A method for detecting the color absorption rate during the process of mixing and dyeing with reactive dyes

Abstract

The present invention relates to a method for detecting the color absorption rate during the process of dyeing with a mixture of reactive dyes. During the process of dyeing with two or more reactive dyes, a dye liquor sample is taken at time t, the pH value is adjusted to neutral and diluted, and then detected by the CE-UV method. The peak area of the substance peak of the target substance in the dye liquor sample is measured, and the concentration of the target substance in the dye liquor corresponding to time t during the dyeing process is obtained through calculation. Furthermore, the color absorption rate of each reactive dye corresponding to time t during the dyeing process is obtained. The target substance is a reactive dye or a hydrolysis product of a reactive dye. The peak position of the target substance is determined by the standard addition method. The formula used for calculation is a linear equation, which is obtained by performing CE-UV detection on target substances with different concentrations to obtain an electrophoresis spectrum, and then performing linear fitting on the peak areas of the target substances in the electrophoresis spectrum and the corresponding concentrations. The method of the present invention is simple and can accurately detect the color absorption rate during the process of dyeing with a mixture of reactive dyes.

Description

Technical Field

[0001] The present invention belongs to the technical field of dye concentration detection, and relates to a method for detecting the color absorption rate during the process of dyeing with reactive dyes in a mixture of different reactive dyes. Background Art

[0002] In recent years, with the continuous development of the textile industry, although the cellulose dyeing with reactive dyes has become increasingly perfect, in order to obtain products with excellent performance and cost savings, the multi-component dyeing technology has attracted wide attention. Due to technical limitations, the current research on the dyeing mechanism of multi-component reactive dyes is not perfect enough. When using multi-component reactive dyes for dyeing, the dye utilization rate of each reactive dye and the fabric during the adsorption stage and the fixation stage is different from that in single-dye dyeing. There are also certain differences in the phase distribution and mass transfer phenomena of different reactive dyes during the dyeing process. In addition, the interaction between reactive dyes also has a certain impact on the dyeing of reactive dyes. Therefore, accurately grasping the concentration change of each reactive dye during the dyeing process is of decisive significance for improving the textile dyeing process level with a mixture of different reactive dyes.

[0003] The ultraviolet-visible spectrophotometer monitors the change in the concentration of reactive dyes by measuring the change in the absorbance of the solution. For the determination of multi-component dyes, it is necessary to use mathematical techniques to calculate the dye concentration. For example, in Document 1 (Determination of dyes in eosin ink by dual-wavelength spectrophotometry [J]. Chinese Journal of Analytical Chemistry, 1995, 23(4): 490-490.), for reactive dyes with severely overlapping absorption curves, the ultraviolet-visible spectrophotometer method cannot perform accurate calculations. Raman spectroscopy qualitatively and quantitatively analyzes reactive dyes by measuring the change in the intensity of characteristic peaks of monochlorotriazine and vinyl sulfone type reactive dyes. For example, in Document 2 (Real-time monitoring of multicomponent reactive dye adsorption on cotton fabrics by Raman spectroscopy [J]. Spectrochim Acta Part A: Mol Biomol Spectrosc, 2020, 230: 118051.), this method cannot be used for accurate qualitative and quantitative analysis of multi-component solutions with highly overlapping Raman peaks. Summary of the Invention

[0004] The object of the present invention is to solve the problems existing in the prior art and provide a method for detecting the color absorption rate during the process of dyeing with reactive dyes in a mixture of different reactive dyes.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for detecting the dye uptake rate during the process of mixing reactive dyes for dyeing. During the process of dyeing with two or more reactive dyes, a dye liquor sample is taken at time t. After adjusting the pH value to neutral and diluting it, the CE-UV method (CE is the abbreviation of Capillary Electrophoresis, UV is the abbreviation of Ultraviolet, and the CE-UV method refers to the method of capillary electrophoresis combined with ultraviolet detection) is used for detection. The peak area of the substance peak of the target in the dye liquor sample is measured, and the concentration of the target in the dye liquor corresponding to time t during the dyeing process is obtained through calculation. Furthermore, the dye uptake rate of each reactive dye corresponding to time t during the dyeing process is obtained;

[0007] Time t is any one or more moments during the dyeing process;

[0008] Since the reactive dye starts to hydrolyze after adding alkali, if neutralization is not carried out after sampling, the hydrolysis process will continue under alkaline conditions, which will cause the data obtained from the test not to truly represent the sampled dye liquor sample and the results will be inaccurate. Therefore, it is necessary to adjust the pH value of the dye liquor sample to neutral to terminate the hydrolysis;

[0009] There is a linear relationship between the peak area and concentration of the target, and there is a linear range of the calibration curve. The purpose of dilution is to adjust the concentration of the target to the linear range so that quantitative calculation using a linear equation can be more accurate; specific dilution basis: Calculate the concentration of the solution taken according to the stock solution and dilute it to the upper limit of the linear range for determination;

[0010] The target is a reactive dye or a hydrolysis product of a reactive dye;

[0011] The elution position (i.e., migration time) of the target is determined by the standard addition method; in previous studies on reactive dyes and their hydrolysis products, the inventors determined the elution positions of the targets one by one. Therefore, when separating the mixed dye liquor by CE, it is possible to qualitatively analyze according to the migration time and quantitatively analyze according to the peak area;

[0012] The formula used for calculation is a linear equation, which is obtained by performing CE-UV detection on targets with different concentrations to obtain an electrophoretic spectrum, and then performing linear fitting on the peak areas of the targets in the electrophoretic spectrum and their corresponding concentrations;

[0013] The calculation formula for the dye uptake rate of any reactive dye X corresponding to time t during the dyeing process is as follows:

[0014]

[0015] In the formula, C0 is the concentration of reactive dye X in the dye liquor at the start of dyeing; C t总 is the sum of the concentrations of reactive dye X and its hydrolysis product in the dye liquor corresponding to time t during the dyeing process.

[0016] Capillary electrophoresis separation conditions include, on the one hand, the setting of instrument parameters, such as injection conditions, separation voltage, detection wavelength, and the length and inner diameter of the capillary used; on the other hand, it is the background electrolyte (BGE) used when separating the target substance. These separation conditions need to be optimized according to the target substance in the early stage to obtain the best separation degree and sensitivity; in the present invention, an H3BO3 solution is used to adjust the pH value of the BGE during CE separation. The BGE used in CE separation is generally a buffer system, so in fact, a sodium borate-boric acid buffer system is adopted here, so that the BGE can maintain the stability of its pH during multiple uses, thus ensuring the reproducibility of the separation.

[0017] In CE separation, the BGE plays an important role. It not only conducts electricity in the solution, but also may interact with the target substance to obtain better separation degree and sensitivity. Therefore, in the experiment, the concentration of Na2B4O7·10H2O, the type and concentration of organic additives, and the pH value are optimized to obtain the optimal conditions for separating each dye. If such selection is not made, it cannot be ensured that each target substance can be completely separated.

[0018] For different reactive dyes, the formulation of the BGE used when separating the target substance is not completely the same.

[0019] As a preferred technical solution:

[0020] A method for detecting the color absorption rate during the process of reactive dye combination dyeing as described above, where two or more reactive dyes are reactive red 195, reactive yellow 145, and reactive blue 194.

[0021] A method for detecting the color absorption rate during the process of reactive dye combination dyeing as described above. When using the CE-UV method for detection, the background electrolyte used when separating the target substance uses Na2B4O7·10H2O as the buffer substance, acetonitrile as the additive, and at the same time, an H3BO3 solution is used to adjust the pH value.

[0022] A method for detecting the color absorption rate during the process of reactive dye combination dyeing as described above. The concentration of Na2B4O7·10H2O in the background electrolyte used when separating the target substance is 10.0 mmol / L, the volume concentration of acetonitrile is 15%, and the pH value is 8.5.

[0023] A method for detecting the color absorption rate during the process of reactive dye combination dyeing as described above, where two or more reactive dyes are reactive black 5, reactive red 195, and reactive blue 19.

[0024] A method for detecting the color uptake rate during the process of reactive dye combination dyeing. When using the CE-UV method for detection, the background electrolyte used for separating the target substance uses Na2B4O7·10H2O as a buffering substance, acetonitrile and α-CD together as additives, and at the same time uses H3BO3 solution to adjust the pH.

[0025] A method for detecting the color uptake rate during the process of reactive dye combination dyeing as described above. In the background electrolyte used for separating the target substance, the concentration of Na2B4O7·10H2O is 20.0 mmol / L, the volume concentration of acetonitrile is 15%, the concentration of α-CD is 20.0 mmol / L, and the pH value is 9.

[0026] Beneficial effects

[0027] The method for detecting the color uptake rate during the process of reactive dye combination dyeing of the present invention uses capillary electrophoresis technology for the first time to quantitatively analyze reactive dyes and their hydrolysis products during the single-dyeing and combination-dyeing processes of reactive dyes, provides technical support for the optimization of subsequent dyeing processes, and solves the problem that the prior art cannot accurately detect the color uptake rate during the process of reactive dye combination dyeing. Description of the drawings

[0028] Figure 1 It is the dyeing flow chart of Example 1;

[0029] Figure 2 It is for Reactive Red 195 according to Figure 1 The capillary electrophoresis spectrogram measured when dyeing a single-dye sample; the color uptake rate of the reactive dye gradually increases with the increase of time. After adding anhydrous sodium carbonate, the reactive dye begins to hydrolyze and is converted into various levels of hydrolysis products. Among them, peak 1 represents HES-HES-red-195, peak 2 represents VS-Cl-red-195, peak 3 represents SES-Cl-red-195, and peak * represents other hydrolysis products;

[0030] Figure 3 It is for Reactive Red 195 according to Figure 1 The color uptake rate curve diagram obtained by two methods of CE-UV and UV-Vis when dyeing a single-dye sample;

[0031] Figure 4 It is for Reactive Yellow 145 according to Figure 1 The capillary electrophoresis spectrogram measured when dyeing a single-dye sample; the color uptake rate of the reactive dye gradually increases with the increase of time. After adding anhydrous sodium carbonate, the reactive dye begins to hydrolyze and is converted into various levels of hydrolysis products. Among them, peak 1 represents VS-Cl-yellow-145, peak 2 represents SES-Cl-yellow-145, peak 3 represents HES-HES-yellow-145, and peak * represents other hydrolysis products;

[0032] Figure 5 The absorption rate curve graphs obtained by two methods, CE-UV and UV-Vis, when the sample is dyed with reactive yellow 145 solution Figure 1 ;

[0033] Figure 6 The capillary electrophoresis spectrum graph measured when the sample is dyed with reactive blue 194 Figure 1 ; The absorption rate of the reactive dye gradually increases with the increase of time. After adding anhydrous sodium carbonate, the reactive dye begins to hydrolyze and is converted into various hydrolysis products. Among them, peak 1 represents VS-Cl-blue-194, peak 2 represents SES-Cl-blue-194, and peak * represents other hydrolysis products

[0034] Figure 7 The absorption rate curve graphs obtained by two methods, CE-UV and UV-Vis, when the sample is dyed with reactive blue 194 solution Figure 1 ;

[0035] Figure 8 The dyeing flow chart of Example 2

[0036] Figure 9 The capillary electrophoresis spectrum graph measured when the sample is dyed with reactive black 5 Figure 8 ; The absorption rate of the reactive dye gradually increases with the increase of time. After adding anhydrous sodium carbonate, the reactive dye begins to hydrolyze and is converted into various hydrolysis products. Among them, peak 4 represents HES-HES-black-5, peak 5 represents VS-VS-black-5, and peak 6 represents SES-SES-black-5

[0037] Figure 10 The absorption rate curve graphs obtained by two methods, CE-UV and UV-Vis, when the sample is dyed with reactive black 5 solution Figure 1 ;

[0038] Figure 11 The capillary electrophoresis spectrum graph measured when the sample is dyed with reactive blue 19 Figure 8 ; The absorption rate of the reactive dye gradually increases with the increase of time. After adding anhydrous sodium carbonate, the reactive dye begins to hydrolyze and is converted into various hydrolysis products. Among them, peak 1 represents HES-blue-19, peak 2 represents VS-blue-19, and peak 3 represents SES-blue-19

[0039] Figure 12 The absorption rate curve graphs obtained by two methods, CE-UV and UV-Vis, when the sample is dyed with reactive blue 19 solution Figure 1 ;

[0040] Figure 13 For reactive red 195Figure 8 Capillary electrophoresis spectrogram measured for a single-dyed sample; the exhaustion rate of the reactive dye gradually increases with time. After adding anhydrous sodium carbonate, the reactive dye starts to hydrolyze and is converted into various hydrolysis products. Among them, peak 7 represents HES-HES-red-195, peak 8 represents VS-Cl-red-195, and peak 9 represents SES-Cl-red-195;

[0041] Figure 14 For reactive red 195 according to Figure 8 According to Figure 1 Exhaustion rate curve graphs obtained by two methods, CE-UV and UV-Vis, for a single-dyed sample. Detailed implementation manners

[0042] The present invention will be further described below in conjunction with specific implementation manners. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0043] Example 1

[0044] A method for detecting the exhaustion rate during the process of mixing and dyeing with reactive dyes, the steps are as follows:

[0045] (1) Select reactive dyes and determine the hydrolysis products of the reactive dyes;

[0046] There are three reactive dyes, namely reactive red 195, reactive yellow 145 or reactive blue 194;

[0047] There are two types of hydrolysis products: vinyl sulfone type hydrolysis products and completely hydrolyzed products;

[0048] (2) Determine the peak positions and peak area-concentration linear equations of each reactive dye and its hydrolysis products;

[0049] The determination process of the peak positions and peak area-concentration linear equations of reactive dye X (reactive red 195, reactive yellow 145 or reactive blue 194) is as follows: Prepare dye solutions with concentrations of 1 mg / L, 5 mg / L, 10 mg / L, 20 mg / L, 30 mg / L, 40 mg / L, and 50 mg / L of reactive dye X respectively, and use the CE-UV method to detect the dye solutions with different concentrations respectively to determine the peak positions of reactive dye X, calculate the peak areas, and perform linear fitting based on different peak areas and corresponding concentrations to obtain the peak area-concentration linear equations;

[0050] The process of obtaining the peak positions and peak area-concentration linear equations of the vinyl sulfone type hydrolysis products of reactive dye X (reactive red 195, reactive yellow 145 or reactive blue 194) is basically the same as that of reactive dye X, except that the solute in the dye solution is the vinyl sulfone type hydrolysis product of reactive dye X; among them, the preparation method of the vinyl sulfone type hydrolysis product of reactive dye X is: take 0.1 g of reactive dye X and add it to 25 mL of NaOH solution with a concentration of 0.16 g / L, dissolve it at room temperature for 20 minutes, and neutralize it to pH = 7.0 with 1 mol / L hydrochloric acid solution to obtain the vinyl sulfone type hydrolysis product;

[0051] The process of obtaining the peak positions and peak area-concentration linear equations of the complete hydrolysis products of reactive dye X (reactive red 195, reactive yellow 145 or reactive blue 194) is basically the same as that of reactive dye X, except that the solute in the dye solution is the complete hydrolysis product of reactive dye X; the preparation method of the complete hydrolysis product of reactive dye X is: take 0.25 g of reactive dye X and add it to 50 ml of NaOH solution with a concentration of 0.1 mol / L, heat it to 60 °C and keep it at a constant temperature for 3.5 h, cool it to room temperature, and then neutralize it to pH = 7.0 with 1 moI / L hydrochloric acid solution to obtain the complete hydrolysis product;

[0052] When using the CE-UV method for detection, the background electrolyte used for separating the target substances uses Na2B4O7·10H2O with a concentration of 10.0 mmol / L as the buffer substance, acetonitrile with a volume concentration of 15% as the additive, and at the same time use H3BO3 solution to adjust the pH value to 8.5;

[0053] In step (2), the peak positions of 9 substances and the peak area-concentration linear equations of 9 substances are obtained. These 9 substances are reactive red 195, reactive yellow 145, reactive blue 194, the vinyl sulfone type hydrolysis product of reactive red 195, the vinyl sulfone type hydrolysis product of reactive yellow 145, the vinyl sulfone type hydrolysis product of reactive blue 194, the complete hydrolysis product of reactive red 195, the complete hydrolysis product of reactive yellow 145, and the complete hydrolysis product of reactive blue 194;

[0054] (3) Determine the dyeing process flow;

[0055] The dyeing process is as Figure 1 shown, specifically as follows:

[0056] Prepare the original dye solution (composed of dye and deionized water) with a total dye concentration of 5000 mg / L in a conical flask, among which, the mass ratio of reactive red 195, reactive yellow 145, and reactive blue 194 is 1:1:1;

[0057] Place the conical flask in a shaking water bath, set the initial temperature of the shaking water bath to 30 °C, add 10.0 g of cotton fabric to the conical flask, control the liquor ratio to 10:1, seal the bottle mouth with plastic wrap and start dyeing;

[0058] When the dyeing lasts for 10 min, add 2.0 g of sodium sulfate to the conical flask. When the dyeing lasts for 20 min, add another 2.0 g of sodium sulfate to the conical flask. When the dyeing lasts for 30 min, control the shaking water bath to heat up to 60 °C at a heating rate of 9.9 °C / min, then stop heating and add 0.75 g of anhydrous sodium carbonate to the conical flask. When the dyeing lasts for 40 min, add another 0.75 g of anhydrous sodium carbonate to the conical flask. When the dyeing lasts for 60 mins, end the dyeing;

[0059] (4) Sampling and testing;

[0060] Immediately after the start of dyeing, take a 1 mL sample of the dye liquor once, and then take a 1 mL sample of the dye liquor every 10 min during the dyeing process. Adjust the pH value of the dye liquor sample to neutral with 0.5 mol / L HCl solution and dilute it by a certain multiple;

[0061] The dye liquor sample is detected by the CE-UV method. Measure the peak area of the substance peak of reactive dye X and substitute it into the corresponding peak area-concentration linear equation to obtain the concentration of reactive dye X in the dye liquor corresponding to each sampling time. Measure the peak area of the substance peak of the vinyl sulfone type hydrolysis product of reactive dye X and substitute it into the corresponding peak area-concentration linear equation to obtain the concentration of the vinyl sulfone type hydrolysis product of reactive dye X in the dye liquor corresponding to each sampling time. Measure the peak area of the substance peak of the complete hydrolysis product of reactive dye X and substitute it into the corresponding peak area-concentration linear equation to obtain the concentration of the complete hydrolysis product of reactive dye X in the dye liquor corresponding to each sampling time;

[0062] When using the CE-UV method for detection, the background electrolyte used for separating the target substances uses Na2B4O7·10H2O with a concentration of 10.0 mmol / L as the buffer substance, acetonitrile with a volume concentration of 15% as the additive, and adjust the pH value to 8.5 with H3BO3 solution;

[0063] Step (4) obtains the concentrations of 9 substances in the dye liquor corresponding to each sampling time. These 9 substances are respectively reactive red 195, reactive yellow 145, reactive blue 194, the vinyl sulfone type hydrolysis product of reactive red 195, the vinyl sulfone type hydrolysis product of reactive yellow 145, the vinyl sulfone type hydrolysis product of reactive blue 194, the complete hydrolysis product of reactive red 195, the complete hydrolysis product of reactive yellow 145, and the complete hydrolysis product of reactive blue 194;

[0064] (5) Calculate the color uptake rate of reactive dye X at each sampling time during the actual dyeing process. The calculation formula is as follows:

[0065]

[0066] In the formula, C0 is the concentration of reactive dye X in the dye liquor at the start of dyeing; C t总 is the sum of the concentration of reactive dye X, the concentration of the vinyl sulfone type hydrolysis product of reactive dye X, and the concentration of the completely hydrolyzed product of reactive dye X in the dye liquor corresponding to the time t (each sampling time) during the dyeing process;

[0067] In step (5), the color uptake rates of the three reactive dyes in the dye liquor corresponding to each sampling time are obtained. The results are shown in the following table:

[0068]

[0069]

[0070] In the table, SES-Cl-red-195 represents Reactive Red 195, VS-Cl-red-195 represents the vinyl sulfone type hydrolysis product of Reactive Red 195, HES-HES-red-195 represents the completely hydrolyzed product of Reactive Red 195, SES-Cl-yellow-145 represents Reactive Yellow 145, VS-Cl-yellow-145 represents the vinyl sulfone type hydrolysis product of Reactive Yellow 145, HES-HES-yellow-145 represents the completely hydrolyzed product of Reactive Yellow 145, SES-Cl-blue-194 represents Reactive Blue 194, VS-Cl-blue-194 represents the vinyl sulfone type hydrolysis product of Reactive Blue 194, HES-HES-blue-194 represents the completely hydrolyzed product of Reactive Blue 194, C * represents concentration.

[0071] To verify the accuracy of the method of the present invention, one more dye liquor sample is taken each time in step (4); the dye liquor sample is 1 mL; the pH value of the dye liquor sample is adjusted to neutral with 0.5 mol / L HCl solution and diluted by a certain multiple; the absorbance of the dye liquor sample is detected by the UV-Vis method. Assuming that the dye liquor sample is still a true solution and conforms to the additivity of light, calculate the concentration of reactive dye X in the dye liquor sample at each sampling time during the actual dyeing process according to the following formula:

[0072] A1 = K SES-Cl-red-195 bC SES-Cl-red-195 + K SES-Cl-yellow-145 bC SES-Cl-yellow-145 + K SES-Cl-blue- 194 bC SES-Cl-blue-194 ;

[0073] A2 = K SES-Cl-red-195 bC SES-Cl-red-195 + K SES-Cl-yellow-145 bC SES-Cl-yellow-145 + K SES-Cl-blue- 194 bC SES-Cl-blue-194 ;

[0074] A3 = K SES-Cl-red-195 bC SES-Cl-red-195 + K SES-Cl-yellow-145 bC SES-Cl-yellow-145 + K SES-Cl-blue- 194 bC SES-Cl-blue-194 ;

[0075] In the formula, A1 is the absorbance of the dye solution sample measured at a wavelength of 400 nm; A2 is the absorbance of the dye solution sample measured at a wavelength of 500 nm; A3 is the absorbance of the dye solution sample measured at a wavelength of 600 nm; K * represents the extinction coefficient (when C * is the mass concentration), and A (absorbance) is obtained by using pure solutions of each reactive dye with known concentrations at different wavelengths through an ultraviolet-visible spectrophotometer, and then K is obtained * ; b represents the solution thickness, that is, the optical path;

[0076] The exhaustion rate of each of the 3 reactive dyes in the dye solution corresponding to each sampling time is calculated from the concentration of reactive dye X in the dye solution sample at each sampling time during the actual dyeing process. The results are shown in the following table.

[0077]

[0078]

[0079] In addition, the present invention also detects the exhaustion rate during the single-dyeing process of reactive dyes with reference to the above method. The basic process is the same as above, except that only one reactive dye is selected when preparing the dye solution, that is, reactive red 195, reactive yellow 145 or reactive blue 194. The test results are as Figures 2 to 7 shown.

[0080] Example 2

[0081] A method for detecting the exhaustion rate during the process of mixing reactive dyes for dyeing, the steps are as follows:

[0082] (1) Select reactive dyes and determine the hydrolysis products of the reactive dyes;

[0083] There are three reactive dyes, namely reactive black 5, reactive red 195 or reactive blue 19;

[0084] There are two hydrolysis products: vinyl sulfone type hydrolysis product, complete hydrolysis product;

[0085] (2) Determine the peak positions and peak area-concentration linear equations of each reactive dye and its hydrolysis products;

[0086] The process for determining the peak positions and peak area-concentration linear equations of reactive dye X (reactive black 5, reactive red 195 or reactive blue 19) is as follows: Prepare dye solutions of reactive dye X with concentrations of 5 mg / L, 10 mg / L, 40 mg / L, 80 mg / L, 120 mg / L, and 140 mg / L respectively. Use the CE-UV method to detect the dye solutions with different concentrations respectively, determine the peak positions of reactive dye X, calculate the peak areas, and perform linear fitting based on the different peak areas and corresponding concentrations to obtain the peak area-concentration linear equation;

[0087] The process for obtaining the peak positions and peak area-concentration linear equations of the vinyl sulfone type hydrolysis products of reactive dye X (reactive black 5, reactive red 195 or reactive blue 19) is basically the same as that of reactive dye X, except that the solute in the dye solution is the vinyl sulfone type hydrolysis product of reactive dye X; among them, the preparation method of the vinyl sulfone type hydrolysis product of reactive dye X is: Take 15.0 mg of reactive dye X and dissolve it in 2.0 mL of NaOH solution with a concentration of 0.01 mol / L. After reacting at room temperature for 2 h, neutralize it to pH = 7.0 with 1 mol / L hydrochloric acid solution to obtain the vinyl sulfone type hydrolysis product;

[0088] The process for obtaining the peak positions and peak area-concentration linear equations of the complete hydrolysis products of reactive dye X (reactive black 5, reactive red 195 or reactive blue 19) is basically the same as that of reactive dye X, except that the solute in the dye solution is the complete hydrolysis product of reactive dye X; the preparation method of the complete hydrolysis product of reactive dye X is: Take 0.25 g of reactive dye X and dissolve it in 50.0 mL of NaOH solution with a concentration of 0.1 mol / L. After reacting in a 60 °C water bath for 1.0 h, neutralize it to pH = 7.0 with 0.1 mol / L hydrochloric acid solution to obtain the complete hydrolysis product;

[0089] When using the CE-UV method for detection, the background electrolyte used for separating the target substances uses Na2B4O7·10H2O with a concentration of 20.0 mmol / L as the buffer substance, uses acetonitrile with a volume concentration of 15% and α-CD with a concentration of 20.0 mmol / L as additives together, and adjusts the pH value to 9 with H3BO3 solution at the same time;

[0090] In step (2), the elution positions of 9 substances and the linear equations of peak area - concentration for the 9 substances were obtained. The 9 substances are Reactive Red 195, Reactive Black 5, Reactive Blue 19, the vinylsulfone - type hydrolysis product of Reactive Red 195, the vinylsulfone - type hydrolysis product of Reactive Black 5, the vinylsulfone - type hydrolysis product of Reactive Blue 19, the complete hydrolysis product of Reactive Red 195, the complete hydrolysis product of Reactive Black 5, and the complete hydrolysis product of Reactive Blue 19;

[0091] (3) Determine the dyeing process flow;

[0092] The dyeing process is as Figure 8 shown as follows:

[0093] Prepare an original dye solution with a total dye concentration of 1000 mg / L in a conical flask (composed of dyes and deionized water). Among them, the mass ratio of Reactive Red 195, Reactive Black 5, and Reactive Blue 19 is 1:1:1;

[0094] Place the conical flask in an oscillating water bath, set the initial temperature of the oscillating water bath to 30 °C, add 5.0 g of cotton fabric and 4.0 g of sodium sulfate to the conical flask, control the liquor ratio to 20:1, seal the bottle mouth with plastic wrap, and then start dyeing;

[0095] When the dyeing lasts for 30 min, control the oscillating water bath to heat up to 60 °C at a heating rate of 9.9 °C / min, then stop heating and add 0.75 g of anhydrous sodium carbonate to the conical flask. When the dyeing lasts for 40 min, add another 0.75 g of anhydrous sodium carbonate to the conical flask. End the dyeing when the dyeing lasts for 60 min;

[0096] (4) Sampling and testing;

[0097] Immediately after the start of dyeing, take a 2 - mL sample of the dye solution once, and then take a 2 - mL sample of the dye solution every 10 min during the dyeing process; adjust the pH value of the dye solution sample to neutral with 0.5 mol / L HCl solution and dilute it by a certain multiple;

[0098] The dye solution sample is detected by the CE - UV method. Measure the peak area of the substance peak of Reactive Dye X and substitute it into the corresponding peak area - concentration linear equation to obtain the concentration of Reactive Dye X in the dye solution corresponding to each sampling time. Measure the peak area of the substance peak of the vinylsulfone - type hydrolysis product of Reactive Dye X and substitute it into the corresponding peak area - concentration linear equation to obtain the concentration of the vinylsulfone - type hydrolysis product of Reactive Dye X in the dye solution corresponding to each sampling time. Measure the peak area of the substance peak of the complete hydrolysis product of Reactive Dye X and substitute it into the corresponding peak area - concentration linear equation to obtain the concentration of the complete hydrolysis product of Reactive Dye X in the dye solution corresponding to each sampling time;

[0099] When using the CE-UV method for detection, the background electrolyte used for separating the target substances uses Na2B4O7·10H2O with a concentration of 20.0 mmol / L as the buffering substance, acetonitrile with a volume concentration of 15% and α-CD with a concentration of 20.0 mmol / L as additives together, and the pH value is adjusted to 9 with H3BO3 solution;

[0100] In step (4), the concentrations of 9 substances in the dye solution corresponding to each sampling time are obtained. These 9 substances are Reactive Red 195, Reactive Black 5, Reactive Blue 19, the vinyl sulfone type hydrolysis product of Reactive Red 195, the vinyl sulfone type hydrolysis product of Reactive Black 5, the vinyl sulfone type hydrolysis product of Reactive Blue 19, the complete hydrolysis product of Reactive Red 195, the complete hydrolysis product of Reactive Black 5, and the complete hydrolysis product of Reactive Blue 19;

[0101] (5) Calculate the exhaustion rate of reactive dye X at each sampling time during the actual dyeing process. The calculation formula is as follows:

[0102]

[0103] In the formula, C0 is the concentration of reactive dye X in the dye solution at the start of dyeing; C t总 is the sum of the concentration of reactive dye X, the concentration of the vinyl sulfone type hydrolysis product of reactive dye X, and the concentration of the complete hydrolysis product of reactive dye X in the dye solution corresponding to the t-th moment (each sampling time) during the dyeing process;

[0104] In step (5), the exhaustion rates of the 3 reactive dyes in the dye solution corresponding to each sampling time are obtained. The results are shown in the following table:

[0105]

[0106] In the table, SES-SES-black-5 represents Reactive Black 5, VS-VS-black-5 represents the vinyl sulfone type hydrolysis product of Reactive Black 5, HES-HES-black-5 represents the complete hydrolysis product of Reactive Black 5, SES-blue-19 represents Reactive Blue 19, VS-blue-19 represents the vinyl sulfone type hydrolysis product of Reactive Blue 19, HES-blue-19 represents the complete hydrolysis product of Reactive Blue 19, SES-Cl-red-195 represents Reactive Red 195, VS-Cl-red-195 represents the vinyl sulfone type hydrolysis product of Reactive Red 195, HES-HES-red-195 represents the complete hydrolysis product of Reactive Red 195, and C * represents concentration.

[0107] To verify the accuracy of the method of the present invention, in step (4), one more sample of the dye liquor is taken each time; the dye liquor sample is 2 mL; the pH value of the dye liquor sample is adjusted to neutral with 0.5 mol / L HCl solution and diluted by a certain multiple; the absorbance of the dye liquor sample is detected by the UV-Vis method. Assuming that the dye liquor sample is still a true solution and conforms to the additivity of light, the concentration of reactive dye X in the dye liquor sample at each sampling moment during the actual dyeing process is calculated according to the following formula:

[0108] A1 = K SES-Cl-red-195 bC SES-Cl-red-195 + K SES-Cl-black-5 bC SES-Cl-black-5 + K SES-Cl-blue- 19 bC SES-Cl-blue-19 ;

[0109] A2 = K SES-Cl-red-195 bC SES-Cl-red-195 + K SES-Cl-black-5 bC SES-Cl-black-5 + K SES-Cl-blue- 19 bC SES-Cl-blue-19 ;

[0110] A3 = K SES-Cl-red-195 bC SES-Cl-red-195 + K SES-Cl-black-5 bC SES-Cl-black-5 + K SES-Cl-blue- 19 bC SES-Cl-blue-19 ;

[0111] In the formula, A1 is the absorbance measured for the dye liquor sample at a wavelength of 290 nm; A2 is the absorbance measured for the dye liquor sample at a wavelength of 600 nm; A3 is the absorbance measured for the dye liquor sample at a wavelength of 255 nm; K * represents the absorption coefficient (when C * is the mass concentration), and K is obtained by using pure solutions of each reactive dye with known concentrations at different wavelengths to obtain A (absorbance) through a UV-visible spectrophotometer * ; b represents the solution thickness, i.e., the optical path;

[0112] The exhaustion rate of each of the 3 reactive dyes in the dye liquor corresponding to each sampling moment is calculated from the concentration of reactive dye X in the dye liquor sample at each sampling moment during the actual dyeing process. The results are shown in the following table.

[0113]

[0114] In addition, the present invention also detects the exhaustion rate during the single-dyeing process of reactive dyes with reference to the above method. The basic process is the same as above, except that only one reactive dye is selected when preparing the dye liquor, namely reactive black 5, reactive red 195 or reactive blue 19. The test results are asFigures 9 to 14 as shown

Claims

1. A method for detecting the color absorption rate during the process of dyeing with reactive dyes in a combined color, characterized in that, During the process of dyeing with two or more reactive dyes, a dye liquor sample is taken at time t. After adjusting the pH value to neutral and diluting it, the CE-UV method is used for detection. The peak area of the substance peak of the target in the dye liquor sample is measured, and the concentration of the target in the dye liquor corresponding to time t during the dyeing process is obtained through calculation. Furthermore, the exhaustion rate of each reactive dye corresponding to time t during the dyeing process is obtained. Time t is any one or more moments during the dyeing process. The target is a reactive dye or a hydrolysis product of a reactive dye. The elution position of the target is determined by the standard addition method. The formula used for calculation is a linear equation, which is obtained by performing CE-UV detection on the target at different concentrations to obtain the electrophoresis spectrum, and then performing linear fitting on the peak areas of the target in the electrophoresis spectrum and the corresponding concentrations. The formula for calculating the exhaustion rate of any reactive dye X corresponding to time t during the dyeing process is as follows: where C0 is the concentration of the reactive dye X in the dye bath at the start of dyeing; C t总 is the sum of the concentrations of the reactive dye X and its hydrolysis products in the dye bath corresponding to time t during the dyeing process.

2. A method for detecting the color uptake rate during the mixing dyeing process of reactive dyes, according to claim 1, characterized in that Two or more reactive dyes are reactive red 195, reactive yellow 145, and reactive blue 194.

3. A method for detecting the color uptake rate during the process of mixing and dyeing with reactive dyes according to claim 2, characterized in that, When using the CE-UV method for detection, the background electrolyte used for separating the target uses Na2B4O7·10H2O as the buffering substance, acetonitrile as the additive, and the pH value is adjusted with H3BO3 solution.

4. A method for detecting the color absorption rate during the process of mixing reactive dyes for dyeing, according to claim 3, characterized in that In the background electrolyte used for separating the target, the concentration of Na2B4O7·10H2O is 10.0 mmol / L, the volume concentration of acetonitrile is 15%, and the pH value is 8.

5.

5. A method for detecting the color absorption rate during the process of mixing and dyeing with reactive dyes according to claim 1, characterized in that, Two or more reactive dyes are reactive black 5, reactive red 195, and reactive blue 19.

6. A method for detecting the color uptake rate during the process of dyeing with a mixture of reactive dyes, as claimed in claim 5, wherein, When using the CE-UV method for detection, the background electrolyte used for separating the target uses Na2B4O7·10H2O as the buffering substance, acetonitrile and α-CD as the additives together, and the pH is adjusted with H3BO3 solution.

7. A method for detecting the color uptake rate during the process of mixing reactive dyes for dyeing, characterized in that, In the background electrolyte used for separating the target, the concentration of Na2B4O7·10H2O is 20.0 mmol / L, the volume concentration of acetonitrile is 15%, the concentration of α-CD is 20.0 mmol / L, and the pH value is 9.

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