Analysis Of Sarcosine By Capillary Electrokinetic Microseparation Method Coupled With Electrochemiluminescence Detection

Capillary electrokinetic microseparation method possesses of advantages in small amount of reagents and sample consumption, high separation efficiency and rapid separation. Electrochemiluminescence (ECL) caused by the redox reaction on the surface of electrode could produce sensitive chemiluminescence,. The combination of both technologies has got the attention in the forefront of efficient analysis of trace substances. sarcosine has been proved as a indicator of prostate cancer, and the method for efficient analysis of trace sarcosine is desired. In this thesis, sensitive profiling of sarcosine has been established by using electrophoresis and electrical chromatography, which might extend a new approach for efficient analysis of sarcosine in complex samples.Three chapters are involved in this thesis and shown as follows:In chapter 1, review. The properties, the effect and the detection methods for sarcosine have been summarized. The developments of the detection methods for sarcosine are also presented, and thus the aim and experimental scheme of this thesis were put forward briefly.In chapter 2, a technology for the detection sarcosine by capillary electrophoresis coupled with electrochemiluminescence was established. Various factors including distance between separation column and electrode, buffer solution have been well investigated with triethylamine, and the mechanism were studied. And then the analytical method for the separation of sarcosine, proline and hydroproline was also established. The conditions such as mobile phase, applied voltage and injection time were investigated in detail. Under the optimal conditions, satisfactory separation of sarcosine, proline and hydroproline was achieved.the linear range of sarcosine was between 1.0×10-6 and 1.0×10-5 mol/L, and the detection limit of Sarcosine was 5.0× 10-7 mol/L. The RSD of peak height was between 1.5% and 4.9%, and the RSD of migration time was between 0.6% and 2.4%. Applied to urine, the average recoveries of sarcosine were between 96.11%and 99.75% at three concentrations (1.0×10-6, 5.0×10-5 and 1.0×10-5 mol/L) of fortified samples. The RSD of high peak was less than 5.0%, the RSD was less than 4.0%, and the RSD of the retention time recovery was less than 6.0%.In chapter 3, a method for the detection of sarcosine by capillary electrochromatography with electrochemiluminescence was established. Chromatographic behaviors of sarcosine was studied with different capillary chromatographic columns. The detection factors including the component of mobile phase, distance between chromatographic column and electrode and pH value and so on, were investigated for the sensitive analysis of sarcosine. Based on capillary electrochromatography (CEC) technology, the characteristics of sarcosine were determined. The conditions affecting the separation and detection of sarcosine were investigated with the presence of a variety of ammo acids, effexts of the component of mobile phase, applied voltage and injection time was also studied. Under the optimal conditions, by using a 25 mmol/L phosphate solution (pH 8.5) containing 50%(v/v) acetonitrile as running buffer, satisfactory separation of sarcosine, proline and hydroproline was achieved with 15 kV applied voltage. The linear range of sarcosine was between 1.0×10-5mol/L and 5.0×10-4 mol/L. The limit of detection was 3.0×10-6 mol/L, which might extend a potential approach for sensitive analysis of sarcosine with further improvements.