阅读说明：本技术 水样的高锰酸盐指数检测装置和方法 (Permanganate index detection device and method for water sample ) 是由 吴聪聪 苏龙 李佩聪 胡建坤 唐小燕 于 2021-08-16 设计创作，主要内容包括：本发明提供了水样的高锰酸盐指数检测装置和方法,所述水样的高锰酸盐指数检测装置包括反应室,所述反应室的底端具有第一进口；还包括：第一管道的一端连通所述反应室,另一端连接输送泵,所述输送泵连通气源；第二管道的一端连通所述第一管道,另一端连通第一定量泵,所述第一定量泵连接高锰酸盐容器。本发明具有水样和试剂消耗量小、检测时间短、结果准确等优点。(The invention provides a permanganate index detection device and a permanganate index detection method for a water sample, wherein the permanganate index detection device for the water sample comprises a reaction chamber, and the bottom end of the reaction chamber is provided with a first inlet; further comprising: one end of the first pipeline is communicated with the reaction chamber, the other end of the first pipeline is connected with a delivery pump, and the delivery pump is communicated with an air source; one end of the second pipeline is communicated with the first pipeline, the other end of the second pipeline is communicated with a first quantitative pump, and the first quantitative pump is connected with the permanganate container. The invention has the advantages of small water sample and reagent consumption, short detection time, accurate result and the like.)

1. The permanganate index detection device for the water sample comprises a reaction chamber, wherein a first inlet is formed in the bottom end of the reaction chamber; the permanganate index detection device of the water sample is characterized by further comprising:

one end of the first pipeline is communicated with the reaction chamber, the other end of the first pipeline is connected with a delivery pump, and the delivery pump is communicated with an air source;

the device comprises a second pipeline and a dosing pump, wherein one end of the second pipeline is communicated with the first pipeline, the other end of the second pipeline is communicated with the first dosing pump, and the first dosing pump is connected with a permanganate container.

2. The device for detecting the permanganate index of a water sample according to claim 1, wherein the reaction chamber has a second inlet, and one end of the first pipeline is communicated with the second inlet.

3. The aqueous permanganate index detection device according to claim 1, wherein the delivery pump is a peristaltic pump.

4. The detection method for the permanganate index of the water sample is characterized by comprising the following steps:

in the titration process, the conveying pump conveys gas into the reaction chamber through a first pipeline;

meanwhile, a first quantitative pump quantifies the potassium permanganate solution, sequentially penetrates through a second pipeline and the first pipeline, mixes the gas and enters the reaction chamber.

5. The method of claim 4, wherein the gas enters the reaction chamber quasi-continuously and the potassium permanganate solution enters the reaction chamber in pulses.

6. The method for detecting the permanganate index of a water sample according to claim 4, wherein the potassium permanganate solution enters the reaction chamber by the following method:

a water sample and a digestion solution enter the reaction chamber from the first inlet;

after digestion is finished, obtaining the light absorption value A of the solution in the reaction chamber_x；

Using absorbance value A_xAnd obtaining the predicted concentration C of the water sample by the first mapping relation between the water sample concentration C and the light absorption value A_{Preparation of}；

Using the predicted concentration C_{Preparation of}And obtaining a second mapping relation between the water sample concentration C and the titration end point volume V to obtain a titration end point prediction volume V_{Preparation of}；

At a first speed v₁Adding a potassium permanganate solution V into the reaction chamber₁，1<V_{Preparation of}/V₁<2；

At a first speed v₂Adding a potassium permanganate solution to the reaction chamber, v₂<v₁Until the obtained light absorption value of the solution in the reaction chamber is greater than a threshold value, so as to obtain a titration end point volume V;

and obtaining the permanganate index of the water sample by utilizing the volume V and the second mapping relation.

7. The method for detecting the permanganate index of a water sample according to claim 6, wherein the first mapping is obtained by:

sending the first standard solution and the digestion solution to the reaction chamber, and obtaining a solution light absorption value A in the reaction chamber after digestion is finished₁；

Adding a reducing agent into the reaction chamber, titrating, and obtaining a light absorption value A of the solution after each titration until the light absorption value A exceeds a threshold value to obtain a titration end point volume V₁₁；

Obtaining a light absorption value A of the second standard solution in the digestion container by using the method₂And titration end point volume V₂₂；

And obtaining a first mapping relation between the water sample concentration C and the light absorption value A and a second mapping relation between the water sample concentration C and the titration end point volume V by using the first standard solution and the second standard solution, the light absorption value and the titration end point volume.

8. The method of detecting permanganate index in a water sample according to claim 4, wherein in digestion of a water sample, the valve at the outlet of the reaction chamber and the valve at the first inlet are both closed, and a closed space is formed in the reaction chamber.

9. The method for permanganate index detection of a water sample according to claim 4 wherein the transfer pump sends air into the reaction chamber.

10. The method for detecting the permanganate index of a water sample according to claim 9, wherein the water sample, the digestion solution and the reducing agent are respectively fed into the reaction chamber by using a sequential injection platform.

Technical Field

The invention relates to water sample monitoring, in particular to a permanganate index detection device and method for a water sample.

Background

In the automatic monitoring process of surface water, drinking water and source water, permanganate index is used as an important index and is usually detected by adopting a permanganate titration method. The main contents of the permanganate titration method (GB11892-89) are as follows: adding corresponding amount of potassium permanganate and sulfuric acid into a water sample, uniformly mixing and digesting at high temperature, wherein the potassium permanganate can sufficiently oxidize reducing substances, adding excessive sodium oxalate to consume the residual potassium permanganate, finally dropwise adding the potassium permanganate, determining a reaction end point through the mutation of the color or potential value of a reaction system, and calculating the permanganate index in the water sample by using the actual titration amount of the consumed potassium permanganate. This detection method has a number of disadvantages, such as:

1. even if the quantitative pump can finish high-precision quantification in a level of less than 10 mu L, the minimum volume of liquid in a converged drop mode is dozens of mu L, so that the single titration volume of the potassium permanganate solution is large, and the consumption of samples and other reagents is large;

2. by extending the potassium permanganate solution below the liquid level, small-volume titration can be realized, but the pipeline is polluted by the sample, so that the analysis accuracy is influenced;

3. the titration time is directly proportional to the sample concentration, resulting in a longer analysis time the closer the sample concentration is to the range value.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a permanganate index detection device for a water sample.

The purpose of the invention is realized by the following technical scheme:

the permanganate index detection device for the water sample comprises a reaction chamber, wherein a first inlet is formed in the bottom end of the reaction chamber; the permanganate index detection device of the water sample further comprises:

one end of the first pipeline is communicated with the reaction chamber, the other end of the first pipeline is connected with a delivery pump, and the delivery pump is communicated with an air source;

the device comprises a second pipeline and a dosing pump, wherein one end of the second pipeline is communicated with the first pipeline, the other end of the second pipeline is communicated with the first dosing pump, and the first dosing pump is connected with a permanganate container.

The invention also provides an analysis method using the permanganate index detection device, and the analysis method is realized by the following technical scheme:

the detection method of the permanganate index of the water sample comprises the following steps:

in the titration process, the conveying pump conveys gas into the reaction chamber through a first pipeline;

meanwhile, a first quantitative pump quantifies the potassium permanganate solution, sequentially penetrates through a second pipeline and the first pipeline, mixes the gas and enters the reaction chamber.

Compared with the prior art, the invention has the beneficial effects that:

1. the water sample and reagent consumption is low;

the potassium permanganate solution and the gas are simultaneously fed into the reaction chamber by utilizing the same pipeline, so that the quantitative potassium permanganate solution is ensured to completely enter the reaction chamber, and the volume of the potassium permanganate solution titrated once is reduced, thereby reducing the dosage of a water sample and a reagent;

2. accurate quantification

The potassium permanganate solution and the gas are simultaneously sent into the reaction chamber by utilizing the same pipeline, so that the pipeline is prevented from being polluted by a sample, the accuracy of the amount of the reagent entering the reaction chamber is ensured, and the quantitative accuracy of the permanganate index is improved;

3. the detection time is short;

the potassium permanganate solution and the gas are simultaneously fed into the reaction chamber by utilizing the same pipeline, so that the titration time is reduced, and the detection time is shortened;

the dropping amount of the potassium permanganate solution is predicted and then titrated at different speeds, so that the titration time is shortened, the analysis time of high-concentration samples is shortened, and the analysis time of the samples with different concentrations is shorter than 30 min.

Drawings

The disclosure of the present invention will become more readily understood with reference to the accompanying drawings. As is readily understood by those skilled in the art: these drawings are only for illustrating the technical solutions of the present invention and are not intended to limit the scope of the present invention. In the figure:

fig. 1 is a schematic structural diagram of a permanganate index detection apparatus for a water sample according to an embodiment of the present invention.

Detailed Description

Fig. 1 and the following description depict alternative embodiments of the invention to teach those skilled in the art how to make and reproduce the invention. Some conventional aspects have been simplified or omitted for the purpose of explaining the technical solution of the present invention. Those skilled in the art will appreciate that variations or substitutions from these embodiments will be within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. Thus, the present invention is not limited to the following alternative embodiments, but is only limited by the claims and their equivalents.

Example 1:

fig. 1 shows a schematic structural diagram of a permanganate index detection apparatus according to an embodiment of the present invention, and as shown in fig. 1, the permanganate index detection apparatus includes:

a reaction chamber 11, wherein the bottom end of the reaction chamber 11 is provided with a first inlet, and the top end of the reaction chamber 11 is provided with an outlet;

one end of the first pipeline is communicated with the reaction chamber 11, the other end of the first pipeline is connected with the delivery pump 21, and the delivery pump 21 is communicated with an air source;

one end of the second pipeline is communicated with the first pipeline, the other end of the second pipeline is communicated with the first quantitative pump 31, and the first quantitative pump is connected with the permanganate container 61;

a sequential injection platform 71, such as a combination of a multi-channel selector valve and a pump, is used to feed the water sample, digestion solution and reducing agent into the reaction chamber, respectively.

In order to ensure that the sample introduction and the titration do not interfere with each other, the reaction chamber 11 further has a second inlet, and one end of the first pipeline is communicated with the second inlet.

The permanganate index detection method of the water sample provided by the embodiment of the invention comprises the following steps:

during the titration, the delivery pump 21 delivers the gas into the reaction chamber 11 through the first pipe;

meanwhile, the first quantitative pump 31 quantifies the potassium permanganate solution, and sequentially passes through the second pipeline and the first pipeline to mix the gas and enter the reaction chamber 11.

For the delivery of gas and potassium permanganate solution, the gas is furthermore fed quasi-continuously into the reaction chamber, and the potassium permanganate solution is fed in pulsed fashion into the reaction chamber.

In order to shorten the titration time, further, the potassium permanganate solution enters the reaction chamber in the following way:

a water sample and a digestion solution enter the reaction chamber from the first inlet;

after digestion is finished, obtaining the light absorption value A of the solution in the reaction chamber_x；

Using absorbance value A_xAnd obtaining the predicted concentration C of the water sample by the first mapping relation between the water sample concentration C and the light absorption value A_{Preparation of}；

Using the predicted concentration C_{Preparation of}And obtaining a second mapping relation between the water sample concentration C and the titration end point volume V to obtain a titration end point prediction volume V_{Preparation of}；

At a first speed v₁Adding a potassium permanganate solution V into the reaction chamber₁，1<V_{Preparation of}/V₁<2；

At a first speed v₂Adding a potassium permanganate solution to the reaction chamber, v₂<v₁Until the obtained light absorption value of the solution in the reaction chamber is greater than a threshold value, so as to obtain a titration end point volume V;

and obtaining the permanganate index of the water sample by utilizing the volume V and the second mapping relation.

In order to obtain an accurate mapping relationship, further, the first mapping relationship and the second mapping relationship are obtained by:

sending the first standard solution and the digestion solution to the reaction chamber, and obtaining a solution light absorption value A in the reaction chamber after digestion is finished₁；

Adding a reducing agent into the reaction chamber, titrating, and obtaining a light absorption value A of the solution after each titration until the light absorption value A exceeds a threshold value to obtain a titration end point volume V₁₁；

Obtaining a light absorption value A of the second standard solution in the digestion container by using the method₂And titration end point volume V₂₂；

And obtaining a first mapping relation between the water sample concentration C and the light absorption value A and a second mapping relation between the water sample concentration C and the titration end point volume V by using the first standard solution and the second standard solution, the light absorption value and the titration end point volume.

In order to shorten the digestion time, further, in the digestion of the water sample, the valve at the outlet of the reaction chamber and the valve at the first inlet are both closed, and a closed space is formed in the reaction chamber.

Example 2:

an application example of the permanganate index detection apparatus and method according to embodiment 1 of the present invention.

In this application example, as shown in fig. 1, a first valve 41 is installed upstream of a first inlet of the reaction chamber 11, and a second valve 42 is installed at an outlet; the conveying pump 21 adopts a peristaltic pump to convey air into the reaction chamber 11 quasi-continuously; the sequential injection platform 71 adopts a combination of a multi-channel direction selection valve and a pump, and is used for respectively feeding a water sample, a digestion solution and a reducing agent into the reaction chamber 11; one end of the first pipe is communicated with a second inlet of the reaction chamber 11, and the communication point of the second pipe and the first pipe is positioned between the second inlet and the delivery pump.

The permanganate index detection method of the water sample provided by the embodiment of the invention comprises the following steps:

in the digestion stage, a water sample and a digestion solution (passing through the first inlet) are respectively fed into the reaction chamber by using the sequential injection platform, and the first valve and the second valve are closed, so that digestion is carried out in the closed reaction chamber, and the digestion time is shortened;

in the titration stage, a conveying pump conveys gas into the reaction chamber through a first pipeline in the titration process;

meanwhile, a first quantitative pump quantifies the potassium permanganate solution, sequentially passes through a second pipeline and a first pipeline, mixes the gas and enters the reaction chamber;

in the titration process, the potassium permanganate solution enters the reaction chamber in the following mode:

a water sample and a digestion solution enter the reaction chamber from the first inlet;

after digestion is finished, obtaining the light absorption value A of the solution in the reaction chamber_x；

Using absorbance value A_xAnd obtaining the predicted concentration C of the water sample by the first mapping relation between the water sample concentration C and the light absorption value A_{Preparation of}；

Using the predicted concentration C_{Preparation of}And obtaining a second mapping relation between the water sample concentration C and the titration end point volume V to obtain a titration end point prediction volume V_{Preparation of}；

At a first speed v₁Adding a potassium permanganate solution into the reaction chamber, wherein the volume of the added potassium permanganate solution is V₁，1<V_{Preparation of}/V₁<2, e.g. V_{Preparation of}/V₁＝1.25

At a first speed v₂Adding a potassium permanganate solution to the reaction chamber, v₂<v₁Until the obtained light absorption value of the solution in the reaction chamber is greater than a threshold value, so as to obtain a titration end point volume V;

and obtaining the permanganate index of the water sample by utilizing the volume V and the second mapping relation.

The first mapping relation and the second mapping relation are obtained in the following mode:

sending the first standard solution and the digestion solution to the reaction chamber, and obtaining a solution light absorption value A in the reaction chamber after digestion is finished₁；

Adding a reducing agent into the reaction chamber, titrating, and obtaining a light absorption value A of the solution after each titration until the light absorption value A exceeds a threshold value to obtain a titration end point volume V₁₁；

Obtaining a light absorption value A of the second standard solution in the digestion container by using the method₂And titration end point volume V₂₂；

And obtaining a first mapping relation between the water sample concentration C and the light absorption value A and a second mapping relation between the water sample concentration C and the titration end point volume V by using the first standard solution and the second standard solution, the light absorption value and the titration end point volume.