Development Of Capillary Electrophoresis Method For The Analysis Of Reactive Dyes And Their Hydrolysis Products And The Applications In The Printing And Dyeing

Currently reactive dyes are widely used in the field of printing and dyeing.In order to obtain products with specific color,high coloring amount and excellent lifting power,it is crucial to study the physical and chemical properties of various reactive dyes and the changes that may occur during the printing and dyeing process.In this paper,capillary electrophoresis technique combined with ultraviolet detector（CE-UV）was used to study different structural reactive dyes and homogeneous multi-reactive group reactive dyes and their hydrolysis products separately,and to develop a rapid and efficient CE-UV method by qualitative and quantitative study of different structural reactive dyes.The hydrolysis rate of reactive blue 49（Cl-blue-49）was measured at different pH and temperature,which showed that the application of capillary electrophoresis technology in the printing and dyeing industry is very promising.CE-UV developed qualitative and quantitative methods for the analysis of three monochloro-para-triazine and vinylsulfone-type heterogeneous double reactive dyes and their vinylsulfone-type reactive forms and fully hydrolyzed products,and further validated the potential of capillary electrophoresis technology for application in the dyeing and printing industry by comparing their measured dyeing rates with those measured by UV-vis spectrophotometer.Chapter 1 provides an overview of the development of CE,basic theoretical knowledge,common detectors and their principles of action,followed by an introduction to reactive dyes,the object of this study,mainly in terms of the development history of reactive dyes,current research status,hydrolysis principles,analytical methods,and finally,the purpose and significance of this study.In the second chapter,a new method for the qualitative and quantitative analysis of different structures of C.I.Reactive Black 5（SES-SES-black-5）,C.I.Reactive Blue 49（Cl-blue-49）,C.I.Reactive Yellow 145（SES-Cl-yellow-145）and their complete hydrolysis products（HES-HES-black-5,HES-blue-49,HES-HES-yellow-145）by CE-UV was investigated.The CE background electrolyte（BGE）was finally determined to be 10 mmol/L Na₂B₄O₇+15%（V/V）ACN,（pH adjusted to 9.30 with 0.50 mol/L NaOH）by optimizing the sodium borate concentration,polyvinyl alcohol（PVA）,sodium dodecyl sulfate（SDS）,organic additive acetonitrile（ACN）volume percentages and pH conditions.The linearity of the reactive dyes and hydrolysis product concentrations was good in the range of 2.0～100.0 mg/L（correlation coefficient R²>0.9913）at the detection wavelength of 200 nm,and the detection limits（LOD）were in the range of 0.53-1.80 mg/L,which were comparable to the reported CE-UV method.The relative standard deviations of migration time and peak area were in the ranges of 0.19%～0.57%and 2.0%～3.5%,and the spiked recoveries ranged from 97.1%to 104.6%.This showed that CE-UV can accurately quantify the six targets qualitatively.The developed CE-UV method was also used to determine the concentrations of reactive dyes and their hydrolysis products to calculate the hydrolysis rates.By comparing the differences in hydrolysis rates,it was determined that Cl-blue-49 has good reactivity at pH=13.00 and temperature of 80℃,thus demonstrating the potential of CE as an effective separation and analysis technique for application in the dyeing and printing industry.Chapter 3 investigates the CE-UV analysis of C.I.Reactive Red 195（SES-Cl-red-195）,C.I.Reactive Yellow 145（SES-Cl-yellow-145）,C.I.Reactive Blue 194（SES-Cl-blue-194）and vinyl sulfonesulfone-type reactive forms（VS-Cl-red-195,VS-Cl-yellow-145,VS Cl-blue-194）and the fully hydrolyzed products（HES-HES-red-195,HES-HES-yellow-145,HES-HES-blue-194）were qualitatively and quantitatively analyzed by a new method.The CE background electrolyte（BGE）was finally determined to be 10 mmol/L Na₂B₄O₇+15%（V/V）ACN,（pH adjusted to 8.50 with 0.50 mol/L H₃BO₃）by optimizing the sodium borate concentration,volume percentage of organic additive acetonitrile（ACN）and pH conditions.The linearity of the reactive dye and hydrolysis product concentrations at the detection wavelength of 200 nm was good in the range of 1.0～50.0 mg/L（correlation coefficient R²>0.9937）,and the limits of detection（LOD）were in the range of 0.3～1.3 mg/L,which were comparable to the reported CE-UV method,which was comparable to the reported CE-UV method,with the relative standard deviations of migration time and peak area in the ranges of0.39%～1.29%and 1.4%～3.8%.Finally,by comparing the effect of anhydrous sodium sulfate on the separation method,it was shown that the application of CE in the actual printing and dyeing process is feasible and can obtain good stability.Chapter 4 demonstrated that the capillary electrophoresis technique can analyze the dyeing process of reactive dyes by CE-UV testing of actual dyeing of reactive dyes,and can completely separate the products at all levels of the dyeing process,and visually and clearly observe the reactive dye reaction process by taking samples at different intervals.This chapter compares the dyeing rate of single dye and multi-component reactive dyes measured by CE-UV and UV-Vis,and the dyeing rates of both are basically the same.The results show that CE-UV is accurate enough to be used as a new testing tool in determining the dyeing rate of reactive dyes.Chapter 5 mainly introduces the progress of the current research on this topic and the outlook in this direction.The separation of different reactive dyestuffs and their hydrolysis products by CE-UV is summarized.Through the determination of the hydrolysis rate of reactive dyestuffs and the calculation of the dyeing rate in the printing and dyeing process,it is proved that CE has a very promising application in the printing and dyeing industry.The subsequent application of CE needs to be further developed,and it is hoped that it can be applied to the evaluation of dye quality and online monitoring.