Detemination Of Polysaccharide Composition Of Camellia Nitidissima Chi,Liupao Tea And Food Additives By Capillary Electrophresis

In this paper, the methods of analyzing the composition of polysaccharides and the additives in food, and the method of separating and enriching the samples from off-line and on-line are summarized. The monosaccharide composition and molar proportions of polysaccharide in Camellia nitidissima Chi and Liubao tea which are unique products in Guangxi was analyzed by micellar electrokinetic capillary chromatography. Additives in food was pretreated by solid phase extraction, dispersion liquid liquid micro extraction and field amplified sample stacking. The specific work is as follows:(1) Ultrasonic-assisted extract the polysaccharide from Liupu tea. Ethanol was added to the solution of Liupu tea and Camellia nitidissima Chi, and crude polysaccharide was precipitated. Then the polysaccharide was purified by activated carbon and the volume ratio of 4:1 chloroform and n-butanol, and degraded by strong acid in high temperature. The polysaccharide hydrolysate was determined by micellar electrokinetic capillary chromatography, and internal standard method was used for its quantitative analysis after derivatived by 1-pheny-3-methyl-5-pyrazolone (PMP). After optimized separation conditions, the results showed that the composition of monosaccharide of polysaccharide in Camellia nitidissima Chi and Liubao tea were arabinose, glucose, rhamnose, mannose, galactose and galacturonic acid. Their ratios were 0.13:0.19:0.09:0.05:0.16:0.03 for Camellia nitidissima Chi, and 0.29:0.02: 0.10:0.06:0.42:0.35 for Liubao tea. The linear relationship of monosaccharide was good, and the linear correlation coefficient is above 0.992.(2) The extraction ability of different solid phase extraction column, the type of the liquid, the flow rate of the liquid and the choice of the internal standard were investigated. Food additives were extracted by HLB solid phase extraction column, and determinated by capillary zone electrophoresis. The internal standard method of quantitative analysis was applied. After optimized experimental conditions, the results showed that the linear correlation coefficient of each additive was more than 0.99, and the relative standard deviation was less than 5%. The recovery rate of addition was between 102% and 95%.(3) Food preservatives were extracted by dispersion liquid liquid micro extraction. Chloroform was selected as extraction agent and acetone was selected as dispersant. Determination of preservatives by capillary electrophoresis under optimum conditions and internal standard method. The result showed that the linear relationship of each preservative was good and the linear correlation coefficient of each preservative was more than 0.99. The relative standard deviation was less than 6%, and the recovery rate of sample addition was between 99% and 103%.(4) Several preservatives and pigments in food were enriched by field amplification and determined by capillary electrophoresis. The water column introduction time, separation voltage and the pH of buffer solution were optimized. Under the best experimental conditions, five kinds of additive showed good linear relationships, and correlation coefficient was above 0.99. The relative standard deviation was not more than 8%, and the recovery rate was between 97% and 103%.