Study On The Novel FI-CE Methods For The Determination Of Effective Components In Cosmetics And Active Compounds In Chinese Herbal Medicines

The hybrid techniques of the analysis instruments are one of the trends of the development of analytical chemistry.The combination of flow injection with capillary electrophoresis(FI-CE)is representative of the trend.The combined technique that integrates the essential favorable merits of FI and CE can significantly expand the application scope of CE by exploring the various on-line sample pretreatments,and overcomes the shortcoming of discontiguous injection of CE.However,since the investigation of FI-CE is based on traditional CE,it has some shortcomings such as lower concentration sensitivity to be improved.Then,it is important to study some on-line concentration methods for FI-CE.Since the application of FI-CE on herbal medicine is already in progress,further investigation must be made to meet the need of quality control of herbal medicine and its preparations.Besides,the separation and determination of analytes in cosmetic by FI-CE is infrequently to be reported.Then,the dissertation consists of four chapters.Chapter 1,the introduction of theoreties and apparatus of CE;the combination of FI and CE was discussed from the necessity of the combined technique,the principle of this technique,split-flow interfaces and the basic FI-CE system setup,as well as novel applications to a variety of analytical problems,and so on.Besides,the application of CE on cosmetic analysis is reviewed in detail.Chapter 2,a simple,rapid and accurate method for the separation and determination of L-ascorbic acid,ascorbyl glucoside and kojic acid in commercial cosmetics was developed by combination of flow injection(FI)-capillary electrophoresis(CE)system for the first time.Under the optimum condition,the separation was achieved within 5 min.The method resulted in excellent linearity,with correlation coefficients≥0.9991 for the three analytes.The detection limits for L-ascorbic acid,ascorbyl glucoside and kojic acid were 3.14,2.67,and 1.15μg/mL, respectively.The repeatability(defined as R.S.D.)was less than 5.0%for the intra-day and inter-day analysis.The levels of the analytes were successfully determined in cosmetic samples with recoveries ranging from 93.7%to 104.1%. Chapter 3,a simple,rapid and accurate method for the separation and determination of rutin,kaempferol,apigenin and quercetin in Herba Leonuri was developed by combination of flow injection(FI)and capillary electrophoresis(CE) for the first time.The separation was achieved within 9 min and the sample(standard solution)throughput rate reached up to 15 h^-1(real sample about 8 h^-1).The method resulted in excellent linearity,with correlation coefficients≥0.9990 for the four analytes.The repeatability(defined as R.S.D.)was less than 5.0%for the intra-day and inter-day analysis.The levels of the analytes were successfully determined in real sample with recoveries ranging from 95.0 to 104.3%.Two extraction methods were investigated to fred the more efficient sample preparation way for Herba Leonuri.Chapter 4,a simple,rapid and sensitive method for the separation and determination of sophoridine and oxymartrine in Fufang Kushen Injection was developed by LVSS-CZE for the first time.Under the optimum conditions, sophoridine was achieved 10.1-and oxymartrine was 9.2-fold improvement in concentration sensitivity relative to conventional CE methods.The repeatability (defined as R.S.D.)was less than 4.0%for the peak area and peak height.