JPS61215950A - Automatic colorimetric analysis - Google Patents

Abstract

PURPOSE:To make possible exact analysis with high reliability and to lessen manpower by automation by sampling a specified amt. of liquid to be examined at every specified time, introducing the sample liquid together with a specified amt. of coloring agent and other buffer chemicals, etc. into a colorimetric device and analyzing automatically the samples. CONSTITUTION:The colorimetric device forms the liquid circulation route from a mixing vessel 9 through a filter 21, a gas-liquid separating vessel 22 and a colorimetric vessel 23 to the vessel 9. A microcomputer 30 controls the device so as to sample the specified amt. of the liquid to be examined at every specified time and to introduce the sampled liquid together with the specified amt. of the coloring agent and the other buffer chemicals, etc. into the colorimetric device. The sampled liquid is circulated for the specified time in the colorimetric device and is thereby stabilized. The liquid is then decolored and is automatically analyzed by a colorimeter 26. The liquid is discharged upon ending of the analysis and after the colorimetric device is cleaned for the specified time, the specified amt. of the liquid to be measured is again sampled and the measurement is repeated. The colorimetrically measured value is digitized and displayed during this time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for automatically colorimetrically analyzing components in a test liquid containing components that change over time.

(Prior art) Conventionally, when the content date of a trace component contained in a continuously flowing liquid changes over time, the sample is collected and subjected to colorimetric analysis to examine the state of the change over time. There were various problems.

For example, when automatically measuring trace components on the order of 1 ll) B, if the line through which the test liquid passes is not thoroughly cleaned, the analytical values may be extremely unreliable due to the influence of residual liquid from the previous analysis. become.

In addition, the colorimetric analysis of the sample solution, mixing it with a coloring agent, etc., and the coloring contact liquid, and the above-mentioned washing and other operations need to be carried out quickly in order to accurately understand the changes in the test component over time. Conventionally, these processes have not been performed systematically, and each has been performed individually and manually, resulting in extremely poor efficiency and a need for improvement.

(Object of the Invention) The object of the present invention is to collect a test liquid and mix it with a drug when analyzing trace components that change over time. The object of the present invention is to provide a highly reliable and industrially useful automatic colorimetric analysis method using an apparatus in which a series of operations such as colorimetric analysis and washing are systematically assembled.

(Structure of the Invention) In other words, the present invention, when measuring the changing components of a test liquid whose components change over time using a colorimeter, samples a certain amount of the test liquid at regular intervals, and produces a certain amount of color. It is introduced into a colorimetric device together with the agent and other buffering agents, stabilized by circulation for a certain period of time in the colorimetric device, and automatically analyzed with a colorimeter after degassing. After draining the liquid and cleaning the colorimetric device for a certain period of time, a certain amount of the test liquid is sampled again and the measurement is repeated, and the colorimetric measurement value during this operation is digitized and displayed. It is a colorimetric analysis method.

To explain the method of the present invention using drawings, the unpurified liquid is placed in a tube (1).
The sample solution is purified through purification towers (2) and (2') and sent to the next step through tubes (3) and (4) as a test liquid containing trace amounts of fluctuating components. A part of it passes through the valve (5) and is led to the receiver (6) as a sampling liquid. Preferably, this liquid is continuously supplied and allowed to overflow from the pipe (7) to replace the old liquid. Sampling liquid is fixed with constant pressure valve V+, valve V2
The liquid is then guided to a mixing tank (9) by a metering pump (8). (10) is a soft water tank for cleaning, and is also a metering pump (8
) into the mixing tank (9). Further, (11) is a coloring liquid tank, (12) is a buffering chemical liquid tank, and the coloring liquid and buffering chemical liquid are each provided with a metering pump (13).

(14) leads to the mixing tank (9). These valves and pumps are controlled by a microcomputer to allow adjustment of the liquid feed to the mixing tank.

The mixing tank (9) is capable of rotating at low and high speeds by a motor (15), and is rotated at low speed to mix the liquid in the tank for an appropriate time and sufficiently color the sampling liquid. Next, this liquid is pumped into the pipe (1) by the circulation pump (18).
9) (20), filtration II (21), gas-liquid separation tank (
22), and a colorimetric tank (23), and returned to the mixing tank through tubes (24) and (25) and circulated for a predetermined period of time to stabilize the state of the liquid. ), the absorbance of the liquid at a certain wavelength is measured by a colorimeter (26). The gas-liquid separation tank (23) is installed to remove gas in the circulating fluid that causes measurement errors and stabilize the fluid. released and released. The filter (21) is effective for removing precipitates generated depending on the type of liquid, but may be omitted if no precipitates are observed.

(17) causes it to be discharged to the outside of the thread. Next, the cleaning water is pumped from the cleaning soft water tank (10) into the mixing tank (9) using the pump (8).
The same type of water is rotated at low speed to thoroughly wash the inside of the tank, and this washing water is circulated through the colorimetric device using the circulation pump (18) for washing. The cleaning water returned to the mixing tank (9) is
9) is rotated at high speed to overflow and discharged from the pipe (17). Further, the circulating fluid can also be discharged into the pipe (27) from the valve v4.

These operations will be explained in detail below.

Although the purification towers (2) and (2') are effective in removing most of salt water, hard water, etc. containing calcium, they are not always necessary depending on the type of liquid to be tested.

A plurality of sampling liquid receivers (6) may be installed, for example (6'), and these can be used as preliminary receivers to collect sampling liquid from any part of the test liquid. Switching allows analysis of several samples. As mentioned above, it is preferable to allow the sampling liquid to constantly overflow from the receivers (6) (6') so that the sample solution can be collected continuously. ) from the tube (28), and at that time, the valve (5) may be linked with a timer or the like to feed the liquid at fixed intervals. The colorimetric slide (23) is a flow cell that can automatically supply and discharge circulating fluid, and the measurement data from the spectrophotometer installed therein is converted from analog to digital by the A/D converter (29). The computer (30) stores and calculates the values, displays the results on a display, and outputs them using a printer.

In this case, one of the sampled solutions is used as a reference solution and measured in advance by another precise analysis, such as ICP or atomic absorption spectrometry, and then the absorbance is measured and compared with a blank solution to obtain a calibration line. By storing this in the microcomputer (30) and comparing the values of this reference solution and other sampled solutions, accurate measurement becomes possible.

This microcomputer (30) is a pump (8) (
13) Start/stop operations of (14) and (18), operating time, valve (5), V+, V2.

A series of operations such as opening and opening of V3 and measuring the time, starting and stopping the motor (15) that rotates the mixing W (9), switching the speed of high speed rotation and low speed rotation, and measuring the time are performed by a program. The sampling amount and time of the test solution are determined, and the amount and time of addition of the coloring agent and buffering agent, the circulation time of the colorimetric device, the rotation time of the mixing tank, the inlet of the washing water, and the washing time are determined. It is possible to standardize time, etc.

(Effects of the Invention) According to the method of the present invention, sampling of the test liquid from the flow path, addition of coloring solution, buffer solution, etc., mixing and circulation of these in the colorimetric device, colorimetric measurement, device cleaning with washing water, etc. By automating a series of repeated operations using a microcomputer, etc., labor can be saved and the operations can be performed rationally. Furthermore, since the colorimetric measurement values are digitized and input into a computer and displayed, it is possible to easily know the fluctuations in trace components in the test liquid. Circulation in the colorimetric device of the present invention is effective for stabilizing the liquid, and in particular, if solids are present in the test liquid, they can be removed by providing a filter during the circulation process. In addition, if the mixing tank is designed to be able to rotate, cleaning operations and mixing of chemical solutions can be carried out, and since the liquid extraction pump is not directly connected to the mixing tank, there is no possibility that the sampling liquid will remain in the tank or piping. Accurate analysis can be performed without affecting subsequent measurements.

EXAMPLE Calcium ion <ca++>m degrees in saturated salt water was measured using the automatic analyzer shown in FIG.

First, the following operation is performed to calculate the analysis span (conversion coefficient). Plasma emission analysis result Ca ++195
A saturated salt solution containing ppb was placed in a mixing tank, a coloring solution and a buffer solution were added thereto, and the mixture was circulated through the colorimeter shown in FIG. 1 for stabilization, and then the absorbance was measured and a value of 0.469 was obtained. After discharging this,
The same salt water was sent to a mixing tank and EDTA, a reagent that completely concealed Ca + 10, was added thereto to prepare a blank solution for Ca 10+.

This liquid was circulated through a colorimeter in the same manner as above, and the absorbance was measured to be 0.304. The coefficient to calculate +1 degree in Ca from these two absorbances is 195x 1/0.469-0.304=
Microcomputer as 1.182x 103 (
30).

1) Measurement In the soda electrolysis process, the saturated salt water sent to the electrolytic cell is passed through the chelate resin-filled purification tower (1), where most of the Ca ++
, M(1") was removed from the salt water as the test solution.

A volumetric capacity of 11 receivers (6) for a portion of the brine at the outlet of the purification tower
It is constantly overflowed at a flow rate of 542/hr to keep the receiver always filled with fresh brine. The salt water in this receiver is pumped with a metering pump (8) at a rate of 1001/sin.
into the mixing tank (9) for a minute. The above operations and the following operations described below are all automatically controlled by a microcomputer (30). Next, the color developing solution from the color developing solution tank (11) is mixed with the metering pump (13), and the buffer solution (alkali hydroxide) is mixed with the metering pump (14) from the buffer solution tank (12) at a rate of 201/inch. This mixing tank (9) is rotated at low speed (approximately 300 rpm) for 5 minutes.
) Stir thoroughly to develop color. The colored liquid is circulated through the gas-liquid separation tank (22) and the colorimetric tank (26) for 3 minutes using the circulation pump (18) to sufficiently stabilize the liquid in the colorimetric tank, and then the circulation pump (18) is turned on. Stop. Colorimeter (2
6), the absorbance is measured and the value is defined as A. Next, the mixing tank (9) is rotated at high speed (approximately 1200 rpm).
Drain the liquid in the tank.

Next, the salt water in the receiver (6) is again sent to the same mixing tank (9) by the metering pump (8).

Thereafter, an amount of reagent EDTA to completely hide Ca++ is pumped from a storage tank (not shown) to a mixing tank (9), and then a colorimetric solution and a buffer are added.

The mixing of these multiple liquids and the circulation operation of the colorimetric device are carried out in exactly the same manner as described above, and the absorbance is measured and the value is set to 8.

From the values of A and B and the coefficients, the concentration of Ca in the salt water becomes C-(A-B)
It is recorded by the printer and displayed on the display.

11) The cleaning mixing tank (9) is rotated at high speed to drain the measured salt water, and then the metering pump (8) is used to drain the salt water from the cleaning soft water tank (10).
0cc of water is sent to the mixing tank, and the tank is rotated at low speed for 2 minutes to clean the inside of the tank, and then rotated at high speed to drain the water. Next, water is again sent from the cleaning soft water tank to the mixing tank and circulated within the colorimetric device for 2 minutes using the circulation pump (18). After washing, water is drained from the mixing tank in the same manner.

The measurement and washing operations described above in 1) 11> were repeated under computer control, and the Ca++ concentration was automatically measured at regular intervals. The results are shown in FIG.

As is clear from Figure 2, the chelate resin-filled purification tower (
1) While there is still sufficient exchange capacity for Ca→ contained in the brine, the CaH1! Although the Ca++ concentration is showing a sufficiently low value, a state in which the Ca++ concentration rapidly increases when the capacity decreases is often detected.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing an embodiment of the method of the present invention, and FIG. 2 is a graph showing changes in calcium ion concentration over time in Examples. <6) (6')... Sampling liquid receiver. (9)...Mixing tank, (10)...Soft water tank for cleaning. (11)...Coloring solution tank, (12)...Buffer solution tank. (18)... Circulation pump, (22)... Gas-liquid separation tank. (23)...Colorimetric tank, (30)...Microcomputer-

Claims (5)

[Claims] (1) When using a colorimeter to measure the changing components of a test liquid whose components change over time, a certain amount of the test liquid is sampled at regular intervals, and a certain amount of coloring agent and other buffers are added to the test liquid. It is introduced into a colorimeter along with chemicals, stabilized by being circulated in the colorimeter for a certain period of time, and then automatically analyzed by a colorimeter after degassing.When the analysis is completed, the liquid is drained and kept for a certain period of time. An automatic colorimetric analysis method characterized in that after cleaning the colorimetric device, a certain amount of the test liquid is sampled again and the measurement is repeated, and the colorimetric measurement values during this operation are digitized and displayed. (2) The method according to claim 1, wherein the colorimetric device has a liquid circulation path from the mixing tank, through the gas-liquid separation tank and the colorimetric tank, and back to the mixing tank. (3) The method according to claim 2, wherein a filter is provided in the liquid circulation path between the mixing tank and the gas-liquid separation tank. (4) Claim 2, wherein the mixing tank is a tank that can rotate in at least two speeds, low speed and high speed, and is provided with a pump that pumps up the liquid in the tank from the upper part and guides it to the liquid circulation path. the method of. (5) The method according to claim 1, wherein the sampling is performed while continuously supplying the test liquid to the sample receiving tank and overflowing the excess liquid.