Method for determining number of bacteria in cathode electrophoretic paint

Abstract

The invention provides a method for determining the number of bacteria in cathode electrophoretic paint. The method comprises the steps that a relation model of the hydrogen ion concentration and the number of bacteria in the cathode electrophoretic paint is determined; the real-time pH value of the cathode electrophoretic paint is obtained; based on the real-time pH value, the real-time hydrogen ion concentration in the cathode electrophoretic paint is obtained; and determining the real-time bacterial quantity in the cathode electrophoretic paint based on the relation model and the real-time hydrogen ion concentration. According to the method for determining the number of the bacteria in the cathode electrophoretic paint, the real-time hydrogen ion concentration in the cathode electrophoretic paint is obtained by collecting the pH value data of the cathode electrophoretic paint in real time, and then the real-time number of the bacteria in the cathode electrophoretic paint is obtained according to the relation model of the hydrogen ion concentration and the number of the bacteria in the cathode electrophoretic paint. According to the method, the number of bacteria in the cathode electrophoretic paint can be obtained in time, the operation is simple, and the cost is relatively low.

Description

Technical Field

[0001] The present application relates to the field of coating technology, and in particular to a method for determining the number of bacteria in cathode electrophoretic paint. Background Art

[0002] Cathodic electrophoretic paint is widely used due to its excellent construction performance and anti-corrosion performance. In order to meet the increasingly stringent environmental protection requirements and low carbon emission requirements, electrophoretic paint manufacturers have developed formulas that do not contain heavy metals such as lead. At the same time, closed circulation and zero emissions are achieved during the electrophoretic coating process. These factors that can effectively inhibit bacterial growth are reduced, making electrophoretic paint more likely to breed bacteria. If the electrophoretic system breeds bacteria, due to the multiplication characteristics of bacterial reproduction, once the bacteria break out, the electrophoretic tank liquid will age rapidly, the stability will decrease, and the electrophoretic body will become rough, thus causing batch roughness defects of the body. Therefore, it is particularly important to be able to quickly detect the number of bacteria and then take targeted measures to sterilize.

[0003] The bacterial test piece detection method is currently widely used in the detection of the number of bacteria in cathode electrophoretic paint. The detection method is to take a bacterial test piece and immerse it in the tank liquid sample, then put the immersed test piece into a constant temperature incubator, incubate it in the dark at 30℃ for 3-6 days, and compare it with the standard picture of the number of bacteria (such as Figure 1 As shown), the cathode electrophoresis bacteria data was obtained. Bacterial content>10 3 CFU / ml, the tank liquid begins to multiply bacteria in large quantities, and preventive sterilization is required. The bacterial content is ≥10 7 When the CFU / ml is less than 10%, the trough liquid is seriously infected with bacteria and must be sterilized as soon as possible. However, the bacterial test strip detection method is accurate but time-consuming, requiring at least 3 days and generally 6 days to produce results. By the time the test results come out, the bacteria have grown slowly in the early stage and explosively in the later stage, missing the best sterilization time.

[0004] Another method for detecting the number of cells is the ATP rapid bacterial method. The detection principle is that all bacterial cells contain ATP (adenosine triphosphate). The higher the ATP, the stronger the fluorescence emitted by the reaction of ATP and luciferin-luciferase, thereby detecting the number of bacteria and other microorganisms contained in the sample. The ATP bacterial detection method is easy to operate, highly sensitive, and can quickly produce test results, but this method has a high detection cost and is easily interfered by other organic matter, which limits the further promotion of this method. Summary of the invention

[0005] To at least partially solve the above problems, an embodiment of the present application provides a method for determining the number of bacteria in cathode electrophoretic paint, including: determining a relationship model between the hydrogen ion concentration and the number of bacteria in the cathode electrophoretic paint; obtaining the real-time pH value of the cathode electrophoretic paint; based on the real-time pH value, obtaining the real-time hydrogen ion concentration in the cathode electrophoretic paint; based on the relationship model and the real-time hydrogen ion concentration, determining the real-time number of bacteria in the cathode electrophoretic paint.

[0006] In some embodiments, determining a relationship model between hydrogen ion concentration and bacterial count in cathode electrophoretic paint includes: obtaining a plurality of fitting data, each fitting data including the bacterial count in cathode electrophoretic paint and the hydrogen ion concentration corresponding to the bacterial count; and fitting using the plurality of fitting data to determine the relationship model.

[0007] In some embodiments, multiple fitting data are used for fitting to determine the relationship model, including: establishing a fitting relationship, where the fitting relationship is a linear relationship; bringing the multiple fitting data into the fitting relationship for fitting, obtaining the coefficients of the linear relationship to determine the relationship model.

[0008] In some embodiments, the relationship model is: c[H + ]*10 6 =-a*lg(10 x )+b, where c[H + ] is the hydrogen ion concentration, 10 x is the number of bacteria, a and b are the coefficients of the linear relationship.

[0009] In some embodiments, the linear fitting correlation coefficient R of the relationship model 2 ≥95%.

[0010] In some embodiments, when obtaining the fitting data, the number of bacteria in the cathode electrophoretic paint is obtained by a bacterial test piece test.

[0011] In some embodiments, obtaining the real-time pH value of the cathode electrophoretic paint includes: obtaining the real-time pH value of the cathode electrophoretic paint by a pH meter within a temperature range of 20-25°C.

[0012] In some embodiments, the method further comprises: calibrating the pH meter at predetermined intervals.

[0013] In some embodiments, when performing calibration, three standard buffer solutions with pH values ​​of 4.01, 6.86, and 9.18 at 25° C. are used for three-point calibration.

[0014] In some embodiments, the real-time number of bacteria in the cathode electrophoretic paint is determined based on the relationship model and the real-time hydrogen ion concentration, including: when the fluctuation amplitude of the real-time hydrogen ion concentration relative to the standard hydrogen ion concentration exceeds a preset value, the real-time number of bacteria in the cathode electrophoretic paint is determined based on the relationship model and the real-time hydrogen ion concentration, wherein the standard hydrogen ion concentration is determined based on an empirical value.

[0015] The embodiment of the present application provides a method for determining the number of bacteria in cathode electrophoretic paint. The real-time hydrogen ion concentration in the cathode electrophoretic paint is obtained by collecting the pH value data of the cathode electrophoretic paint in real time, and then the real-time number of bacteria in the cathode electrophoretic paint is obtained based on the relationship model between the hydrogen ion concentration and the number of bacteria in the cathode electrophoretic paint. This method can obtain the number of bacteria in the cathode electrophoretic paint in a timely manner, and is simple to operate and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 This is a schematic diagram of the bacterial count standard image used in the bacterial test strip detection method. From left to right, there are 10 3 , 10 4 , 10 5 , 10 6 , 10 7 Schematic representation of a standard picture of bacterial counts;

[0018] Figure 2 It is a schematic diagram of the relationship curve between hydrogen ion concentration and bacterial number provided in the embodiment of the present application. DETAILED DESCRIPTION

[0019] The technical scheme of the preferred embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection claimed in the present application.

[0020] The inventor of the present application has found that the pH value of the cathode electrophoretic paint widely used in the current industry is 5-7, and the operating temperature is 25-32°C, which provides an ideal growth environment for the reproduction of thermophilic and acidophilic microorganisms. Therefore, the bacteria in the cathode electrophoretic paint are mainly acidophilic bacteria. If bacteria breed in the cathode electrophoretic paint, they will consume the hydrogen ions in the cathode electrophoretic paint, resulting in a decrease in the hydrogen ion concentration of the cathode electrophoretic paint, causing the pH value of the cathode electrophoretic paint to increase. That is, as the number of bacteria increases, the hydrogen ions (H + ) concentration decreased, and the two were negatively correlated.

[0021] In view of this, an embodiment of the present application provides a method for determining the number of bacteria in cathode electrophoretic paint, including: determining a relationship model between hydrogen ion concentration and bacterial number in cathode electrophoretic paint; obtaining a real-time pH value of cathode electrophoretic paint; obtaining the real-time hydrogen ion concentration in cathode electrophoretic paint based on the real-time pH value; determining the real-time number of bacteria in cathode electrophoretic paint based on the relationship model and the real-time hydrogen ion concentration. When obtaining the real-time hydrogen ion concentration in cathode electrophoretic paint based on the real-time pH value, it can be based on pH=-lg(c[H + ]) to obtain the hydrogen ion concentration, where c[H + ] is the hydrogen ion concentration.

[0022] The embodiment of the present application provides a method for determining the number of bacteria in cathode electrophoretic paint. The real-time hydrogen ion concentration in the cathode electrophoretic paint is obtained by collecting the pH value data of the cathode electrophoretic paint in real time, and then the real-time number of bacteria in the cathode electrophoretic paint is obtained based on the relationship model between the hydrogen ion concentration and the number of bacteria in the cathode electrophoretic paint. This method can obtain the number of bacteria in the cathode electrophoretic paint in a timely manner, and is simple to operate and low in cost.

[0023] In some embodiments, determining a relationship model between hydrogen ion concentration and the number of bacteria in cathode electrophoretic paint includes: obtaining multiple fitting data, each fitting data includes the number of bacteria in cathode electrophoretic paint and the hydrogen ion concentration corresponding to the number of bacteria; using multiple fitting data for fitting to determine the relationship model. In this embodiment, the relationship model is fitted by fitting data, and the fitting data includes the number of bacteria and the hydrogen ion concentration corresponding to the number of bacteria. By fitting multiple fitting data, the relationship between the number of bacteria and the hydrogen ion concentration can be obtained, thereby obtaining the relationship model. In this embodiment, the specific fitting method is not limited. Exemplarily, fitting can be performed by linear regression, polynomial regression, etc.

[0024] In some embodiments, multiple fitting data are used for fitting to determine the relationship model, including: establishing a fitting relationship, where the fitting relationship is a linear relationship; bringing multiple fitting data into the fitting relationship for fitting, obtaining the coefficients of the linear relationship, and determining the relationship model. In this embodiment, by establishing a linear fitting relationship, the relationship between the hydrogen ion concentration and the number of bacteria can be obtained more conveniently and accurately.

[0025] In some embodiments, the relationship model is: c[H + ]*10 6 =-a*lg(10 x )+b, where c[H + ] is the hydrogen ion concentration, 10 x is the number of bacteria, a and b are the coefficients of the linear relationship. In this application, lgA means: the logarithm of A with base 10, that is, the common logarithm of A. In this embodiment, by taking the common logarithm of the number of bacteria and multiplying the hydrogen ion concentration by 10 6 , which can facilitate the calculation of coefficients a and b, simplify the fitting process and reduce the difficulty of fitting.

[0026] In some embodiments, the linear fitting correlation coefficient R of the relationship model 2 ≥95%. Linear fitting correlation coefficient R 2 Also known as the coefficient of determination, it is an indicator used to measure the degree of fit of a linear regression model to the observed data. 2 It can be obtained by the following formula:

[0027]

[0028] Among them, SS res is the residual sum of squares, which represents the sum of squares of the differences between the model predictions and the observed values; SS tot is the total sum of squares, which represents the sum of squares of the differences between the observed values ​​and the observed mean. 2 ≥95%, which can ensure that the obtained relationship model can better explain the changes in the fitting data and improve the accuracy of the prediction of the relationship model.

[0029] In some embodiments, when obtaining fitting data, the number of bacteria in the cathode electrophoretic paint is obtained by a bacterial test piece test. In this embodiment, when obtaining fitting data, the number of bacteria is obtained by a bacterial test piece test, which can make the collected bacterial number data more accurate, thereby ensuring the prediction accuracy of the relationship model; the hydrogen ion concentration corresponding to the number of bacteria can be obtained by calculating the hydrogen ion concentration through the pH value collected by the pH meter. A pH meter is an instrument for measuring the acidity and alkalinity of a solution, which determines its acidity and alkalinity by measuring the hydrogen ion concentration in the solution. The working principle of a pH meter is generally based on the potential difference between a glass electrode and a reference electrode. There is a special glass film on the glass electrode, and inside it is a salt solution containing a certain concentration of hydrogen ions. When the glass electrode is immersed in the solution, the hydrogen ions in the water molecules are exchanged with the hydrogen ions in the glass film, causing the potential on the electrode surface to change. This changing potential is proportional to the hydrogen ion concentration in the solution, so that the pH value of the solution can be calculated.

[0030] Specifically, a test plan can be designed to use a bacterial test piece to test the number of bacteria in the cathode electrophoresis tank liquid, and a pH meter can be used to detect the pH value of the cathode electrophoresis tank liquid with different numbers of bacteria, and the formula pH = -lg (c [H +]) is used to calculate the concentration of hydrogen ions (H +) in the cathode electrophoresis tank liquid. Table 1 shows a specific example of fitting data collected for a coating workshop.

[0031] Table 1

[0032]

[0033] The data in Table 1 are fitted and the fitting results are as follows: Figure 2 As shown, from Figure 2 It can be seen that the relationship model between the hydrogen ion concentration and the number of bacteria in the cathode electrophoresis line of a coating workshop is y=-0.32x+4.45, and the linear fitting correlation coefficient R 2 It is 97%.

[0034] In some embodiments, obtaining the real-time pH value of the cathode electrophoretic paint includes: obtaining the real-time pH value of the cathode electrophoretic paint by a pH meter within a temperature range of 20-25° C. In this embodiment, by controlling the temperature range and measuring at a temperature of the cathode electrophoretic paint under normal operating conditions, the influence of temperature on the pH value measurement value can be reduced.

[0035] In some embodiments, the method further comprises: calibrating the pH meter at predetermined intervals. In this embodiment, the reliability of the data collected by the pH meter can be ensured by regularly calibrating the pH meter. Exemplarily, the predetermined time can be 1 day, 3 days, 1 week, 1 month, etc., and can be adjusted according to actual conditions.

[0036] In some embodiments, three standard buffer solutions with pH values ​​of 4.01, 6.86, and 9.18 at 25° C. are used for three-point calibration. In this embodiment, the three standard buffer solutions are relatively easy to obtain and can be used to conveniently calibrate the pH meter.

[0037] In some embodiments, the real-time number of bacteria in the cathode electrophoretic paint is determined based on the relationship model and the real-time hydrogen ion concentration, including: when the fluctuation range of the real-time hydrogen ion concentration relative to the standard hydrogen ion concentration exceeds a preset value, the real-time number of bacteria in the cathode electrophoretic paint is determined based on the relationship model and the real-time hydrogen ion concentration, wherein the standard hydrogen ion concentration is determined based on an empirical value. In this embodiment, by monitoring the variation range of the hydrogen ion concentration, when the fluctuation is small, no operation is required, thereby filtering out the situation when the hydrogen ion concentration fluctuates normally, reducing the workload when monitoring the bacterial concentration.

[0038] The method for determining the number of bacteria in cathode electrophoretic paint provided in the embodiment of the present application is simple to operate, has low detection cost, and can quickly detect the number of bacteria. In actual production, due to the multiplication characteristics of bacterial reproduction, once a bacterial outbreak occurs, the electrophoretic bath liquid will age rapidly, the stability will decrease, and the electrophoretic body will become rough, thereby causing a batch of rough defects in the body. The method provided in the embodiment of the present application can quickly determine whether bacteria are growing in the bath liquid, so as to start the sterilization operation at the first time.

[0039] Based on the above-mentioned embodiments of the present application, in the absence of explicit negation or conflict, the technical features of one embodiment may be beneficially combined with one or more other embodiments.

[0040] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are only for illustration and not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A method for determining the number of bacteria in cathodic electrophoretic paint, characterized in that: include: Determining a relationship model between the hydrogen ion concentration and the number of bacteria in the cathode electrophoretic paint; Obtaining the real-time pH value of the cathode electrophoretic paint; Based on the real-time pH value, obtaining the real-time hydrogen ion concentration in the cathode electrophoretic paint; Based on the relationship model and the real-time hydrogen ion concentration, the real-time bacteria quantity in the cathode electrophoretic paint is determined.

2. The method according to claim 1, characterized in that Determining the relationship model between the hydrogen ion concentration and the number of bacteria in the cathode electrophoretic paint comprises: Acquire a plurality of fitting data, each of the fitting data comprising the number of bacteria in the cathode electrophoretic paint and the hydrogen ion concentration corresponding to the number of bacteria; The relationship model is determined by performing fitting using a plurality of the fitting data.

3. The method according to claim 2, characterized in that Using the plurality of fitting data to perform fitting to determine the relationship model comprises: Establishing a fitting relationship, wherein the fitting relationship is a linear relationship; A plurality of the fitting data are brought into the fitting relationship equation for fitting, and the coefficients of the linear relationship equation are obtained to determine the relationship model.

4. The method according to claim 3, characterized in that The relationship model is: c[H + ]*10 6 =-a*lg(10 x )+b, Among them, c[H + ] is the hydrogen ion concentration, 10 x is the number of bacteria, a and b are the coefficients of the linear relationship.

5. The method according to claim 4, characterized in that The linear fitting correlation coefficient R of the relationship model 2 ≥95%.

6. The method according to claim 2, characterized in that When obtaining the fitting data, the number of bacteria in the cathode electrophoretic paint is obtained by means of a bacteria test piece test.

7. The method according to claim 1, characterized in that Obtaining the real-time pH value of the cathode electrophoretic paint comprises: obtaining the real-time pH value of the cathode electrophoretic paint by a pH meter within a temperature range of 20-25°C.

8. The method according to claim 7, characterized in that Also includes: The pH meter is calibrated at predetermined intervals.

9. The method according to claim 7, characterized in that: When performing calibration, three-point calibration was performed using three standard buffer solutions of pH = 4.01, pH = 6.86, and pH = 9.18 at 25°C.

10. The method according to claim 1, characterized in that Determining the real-time number of bacteria in the cathode electrophoretic paint based on the relationship model and the real-time hydrogen ion concentration includes: When the fluctuation amplitude of the real-time hydrogen ion concentration relative to the standard hydrogen ion concentration exceeds a preset value, the real-time bacteria quantity in the cathode electrophoretic paint is determined based on the relationship model and the real-time hydrogen ion concentration, wherein the standard hydrogen ion concentration is determined based on an empirical value.

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