System and method for detecting harmful components of plant nourishing hair dye

Abstract

The invention discloses a plant nourishing type hair dye and a harmful component detection method, belongs to the technical field of chemical component detection of hair dyes, and aims to solve the problem of harmful component detection of hair dyes. The detection system comprises a terminal controller, an A / D conversion module, a single-chip microcomputer control system, a flow controller, a control chip, a gas detection unit, a heating temperature setting module, an adjusting module, an instrument amplifier, a relay switch, a heating furnace, a tubular SOFC monitor, a control chip, a flow controller, a temperature sensor, a pressure sensor, a gas valve and a gas detection unit. According to the hair dye detection system, the harmful ingredients of the hair dye can be effectively detected, and the detection capability of the hair dye is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of chemical component detection technology for hair dyes, and more specifically to a plant-based nourishing hair dye and a method for detecting harmful components. Background Technology

[0002] Hair dye is a cosmetic used to color hair. With rising living standards, hair dyeing has become a fashionable choice for more and more people of all ages. However, traditional hair dyes contain benzene compounds such as phenylenediamine, para-aminophenol, and hydroquinone. These substances are toxic, and long-term use can lead to various diseases, such as hair loss, skin allergies, and even cancer. Therefore, safe and effective natural plant-based hair dyes are more appealing to consumers and represent the future direction of high-safety hair dye development. Besides their coloring function, many natural plant pigments are also effective antibacterial, antioxidant, anti-allergenic, and hair-nourishing ingredients.

[0003] Patent CN201811357771.0 discloses a plant-based hair dye, composed of a dyeing agent and a color developer. The dye component is a dyeing combination drug containing at least one of gallnut, tea, and burnet root. The color developer contains ferrous ions. The pigment used in this plant-based hair dye is a plant pigment and does not contain p-phenylenediamine-based oxidative dyes. However, it does not consider the color mixing and hair-nourishing effects of the plant-based dye. Therefore, a plant-based nourishing hair dye is needed to meet the color dyeing needs of various age groups and nourish the hair. In the application of hair dyes, the main harmful components in chemical hair dyes are lead, mercury, and p-phenylenediamine, which are chemical components that seriously endanger human health. Among the main components of hair dyes, core compounds such as p-phenylenediamine and hydrogen peroxide can affect hematopoietic stem cells and are recognized carcinogens. When users use this hair dye, although it can fix the color to some extent, it is also a strong allergen and has a carcinogenic effect on the body. Therefore, how to test the chemical components of hair dye has become an urgent problem to be solved. Summary of the Invention

[0004] To address the shortcomings of the aforementioned technologies, this invention discloses a plant-based nourishing hair dye and a method for detecting harmful components, which can effectively detect harmful components in hair dye and greatly improve the detection capability of hair dye.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A system for detecting harmful chemicals in hair dyes, wherein the detection system includes:

[0007] Terminal controller, A / D conversion module, microcontroller control system, flow controller, control chip, gas detection unit, heating temperature setting module, adjustment module, instrumentation amplifier, relay switch, heating furnace, tubular SOFC monitor, control chip, flow controller, temperature sensor, pressure sensor, gas valve, gas detection unit, heating temperature setting module, interface display module, data interaction module and mobile terminal;

[0008] The temperature sensor, pressure sensor, and gas valve are connected to the flow controller, which in turn is connected to the control chip. The control chip is connected to the gas detection unit, the heating temperature setting module, and the interface display module, respectively. The control chip is also connected to the data interaction module, which is connected to the mobile terminal. The tubular SOFC monitor is connected to the heating furnace, which is connected to a relay switch. The relay switch is connected to the terminal controller via a microcontroller control system. The instrumentation amplifier displays the temperature status of the heating furnace. The detection system operates as follows:

[0009] The hair dye sample to be tested is input into the test pipeline. Under the control of the gas valve, the pressure sensor senses the pressure data in the test pipeline, and the temperature sensor senses the temperature data in the test pipeline. The control chip controls the working status of the flow controller. The control chip interacts with the mobile terminal through the data interaction module. The control chip also controls the working status of the gas detection unit, the heating temperature setting module, and the interface display module. The tubular SOFC monitor is used to detect the hair dye data in the test pipeline. The flow information is obtained through the adjustment module, and the flow detection status is controlled or detected by the terminal controller. The detection process is evaluated using Bernoulli's equation.

[0010] The gas detection unit detects the composition of the steam gas of the hair dye when it is heated.

[0011] Data information is exchanged between the terminal controller and the mobile terminal.

[0012] As a further technical solution of the present invention, the detection method includes the following steps:

[0013] Step 1: The hair dye to be tested is fed into the test pipeline as a hair dye fluid. The target colorant, obtained by mixing black, yellow, red, and blue colorants in proportion according to the target color, is chemically extracted. The flow rate, temperature, and pressure in the test pipeline are sensed by a flow controller, temperature sensor, and pressure sensor, respectively. The dye is tested in either liquid or gaseous state, and the composition of the hair dye or gaseous components is detected. The extraction methods include hydride atomic fluorescence spectrometry, mercury analysis, or cold vapor atomic absorption spectrometry.

[0014] Step 2: Extract the chemical substances from the mixed target colorant and dyeing base paste; detect the lead content using graphite furnace atomic absorption spectrophotometry or flame atomic absorption spectrophotometry.

[0015] Step 3: Keep your hair clean and use a comb to apply the hair dye evenly from the roots; use hydride atomic fluorescence spectrometry to detect the arsenic content in the clean hair.

[0016] Step 4: Wrap your hair in a damp towel at room temperature for one hour and then rinse it clean, or wrap your hair in a heated cap for thirty-five minutes and then rinse it clean; detect the formaldehyde content by acetylacetone spectrophotometry or high performance liquid chromatography.

[0017] Step 5: After rinsing, keep the hair at 50% humidity and test the hair at 50% humidity. The content of asbestos from hair dye remaining in the hair after washing is detected by a combination of X-ray diffraction and polarized light microscopy.

[0018] As a further technical solution of the present invention, the working method of hydride atomic fluorescence spectrometry is as follows:

[0019] Prepare standard solutions III: 0 mL, 0.50 mL, 1.25 mL, 2.50 mL, and 5.00 mL are placed in 25 mL stoppered colorimetric tubes. Add 2.5 mL of hydrochloric acid and dilute with water to the mark to obtain a series of mercury standard solutions with corresponding concentrations of 0 μg / L, 0.20 μg / L, 0.50 μg / L, 1.00 μg / L, and 2.00 μg / L. Weigh 0.5 g to 1 g of sample into a cleaned polytetrafluoroethylene sample dissolving cup. First, place the sample in a temperature-adjustable 100℃ constant temperature electric heater or water bath to evaporate the mercury. Then, irradiate the sample with a mercury hollow cathode lamp. The intensity of the irradiation is directly proportional to the mercury content. Quantify the sample by comparing it with the standard series.

[0020] The working method of the mercury analyzer is as follows: it detects the concentration of gaseous reactive mercury and particulate mercury in a gaseous state, achieving high-resolution online continuous observation of trace mercury in the air, with a detection range of 0.1-10000 ng / m³. 3 At that time, the minimum detection limit for mercury was <0.1 ng / m³. 3 ;

[0021] The working method of cold atomic absorption spectrometry is as follows: taking advantage of the different boiling points of the components in a mixed liquid or liquid-solid system, the low-boiling-point component is evaporated and then condensed to separate the entire component. Air or nitrogen is introduced at room temperature to vaporize metallic mercury, which is then loaded into a cold atomic absorption mercury analyzer to absorb ultraviolet light at 253.7 nm generated by a mercury lamp. Within a certain concentration range, the mercury concentration and absorbance have a linear relationship. The mercury content in the sample is determined using the standard curve method.

[0022] As a further technical solution of the present invention, the working method of graphite furnace atomic absorption spectrophotometry is as follows:

[0023] Samples of hair dyeing equipment were collected using a glass fiber filter cartridge and prepared into a sample solution through dry ashing digestion or wet digestion. Beryllium was atomized in a graphite tube at high temperature and absorbed the characteristic spectral line 234.9 nm emitted from a beryllium hollow cathode lamp in the optical path. The intensity of the characteristic spectral line was determined by atomic absorption spectrophotometry based on the change in intensity of the characteristic spectral line.

[0024] The working method of flame atomic absorption spectrophotometry is as follows:

[0025] The detection limit for lead in the ambient air surrounding hair dye gas was 0.5 μg / m³, and the sampling volume was 50 m³. 3 The minimum detectable concentration during the assay was 5 × 10⁻⁶. -4 mg / m 3 At that time, it was considered that the lead content exceeded the standard.

[0026] As a further technical solution of the present invention, the detection method of acetylacetone spectrophotometry is as follows:

[0027] (1) Collect the air gas evaporated from the hair dye device to be tested and prepare a formaldehyde stock solution; (2) Prepare an acetylacetone solution; (3) Dilute the formaldehyde stock solution and transfer it to an evaporating dish, and then place the evaporating dish in a sealed box; (4) React the formaldehyde in the sealed box with the acetylacetone solution in different volumes, and measure the absorbance at the same time; (5) Make a blank control and measure the absorbance.

[0028] The detection method using high performance liquid chromatography is as follows:

[0029] When setting the mobile phase methanol density to 0.03 mol / L, the ammonium acetate flow rate to 1.2 ml / min, the column temperature to 25℃, and the wavelength programs to 0-4.2 min, 238 nm, 5-7.5 min, 405 nm, 7.6-9.35 min, 530 nm; 9.35-9.8 min, 295 nm, 10.1-11.2 min, or 628 nm, benzoic acid, phenylenediamine, lead, or mercury in hair dye are determined. A detection limit of ≤0.3 ng for phenylenediamine is considered acceptable.

[0030] As a further technical solution of the present invention, the method of combining X-ray diffraction measurement and polarizing microscope observation is to first perform X-ray diffraction measurement and record the measured data, and then observe the data through a polarizing microscope and record the measured data. The data recorded by the two methods are compared to obtain the detection data of harmful components in hair dye.

[0031] As a further technical solution of the present invention, the evaluation is carried out through the following method during the detection process:

[0032] The hair dye is pumped into the test pipeline by a pressure pump. The transmission of the hair dye liquid in the test pipeline requires the pump station to provide pressure. The pressure is used to overcome the frictional resistance in the test pipeline by calculating the fluid movement of the hair dye using Bernoulli's equation. Since the local frictional resistance is mainly generated when the hair dye liquid flows through the valves and the curved test pipeline, the number of valves and bends in the long test pipeline is small, so the wear is also less.

[0033] The friction function along the test pipe for the hair dye flow rate is:

[0034]

[0035] In formula (1), V represents the velocity of the hair dye fluid in the test pipe, D represents the inner diameter of the test pipe, λ represents the coefficient of the hair dye flow friction, and the value of λ is related to R, the hair dye flow friction; the R function is expressed as:

[0036]

[0037] In formula (2), υ is the kinematic viscosity of the hair dye fluid, Q is the volumetric flow rate of the hair dye fluid, and the frictional loss is converted into pressure loss P as follows:

[0038]

[0039] In formula (3), ρ represents the density of the hair dye liquid. If the local friction between different test pipes is not considered, the internal pressure at a distance L from the test pipe can be calculated:

[0040]

[0041] In formula (4), P o Δz represents the pressure at which the hair dye liquid flows out, and Δz represents the high potential energy difference.

[0042] During the operation of the test pipeline, the internal pressure decreases with increasing distance, reaching its minimum at the starting point and then gradually decreasing. When the levels of heavy metal elements that endanger human health are the same, the first segment of the test pipeline has the greatest impact on the test pipeline, and the impact gradually decreases with increasing distance. Therefore, the risk values ​​differ in each section of the hair dye liquid test pipeline.

[0043] The pressure at the heavy metal element location in the test pipeline was calculated through mechanical analysis, providing a basis for the repair and replacement of the test pipeline for hair dye liquid.

[0044] When the pressure coefficient of the test pipeline for hair dye liquid is expressed as:

[0045] P sw =P f / F s(5)

[0046] In formula (5), P sw F represents the pressure coefficient indicating the safe operation of the test pipeline. s P represents the safety factor. f This represents the failure pressure of the test pipeline at the heavy metal element location. The failure pressure function is:

[0047] P f =P0R s (6)

[0048] In formula (6), P0 is the destructive pressure of the normal test pipeline, and R s The residual strength coefficient of the test pipe for hair dye liquid is related to the test pipe as follows:

[0049]

[0050] In formula (7), L is the length of the test pipe containing hair dye with a content that endangers human health, t is the wall thickness of the test pipe, D is the outer diameter of the test pipe, and d is the depth of the test pipe containing hair dye with a content that endangers human health.

[0051] The formula for calculating the internal pressure that a test pipeline carrying a liquid hair dye that poses a chemical hazard to human health can withstand is as follows:

[0052]

[0053] In formula (8), p represents the internal σ that the test pipeline can withstand. Ts Let Q be the tensile strength of the test pipe material, and Q be the correction factor for the length of the test pipe. The correction factor function is expressed as:

[0054]

[0055] When a test pipeline for hair dye liquid contains chemicals that may endanger human health, the formula for calculating the maximum safe operating pressure of the test pipeline is as follows:

[0056]

[0057] In formula (10), M is the expansion coefficient of the hair dye liquid test pipe under heating state, F is the design pressure bearing coefficient of the hair dye liquid test pipe, d is the depth of hair dye flow in the test pipe, and t is the wall thickness of the test pipe.

[0058] The positive and beneficial effects of this invention compared to existing technologies are as follows:

[0059] This invention discloses a plant-based nourishing hair dye and a method for detecting harmful components. It effectively detects harmful components in hair dyes, using graphite furnace atomic absorption spectrophotometry or flame atomic absorption spectrophotometry to detect lead content; hydride atomic fluorescence spectrophotometry to detect arsenic content in clean hair; acetylacetone spectrophotometry or high-performance liquid chromatography to detect formaldehyde content; and a combination of X-ray diffraction and polarized light microscopy to detect asbestos content left in hair dye after shampooing. The method also evaluates the detection process, significantly improving the detection capability of hair dyes. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0061] Figure 1 This is a schematic diagram of the principle architecture of a hair dye harmful chemical substance detection system according to the present invention;

[0062] Figure 2 This is a schematic diagram of a method for detecting harmful components in a plant-based nourishing hair dye according to the present invention;

[0063] Figure 3 This is a schematic diagram of X-ray diffraction data of tremolite asbestos in a sample of a plant-based nourishing hair dye according to the present invention.

[0064] Figure 4 This is a schematic diagram showing the detection of ions and the relative abundance ratio of ions in a sample of a plant-based nourishing hair dye according to the present invention. Detailed Implementation

[0065] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0066] In the above embodiments, such as Figure 1 As shown, a system for detecting harmful chemicals in hair dyes is provided, wherein the detection system includes:

[0067] Terminal controller, A / D conversion module, microcontroller control system, flow controller, control chip, gas detection unit, heating temperature setting module, adjustment module, instrumentation amplifier, relay switch, heating furnace, tubular SOFC monitor, control chip, flow controller, temperature sensor, pressure sensor, gas valve, gas detection unit, heating temperature setting module, interface display module, data interaction module and mobile terminal;

[0068] The temperature sensor, pressure sensor, and gas valve are connected to the flow controller, which in turn is connected to the control chip. The control chip is connected to the gas detection unit, the heating temperature setting module, and the interface display module, respectively. The control chip is also connected to the data interaction module, which is connected to the mobile terminal. The tubular SOFC monitor is connected to the heating furnace, which is connected to a relay switch. The relay switch is connected to the terminal controller via a microcontroller control system. The instrumentation amplifier displays the temperature status of the heating furnace. The detection system operates as follows:

[0069] The hair dye sample to be tested is input into the test pipeline. Under the control of the gas valve, the pressure sensor senses the pressure data in the test pipeline, and the temperature sensor senses the temperature data in the test pipeline. The control chip controls the working status of the flow controller. The control chip interacts with the mobile terminal through the data interaction module. The control chip also controls the working status of the gas detection unit, the heating temperature setting module, and the interface display module. The tubular SOFC monitor is used to detect the hair dye data in the test pipeline. The flow information is obtained through the adjustment module, and the flow detection status is controlled or detected by the terminal controller. The detection process is evaluated using Bernoulli's equation.

[0070] The gas detection unit detects the composition of the steam gas of the hair dye when it is heated.

[0071] Data information is exchanged between the terminal controller and the mobile terminal.

[0072] In a specific embodiment, a multi-functional module is established through functional analysis of the TMS32+XD129 combined chip. With the constituent chip as the core, data communication is achieved with the constituent chip through analysis of the detection system environment and gas chamber. Sensing information is input to the constituent chip via analog-to-digital demodulation. The sensing device is installed in the heating window, primarily collecting data on ambient temperature, gas pressure, and the gas valves of the detection system. The receiving module is equipped with RS485 and RS232 communication ports for data reception. After subsequent analysis and transmission, the results are finally loaded onto the demonstration interface for easy detection of hair dye gases.

[0073] The SOFC monitor incorporates a heating furnace to provide the operating temperature. The output signal from the K-type thermocouple is amplified by an instrumentation amplifier and sampled using an AD976 chip. A comparison between the setpoint and the real-time operating temperature of 700°C is made so that the proportional-integral-derivative module implemented in the S3C2440 CPU outputs a pulse-width modulation signal to the DC solid-state relay to control furnace heating. The SOFC monitor's output signal, approximately 200–300 mV, is directly sampled by the ADS1256 24-bit analog-to-digital converter without further amplification to avoid noise. A voltage follower is used for isolation, increasing input impedance and improving the monitor's load capacity. The digital signal is encapsulated in RS232 format and transmitted to a computer for data processing to identify hair dye gases. This allows for the detection of the hair dye gases.

[0074] This invention constructs a detection system that simulates a virtual environment where hair dye components can be detected under arbitrary heating conditions, i.e., at any temperature. In a specific embodiment, since the degree of hair dye volatilization varies at different temperatures, hair dye gas detection is achieved under different gas conditions.

[0075] In the above embodiments, such as Figure 2 As shown, a method for detecting harmful components in plant-based hair dyes includes the following steps:

[0076] Step 1: The hair dye to be tested is fed into the test pipeline as a hair dye fluid. The target colorant, obtained by mixing black, yellow, red, and blue colorants in proportion according to the target color, is chemically extracted. The flow rate, temperature, and pressure in the test pipeline are sensed by a flow controller, temperature sensor, and pressure sensor, respectively. The dye is tested in either liquid or gaseous state, and the composition of the hair dye or gaseous components is detected. The extraction methods include hydride atomic fluorescence spectrometry, mercury analysis, or cold vapor atomic absorption spectrometry.

[0077] Step 2: Extract the chemical substances from the mixed target colorant and dyeing base paste; detect the lead content using graphite furnace atomic absorption spectrophotometry or flame atomic absorption spectrophotometry.

[0078] Step 3: Keep your hair clean and use a comb to apply the hair dye evenly from the roots; use hydride atomic fluorescence spectrometry to detect the arsenic content in the clean hair.

[0079] Step 4: Wrap your hair in a damp towel at room temperature for one hour and then rinse it clean, or wrap your hair in a heated cap for thirty-five minutes and then rinse it clean; detect the formaldehyde content by acetylacetone spectrophotometry or high performance liquid chromatography.

[0080] Step 5: After rinsing, keep the hair at 50% humidity and test the hair at 50% humidity. The content of asbestos from hair dye remaining in the hair after washing is detected by a combination of X-ray diffraction and polarized light microscopy.

[0081] In a specific embodiment, this detection method involves examining the hair dye formula, analyzing the components of each formula or stage, and detecting key ingredients to achieve comprehensive analysis of the entire hair dye composition, significantly improving the ability to detect dye components. Furthermore, the hair dye preparation process is divided into different stages and components, and the different components of the prepared hair dye are tested separately. This staged measurement enhances the data information detection capability.

[0082] In the above embodiments, the working method of hydride atomic fluorescence spectrometry is as follows:

[0083] Prepare standard solutions III: 0 mL, 0.50 mL, 1.25 mL, 2.50 mL, and 5.00 mL are placed in 25 mL stoppered colorimetric tubes. Add 2.5 mL of hydrochloric acid and then add water to the mark to obtain a series of mercury standard solutions with corresponding concentrations of 0 μg / L, 0.20 μg / L, 0.50 μg / L, 1.00 μg / L, and 2.00 μg / L. Weigh 0.5 g to 1 g of the sample into a cleaned polytetrafluoroethylene sample dissolving cup. First, place the sample in a temperature-adjustable 100℃ constant temperature electric heater or water bath to evaporate the mercury. Then, irradiate the sample with a mercury hollow cathode lamp. The intensity of the irradiation is directly proportional to the mercury content. Quantify the sample by comparing it with the standard series.

[0084] In a specific embodiment, the experimental method was as follows: First, standard solution III was prepared, and standard solutions of different concentrations were prepared. The composition of the hair dye vapor output from the test pipeline was determined by hydride generation-atomic fluorescence spectrometry. The principle is based on the fact that tetravalent selenium is reduced to hydrogen selenide by a reducing agent under acidic conditions. When this hydrogen selenide is carried into the atomizer by a carrier gas, it is excited to a high-energy state under the irradiation of a selenium hollow cathode lamp. The characteristic of emitting fluorescence when it deactivates and returns to the ground state can be used to quantitatively detect the mercury content. 10 ml of hair dye was extracted and used five times consecutively. Observations were made, and details are shown in Tables 1 and 2.

[0085] Table 1. Illustration of hair color changes due to scalp oiliness.

[0086]

[0087]

[0088] The above experiments demonstrate that hydride generation-atomic fluorescence spectrometry can be used for phased detection of hair dye components. The average relative standard deviations of the repeated measurements in five experiments were 0.51%, 0.43%, and 0.32%, respectively. This indicates that the present invention has outstanding technical effects.

[0089] In the above embodiments, the working method of the mercury analyzer is as follows: the concentration of gaseous active mercury and particulate mercury in the gaseous state is detected to achieve high-resolution online continuous observation of ultra-trace mercury in the air of hair dye. When the detection range is 0.1-10000ng / m3, the minimum detection limit of mercury is <0.1ng / m3.

[0090] In specific embodiments, the low-concentration standard series consists of mercury standard stock solutions sequentially diluted with 1% nitric acid to obtain standard series of 0, 1.0, 5.0, 10.0, 25.0, and 50.0 ng / mL. The medium- and high-concentration standard series consists of mercury standard stock solutions sequentially diluted with 1% nitric acid to obtain standard series of 0, 50, 100, 150, 200 and 250, 500, 750, 1000, and 1500 ng / mL.

[0091] During the determination, 100 μL of each low-concentration standard series was sequentially taken into a quartz boat for analysis. The mercury content in 100 μL of standard solution was 0, 0.1, 0.5, 1.0, 2.5, and 5.0 ng, respectively. A low-concentration standard curve was plotted with fluorescence value on the ordinate and mercury content on the abscissa. Similarly, 100 μL of each medium-concentration and high-concentration standard series was sequentially taken into a quartz boat for analysis. The mercury content in 100 μL of standard solution was 0, 5, 10, 15, 20 and 25, 50, 75, 100, 150 ng, respectively. Medium-concentration and high-concentration standard curves were plotted with fluorescence value on the ordinate and mercury content on the abscissa. For the sample determination, 0.1 g of sample, accurate to 0.0001 g, was weighed into a pre-treated sample boat and introduced into a drying decomposition furnace via an autosampler. The determination was performed according to the instrument's reference conditions. The low-concentration standard curve was preferred for measurement; if the linear range was exceeded, a medium-concentration or high-concentration standard curve was then selected. The measurement results are either directly read from the data processing terminal or calculated using the following formula; the output function formula for the measurement results is:

[0092] x = ay - b (11)

[0093] In formula (11), x is the mass of mercury in the sample, in ng; y is the measured fluorescence value; a is the slope of the standard curve; b is the intercept of the standard curve; the output function formula for the analytical results is:

[0094]

[0095] In formula (12), ω is the mass fraction of mercury in the sample, and the unit is mg / kg; m is the sample amount, and the unit is g.

[0096] The recoveries of different matrices and concentrations ranged from 81.5% to 103.8%, with relative standard deviations ≤5% (n=6).

[0097] In the above embodiments, the working method of cold atomic absorption spectrometry is as follows: taking advantage of the different boiling points of the components in the mixed liquid or liquid-solid system, the low-boiling-point component is evaporated and then condensed to separate the entire component. Air or nitrogen is introduced at room temperature to vaporize metallic mercury, which is then loaded into a cold atomic absorption mercury analyzer to absorb 253.7 nm ultraviolet light generated by a mercury lamp. Within a certain concentration range, the mercury concentration and absorbance have a linear relationship. The mercury content in the sample is determined using the standard curve method.

[0098] In a specific embodiment, the method for preparing the standard series solutions is as follows:

[0099] Take 0 mL, 0.10 mL, 0.30 mL, 0.50 mL, 0.70 mL, 1.00 mL, and 2.00 mL of mercury standard solution III (3.12.4) and place them in a 100 mL Erlenmeyer flask or mercury vapor generator flask, and dilute to a certain volume with sulfuric acid.

[0100] Weigh 1 g of the sample (accurate to 0.001 g) into a 50 mL stoppered colorimetric tube. Prepare a reagent blank along with the sample. If the sample contains organic solvents such as ethanol, evaporate it at low temperature in a water bath or on a hot plate (do not allow it to dry out). Add 5.0 mL of nitric acid and 2.0 mL of hydrogen peroxide, and mix well. If the sample produces a large amount of foam, add a few drops of octanol. Heat in a boiling water bath for 2 hours, remove, add 1.0 mL of hydroxylamine hydrochloride solution, let stand for 15-20 minutes, add sulfuric acid, and dilute to 25 mL with water.

[0101] Adjust the mercury analyzer according to the instrument manual. Add the standard series solutions to the mercury vapor generator flask, add 2 mL of stannous chloride solution, and quickly seal the flask tightly. Open the instrument's vapor valve. Record the reading when the indicator reaches its highest value. Plot a standard curve. Pipette a measured amount of blank and sample solutions into the mercury vapor generator flask, add sulfuric acid to a specific volume, and perform the determination. The output function formula for the analytical results is:

[0102]

[0103] In formula (13), ω is the mass fraction of mercury in the sample; m1 is the mass of mercury in the test solution; m0 is the mass of mercury in the blank solution; V is the total volume of the sample digest solution; V1 is the volume of the sample digest solution taken; and M is the sample amount.

[0104] In the above embodiments, the working method of graphite furnace atomic absorption spectrophotometry is as follows:

[0105] Samples of hair dyeing equipment were collected using a glass fiber filter cartridge and prepared into a sample solution through dry ashing digestion or wet digestion. Beryllium was atomized in a graphite tube at high temperature and absorbed the characteristic spectral line 234.9 nm emitted from a beryllium hollow cathode lamp in the optical path. The intensity of the characteristic spectral line was determined by atomic absorption spectrophotometry based on the change in intensity of the characteristic spectral line.

[0106] In a specific embodiment, the method for preparing the standard series solutions is as follows:

[0107] Pour 1.0 mL of lead standard stock solution into a 100 mL volumetric flask and add nitric acid to the mark. Repeat this dilution process multiple times to prepare a series of lead standard solutions containing 4.00 ng, 8.00 ng, 12.0 ng, 16.0 ng, and 20.0 ng per mL.

[0108] The sample processing method is as follows:

[0109] For wet digestion, weigh 1.0g–2.0g of sample (accurate to 0.001g) and place it in a digestion tube, simultaneously preparing a reagent blank. If the sample contains organic solvents such as ethanol, evaporate it at low temperature in a water bath or on a hot plate. For cream-type samples, preheat in a water bath to melt the sample on the bottle wall and allow it to flow to the bottom. Add a few glass beads, then add 10mL of nitric acid. Digest from low to high temperature. When the digestion volume decreases to 2mL–3mL, remove the heat source and cool. Add 2mL–5mL of perchloric acid and continue heating and digesting, gently shaking occasionally to ensure homogeneity. Digest until white fumes are emitted and the digestion solution is pale yellow or colorless. Concentrate the digestion solution to approximately 1mL. After cooling to room temperature, quantitatively transfer to a 10mL (or 25mL for powder samples) stoppered colorimetric tube, and dilute to the mark with water. If the sample solution is turbid, centrifuge and collect the supernatant for analysis.

[0110] In the above embodiments, the working method of flame atomic absorption spectrophotometry is as follows:

[0111] When measuring lead in the ambient air of hair dye gas, the detection limit is 0.5 μg / m³, and the lowest detectable concentration is 5 × 10⁻⁴ mg / m³ when the sampling volume is 50 m³. In such cases, the lead content is considered to exceed the standard.

[0112] In a specific embodiment, the method for preparing the standard series solutions is as follows:

[0113] Take 0 mL, 0.50 mL, 1.00 mL, 2.00 mL, 4.00 mL, and 6.00 mL of lead standard solution II (3.8.3) and place them into 10 mL stoppered colorimetric tubes respectively. Add water to the mark to obtain a series of lead standard solutions with corresponding concentrations of 0 mg / L, 0.50 mg / L, 1.00 mg / L, 2.00 mg / L, 4.00 mg / L, and 6.00 mg / L.

[0114] Transfer the sample to a 10 mL stoppered colorimetric tube, wash the sample dissolving cup several times with water, combine the washing solutions, add 0.5 mL of hydroxylamine hydrochloride solution, and dilute to 10 mL with water for later use.

[0115] Weigh 1 g of sample (accurate to 0.001 g) into a 50 mL stoppered colorimetric tube. Prepare a reagent blank along with the sample. If the sample contains organic solvents such as ethanol, evaporate them at low temperature in a water bath or on a hot plate. If it is a cream-type sample, preheat it in a water bath to melt the sample on the tube wall and allow it to flow to the bottom of the tube. Add 5.0 mL of nitric acid and 2.0 mL of hydrogen peroxide, mix well, and if a lot of foam appears, add a few drops of octanol. Heat in a boiling water bath for 2 hours. Remove from the heat, add 1.0 mL of hydroxyammonium hydrochloride solution, let stand for 15-20 minutes, and dilute to 25 mL with water.

[0116] Follow the instrument's operating procedures to adjust the analytical conditions to their optimal state. Determine the lead standard under background absorption subtraction.

[0117] Series, blank, and sample solutions. If the iron content in the sample solution exceeds the lead content by more than 100 times, the deuterium lamp background subtraction method is not suitable; the Zeeman effect background subtraction method should be used instead. Plot a concentration-absorbance standard curve and calculate the sample content.

[0118] Transfer the standard, blank, and sample solutions to evaporating dishes and evaporate to dryness in a water bath. Add 10 mL of hydrochloric acid to dissolve the residue, transfer to a separatory funnel, and extract twice with an equal volume of MIBK, retaining the hydrochloric acid solution. Wash the MIBK layer with 5 mL of hydrochloric acid, combine the hydrochloric acid solutions, remove acid if necessary, and make up to volume. Perform the determination according to the instrument operating procedure. The output function formula for the analytical results is:

[0119]

[0120] In formula (14), ω is the mass fraction of mercury in the sample, in μg / g; ρ1 is the mass concentration of lead in the test solution, in mg / L; ρ0 is the mass concentration of lead in the blank solution, in mg / L; V is the total volume of the sample digest solution, in mL; and m is the sample amount, in g.

[0121] In the above embodiments, the detection method of acetylacetone spectrophotometry is as follows:

[0122] (1) Collect the air gas evaporated from the hair dye device to be tested and prepare a formaldehyde stock solution; (2) Prepare an acetylacetone solution; (3) Dilute the formaldehyde stock solution and transfer it to an evaporating dish, and then place the evaporating dish in a sealed box; (4) React the formaldehyde in the sealed box with the acetylacetone solution in different volumes, and measure the absorbance at the same time; (5) Make a blank control and measure the absorbance.

[0123] The detection method using high performance liquid chromatography is as follows:

[0124] When setting the mobile phase methanol density to 0.03 mol / L, the ammonium acetate flow rate to 1.2 ml / min, the column temperature to 25℃, and the wavelength programs to 0-4.2 min, 238 nm, 5-7.5 min, 405 nm, 7.6-9.35 min, 530 nm; 9.35-9.8 min, 295 nm, 10.1-11.2 min, or 628 nm, benzoic acid, phenylenediamine, lead, or mercury in hair dye are determined. A detection limit of ≤0.3 ng for phenylenediamine is considered acceptable.

[0125] In the above embodiments, the method of combining X-ray diffraction measurement and polarizing microscopy observation is to first perform X-ray diffraction measurement and record the measured data, and then observe the data through a polarizing microscope and record the measured data. The data recorded by the two methods are compared to obtain the detection data of harmful components in hair dye.

[0126] In a specific embodiment, the oil-containing sample or the organically modified sample should be ashed in a high-temperature furnace at 450°C for one hour.

[0127] For coarse-particle samples (d5>0.04mm), grinding is required. The sample should first be sieved, then the residue should be ground, sieved again, and mixed thoroughly. X-ray diffraction measurements use the back-pressure method for slide preparation. The sample frame is placed on a frosted glass plate, the sample is inserted, and it must be pressed vertically with appropriate pressure. The side with the frosted glass is used as the test surface.

[0128] X-ray diffraction measurements are divided into qualitative and quantitative measurements. To ensure measurement accuracy, the technical parameters and measurement conditions of X-ray diffraction should meet the technical requirements of Annex A.

[0129] The qualitative determination method is as follows:

[0130] The X-ray diffraction data of the sample are compared with the X-ray diffraction data of asbestos minerals to identify the type of asbestos in the sample. The K-value method is used for quantitative determination of asbestos by X-ray diffraction. The Ki value of the mineral should be determined before sample testing; the Ki value determination is performed according to Appendix C. The output function formula for the content of a certain asbestos mineral in the sample is:

[0131] In formula (15), X i I represents the content of i asbestos minerals in the sample; i K represents the diffraction peak intensity of type i asbestos mineral; i The reference strength is i for a type of asbestos mineral.

[0132] Three test samples should be prepared using the same method for each sample. If the relative error between the three test results does not exceed 10%, the average value should be taken as the final measurement result. Otherwise, three more samples should be added, and the average value of the six measurement data should be taken as the measurement result of that sample.

[0133] Take three appropriate samples and place them on glass slides respectively. Add an appropriate amount of impregnating oil with a refractive index of 1.550±0.005 using a dropper, ensuring the powder particles are fully dispersed and wetted, avoiding particle overlap and accumulation. Then cover with a coverslip for testing. The testing method is as follows: For samples where X-ray diffraction detects serpentine minerals, observe the three prepared test samples under single-polarized light. If a low-relief fibrous mineral with an aspect ratio greater than 3 is found in one of the samples, the sample is determined to contain serpentine asbestos; otherwise, it is determined not to contain serpentine asbestos. The X-ray diffraction comparison data for serpentine asbestos are as follows:

[0134]

[0135] For samples where X-ray diffraction analysis detected amphibole-like minerals, three prepared test samples were observed under single-polarized light. If a fibrous mineral with a central projection and an aspect ratio greater than 3 was found in one of the samples, it was identified as amphibole-like asbestos; otherwise, it was identified as non-amphibole-like asbestos. The X-ray diffraction comparison data for amphibole-like asbestos are as follows:

[0136]

[0137] If no characteristic diffraction peaks of asbestos minerals appear in the X-ray diffraction results, the sample is determined to be free of asbestos.

[0138] If a characteristic diffraction peak of a certain asbestos mineral appears in the X-ray diffraction results, and the mineral is found to be fibrous under a polarizing microscope, then the sample is determined to contain asbestos; the X-ray diffraction comparison data of the asbestos are as follows:

[0139]

[0140]

[0141] If a certain asbestos mineral diffraction characteristic peak appears in the X-ray diffraction results, but the mineral is not found to be fibrous under a polarizing microscope, then the sample is determined to be free of asbestos.

[0142] In the above embodiments, the evaluation during the detection process is performed using the following methods:

[0143] The hair dye is pumped into the test pipeline by a pressure pump. The transmission of the hair dye liquid in the test pipeline requires the pump station to provide pressure. The pressure is used to overcome the frictional resistance in the test pipeline by calculating the fluid movement of the hair dye using Bernoulli's equation. Since the local frictional resistance is mainly generated when the hair dye liquid flows through the valves and the curved test pipeline, the number of valves and bends in the long test pipeline is small, so the wear is also less.

[0144] The friction function along the test pipe for the hair dye flow rate is:

[0145]

[0146] In formula (1), V represents the velocity of the hair dye fluid in the test pipe, D represents the inner diameter of the test pipe, λ represents the coefficient of the hair dye flow friction, and the value of λ is related to R, the hair dye flow friction; the R function is expressed as:

[0147]

[0148] In formula (2), υ is the kinematic viscosity of the hair dye fluid, Q is the volumetric flow rate of the hair dye fluid, and the frictional loss is converted into pressure loss P as follows:

[0149]

[0150] In formula (3), ρ represents the density of the hair dye liquid. If the local friction between different test pipes is not considered, the internal pressure at a distance L from the test pipe can be calculated:

[0151]

[0152] In formula (4), P o Δz represents the pressure at which the hair dye liquid flows out, and Δz represents the high potential energy difference.

[0153] During the operation of the test pipeline, the internal pressure decreases with increasing distance, reaching its minimum at the starting point and then gradually decreasing. When the levels of heavy metal elements that endanger human health are the same, the first segment of the test pipeline has the greatest impact on the test pipeline, and the impact gradually decreases with increasing distance. Therefore, the risk values ​​differ in each section of the hair dye liquid test pipeline.

[0154] The pressure at the heavy metal element location in the test pipeline is calculated through mechanical analysis, providing a basis for the repair and replacement of the test pipeline for hair dye liquid.

[0155] When the pressure coefficient of the test pipeline for hair dye liquid is expressed as:

[0156] P sw =P f / F s (5)

[0157] In formula (5), P sw F represents the pressure coefficient indicating the safe operation of the test pipeline. s P represents the safety factor. f This represents the failure pressure of the test pipeline at the heavy metal element location. The failure pressure function is:

[0158] P f =P0R s (6)

[0159] In formula (6), P0 is the destructive pressure of the normal test pipeline, and R s The residual strength coefficient of the test pipe for hair dye liquid is related to the test pipe as follows:

[0160]

[0161] In formula (7), L is the length of the test pipe containing hair dye with a content that endangers human health, t is the wall thickness of the test pipe, D is the outer diameter of the test pipe, and d is the depth of the test pipe containing hair dye with a content that endangers human health.

[0162] The formula for calculating the internal pressure that a test pipeline carrying a liquid hair dye that poses a chemical hazard to human health can withstand is as follows:

[0163]

[0164] In formula (8), p represents the internal σ that the test pipeline can withstand. Ts Let Q be the tensile strength of the test pipe material, and Q be the correction factor for the length of the test pipe. The correction factor function is expressed as:

[0165]

[0166] When a test pipeline for hair dye liquid contains chemicals that may endanger human health, the formula for calculating the maximum safe operating pressure of the test pipeline is as follows:

[0167]

[0168] In formula (10), M is the expansion coefficient of the hair dye liquid test pipe under heating state, F is the design pressure bearing coefficient of the hair dye liquid test pipe, d is the depth of hair dye flow in the test pipe, and t is the wall thickness of the test pipe.

[0169] 4 Experimental Samples

[0170]

[0171] This invention's embedded test pipeline detection method detects the highest number of heavy metal elements in test pipeline sample data with the highest detection accuracy. In 500 test samples, this invention detected 138 hydrogen peroxide heavy metal elements, 42 lead heavy metal elements, and a total of 180 mercury heavy metal elements. The number of mercury heavy metal elements is greater than the number of p-phenylenediamine elements.

[0172] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these specific embodiments are merely illustrative. Those skilled in the art can omit, substitute, and modify the details of the above methods and systems in various ways without departing from the principles and essence of the present invention. For example, combining the above method steps to perform substantially the same function in substantially the same way to achieve substantially the same result falls within the scope of the present invention. Therefore, the scope of the present invention is defined only by the appended claims.

Claims

1. A hair dye harmful chemical substance detection system characterized by The detection system includes: Terminal controller, A / D conversion module, microcontroller control system, flow controller, control chip, gas detection unit, heating temperature setting module, adjustment module, instrumentation amplifier, relay switch, heating furnace, tubular SOFC monitor, control chip, flow controller, temperature sensor, pressure sensor, gas valve, gas detection unit, heating temperature setting module, interface display module, data interaction module and mobile terminal; The temperature sensor, pressure sensor, and gas valve are connected to the flow controller, which in turn is connected to the control chip. The control chip is connected to the gas detection unit, the heating temperature setting module, and the interface display module, respectively. The control chip is also connected to the data interaction module, which is connected to the mobile terminal. The tubular SOFC monitor is connected to the heating furnace, which is connected to a relay switch. The relay switch is connected to the terminal controller via a microcontroller control system. The instrumentation amplifier displays the temperature status of the heating furnace. The detection system operates as follows: The hair dye sample to be tested is input into the test pipeline. Under the control of the gas valve, the pressure sensor senses the pressure data in the test pipeline, and the temperature sensor senses the temperature data in the test pipeline. The control chip controls the working status of the flow controller. The control chip interacts with the mobile terminal through the data interaction module. The control chip also controls the working status of the gas detection unit, the heating temperature setting module, and the interface display module. The tubular SOFC monitor is used to detect the hair dye data in the test pipeline. The flow information is obtained through the adjustment module, and the flow detection status is controlled or detected by the terminal controller. The detection process is evaluated using Bernoulli's equation. The gas detection unit detects the composition of the steam gas of the hair dye when it is heated. Data information is exchanged between the terminal controller and the mobile terminal.

2. A method for detecting harmful ingredients of a plant nourishing type hair dye, characterized by: The detection method includes the following steps: Step 1: The hair dye to be tested is fed into the test pipeline as a hair dye fluid. The target colorant, obtained by mixing black, yellow, red, and blue colorants in proportion according to the target color, is chemically extracted. The flow rate, temperature, and pressure in the test pipeline are sensed by a flow controller, temperature sensor, and pressure sensor, respectively. The dye is tested in either liquid or gaseous state, and the composition of the hair dye or gaseous components is detected. The extraction methods include hydride atomic fluorescence spectrometry, mercury analysis, or cold vapor atomic absorption spectrometry. Step 2: Extract the chemical substances from the mixed target colorant and dyeing base paste; detect the lead content using graphite furnace atomic absorption spectrophotometry or flame atomic absorption spectrophotometry. Step 3: Keep your hair clean and use a comb to apply the hair dye evenly from the roots; use hydride atomic fluorescence spectrometry to detect the arsenic content in the clean hair. Step 4: Wrap your hair in a damp towel at room temperature for one hour and then rinse it clean, or wrap your hair in a heated cap for thirty-five minutes and then rinse it clean; detect the formaldehyde content by acetylacetone spectrophotometry or high performance liquid chromatography. Step 5: After rinsing, keep the hair at 50% humidity and test the hair at 50% humidity. The content of asbestos from hair dye remaining in the hair after washing is detected by a combination of X-ray diffraction and polarized light microscopy.

3. The method for detecting harmful ingredients of a plant nourishing type hair dye according to claim 2, characterized by: The working method of hydride atomic fluorescence spectrometry is as follows: Prepare standard solutions III: 0 mL, 0.50 mL, 1.25 mL, 2.50 mL, and 5.00 mL are placed in 25 mL stoppered colorimetric tubes. Add 2.5 mL of hydrochloric acid and dilute with water to the mark to obtain a series of mercury standard solutions with corresponding concentrations of 0 μg / L, 0.20 μg / L, 0.50 μg / L, 1.00 μg / L, and 2.00 μg / L. Weigh 0.5 g to 1 g of sample into a cleaned polytetrafluoroethylene sample dissolving cup. First, place the sample in a temperature-adjustable 100℃ constant temperature electric heater or water bath to evaporate the mercury. Then, irradiate the sample with a mercury hollow cathode lamp. The intensity of the irradiation is directly proportional to the mercury content. Quantify the sample by comparing it with the standard series. The working method of the mercury analyzer is as follows: it detects the concentration of gaseous active mercury and particulate mercury in a gaseous state, and realizes high-resolution online continuous observation of ultra-trace mercury in the air of hair dye. When the detection range is 0.1-10000ng / m3, the minimum detection limit of mercury is <0.1ng / m3. The working method of cold atomic absorption spectrometry is as follows: taking advantage of the different boiling points of the components in a mixed liquid or liquid-solid system, the low-boiling-point component is evaporated and then condensed to separate the entire component. Air or nitrogen is introduced at room temperature to vaporize metallic mercury, which is then loaded into a cold atomic absorption mercury analyzer to absorb ultraviolet light at 253.7 nm generated by a mercury lamp. Within a certain concentration range, the mercury concentration and absorbance have a linear relationship. The mercury content in the sample is determined using the standard curve method.

4. The method for detecting harmful components in a plant-based nourishing hair dye according to claim 2, characterized in that: The working method of graphite furnace atomic absorption spectrophotometry is as follows: Samples of hair dyeing equipment were collected using a glass fiber filter cartridge and prepared into a sample solution through dry ashing digestion or wet digestion. Beryllium was atomized in a graphite tube at high temperature and absorbed the characteristic spectral line 234.9 nm emitted from a beryllium hollow cathode lamp in the optical path. The intensity of the characteristic spectral line was determined by atomic absorption spectrophotometry based on the change in intensity of the characteristic spectral line. The working method of flame atomic absorption spectrophotometry is as follows: The lead in the air of hair dye gas environment was determined. When the detection limit was 0.5 μg / m, when the sampling volume was 50 m 3 The minimum detection concentration was 5×10 -4 mg / m 3 When the lead content was considered to be overproof.

5. The method for detecting harmful components in a plant-based nourishing hair dye according to claim 2, characterized in that: The spectrophotometric detection method for acetylacetone is as follows: (1) Collect the air gas evaporated from the hair dye device to be tested and prepare a formaldehyde stock solution; (2) Prepare an acetylacetone solution; (3) Dilute the formaldehyde stock solution and transfer it to an evaporating dish, and then place the evaporating dish in a sealed box; (4) React the formaldehyde in the sealed box with the acetylacetone solution in different volumes, and measure the absorbance at the same time; (5) Make a blank control and measure the absorbance. The detection method using high performance liquid chromatography is as follows: When setting the mobile phase methanol density to 0.03 mol / L, the ammonium acetate flow rate to 1.2 ml / min, the column temperature to 25℃, and the wavelength programs to 0-4.2 min, 238 nm, 5-7.5 min, 405 nm, 7.6-9.35 min, 530 nm; 9.35-9.8 min, 295 nm, 10.1-11.2 min, or 628 nm, benzoic acid, phenylenediamine, lead, or mercury in hair dye are determined. A detection limit of ≤0.3 ng for phenylenediamine is considered acceptable.

6. The method for detecting harmful components in a plant-based nourishing hair dye according to claim 2, characterized in that: The method combines X-ray diffraction measurement with polarizing microscopy observation. First, X-ray diffraction measurement is performed and the measured data is recorded. Then, observation is conducted using a polarizing microscope and the measured data is recorded. The data from both methods are compared to obtain the final detection data for harmful components in hair dye.

7. The method for detecting harmful ingredients of a plant nourishing type hair dye according to claim 2, characterized by: The process of constructing and applying Bernoulli's equation is as follows: The friction function along the test pipe for the hair dye flow rate is: In formula (1), V represents the velocity of the hair dye fluid in the test pipe, D represents the inner diameter of the test pipe, λ represents the coefficient of the hair dye flow friction, and the value of λ is related to R, the hair dye flow friction; the R function is expressed as: In formula (2), υ is the kinematic viscosity of the hair dye fluid, Q is the volumetric flow rate of the hair dye fluid, and the frictional loss is converted into pressure loss P as follows: In formula (3), ρ represents the density of the hair dye liquid. The internal pressure at a distance L from the test pipe is calculated as follows: In Equation (4), P o represents the pressure of the hair dye liquid flow, and Δz represents the potential energy of the height difference. The pressure coefficient of the liquid hair dye test pipeline is expressed as: P sw = P f / F s (5) In formula (5), P sw F represents the pressure coefficient indicating the safe operation of the test pipeline. s P represents the safety factor. f This represents the failure pressure of the test pipeline at the heavy metal element location. The failure pressure function is: P f <P0R s (6) In formula (6), P0 is the failure pressure of the normal test pipeline, R s is the residual strength coefficient of the hair dye liquid test pipeline, and the relationship with the test pipeline is: In formula (7), L is the length of the test pipe containing hair dye with a content that endangers human health, t is the wall thickness of the test pipe, D is the outer diameter of the test pipe, and d is the depth of the test pipe containing hair dye with a content that endangers human health. The formula for calculating the internal pressure that hair dye content can withstand, which endangers human health, is as follows: In Equation (8), p represents the internal σ Ts is the tensile strength of the test pipe material, and Q is a correction factor for the length of the test pipe. The correction factor function is represented as: In formula (9), when there are chemicals that endanger human health in the test pipeline for hair dye liquid, the formula for calculating the maximum safe operating pressure of the test pipeline is: In formula (10), M is the expansion coefficient of the hair dye liquid test pipe under heating state, F is the design pressure bearing coefficient of the hair dye liquid test pipe, d is the depth of hair dye flow in the test pipe, and t is the wall thickness of the test pipe.

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