Analysis Of Trace Sarcosine By Capillary Electrokinetic Chromatography With Laser-induced Fluorescence Detection

Capillary electrokinetic chromatography including capillary electrophoresis and capillary electrochromatography, possesses high separation efficiency. Laser induced fluorescence detection technology (LIF) provides excellent detection sensitivity. The combination of capillary electrokinetic chromatography with laser induced fluorescence detection can offer high efficiency and sensitivity along with the benefits of small sample requirement and has attracted many attentions in the field of trace analysis. To carry out the efficient analysis and sensitive detection of amino acids which are indicators of disease is of great significance for strengthening disease prediction and related environmental security analysis.To form the efficient analysis and sensitive detection of sarcosine, which is a typical indicator in the diagnosis of prostate cancer, is significant and valuable for disease prediction. In this thesis, quick and efficient electrokinetic chromatographic separation of trace sarcosine by capillary-electrokinetic chromatography with LIF detection was focused and studied. And three chapters are involved and listed as follows:In chapter 1, introduction. A review on the analysis of amino acids was presented. The basic properties of sarcosine and amino acids were pictured. The process of analytical methods for amino acids and sarcosine were summarized. The electric micro-separation methods coupled with LIF were also introduced. And then the topic basis and scheme of this thesis were proposed.In chapter 2, the method for sensitive analysis of trace sarcosine, phenylalanine, tyrosine by using capillary electrophoresis (CE) coupled with LIF was established. experimental parameters for LIF derivation of these amino acids including pH value, concentration of buffer solution, concentration of reaction reagents, reaction temperature and reaction time, were investigated. And the separation conditions for CE such as pH values and salt concentrations of mobile phase, content of organic modifier, applied voltage were optimized in detail. Under the optimum conditions, efficient separation and sensitive detection of trace sarcosine were achieved within 10 min. The calibration linearity range from 3.0×10-7 mol/L to 7.0×10-6 mol/L was gained and the LOD (3S/N) of sarcosine was 1.0×10-7 mol/L. Several kinds of technology for sample extraction, purification treatment were further explored. The parameters for a better purification treatment were evaluated and optimized. The analysis of urine samples was carried out, and satisfactory recoveries ranging in 91.5%～106% were successfully acheived.In chapter 3, a new method of capillary electrochromatography (CEC)-LIF detection for the analysis of trace sarcosine was developed. The electrochromatography separation behavior of sarcosine was investigated. The parameters such as component of organic phase, separation voltage and pump pressure and other factors on sarcosine in TFA-ACN system were studied. Based on the coumn of Cs column, electrochromatography method for the separation of sarcosine with other ten amino acids were examined in detail. The efficient separation of 11 amino acids was achieved within 30 min. And high sensitive detection of 10 amino acids was accomplished. The LOD (3S/N) of sarcosine is 5.0×10-8 mol/L, the linearity range of analytical concentration was in 2.0×10-7 mol/L ～2.5×10-5 mol/L. Applied to sarcosine in urine, acceptable recoveries run in the range of 100.3%～116.5% This technology promotes a potential new technical way for sarcosine efficient analysis.