube for sending a reaction solution to the transparent test tube; And a micro switch installed in the cocked test tube and an interlocking stopwatch connected to the micro switch and connected to an optical sensor regulator.