Prepartion Of Monolithic Silica Capillary Column And Its Application In Food Analysis

Sol-gel technology was applied to prapare the non-hybrid and hybrid monolithic silica capillary column, tetramethylsilane(TMOS) and the mixture of TMOS and methyltrimethoxylsilane (MTMS) was used as the initial reactants. The non-hybrid monolithic silica capillary column was modificated and chromatographic performance was tested. The non-hybrid monolithic silica capillary column which was modificated with octadecyltriethoxysilane was used to separate alkylbenzenes, aromatic amine, the semicarbazide and 1-amino-hydantoin and organic acids by capillary electrochromatography. A method was developed for simultaneous determination of eight food additives by high performance capillary electrophoresis(HPCE).It was introducted that classification, research situation at home and abroad, application of the CEC monolithic column and the working principle of the capillary electrochromatography. Sol-gel technology was applied to prapare the non-hybrid and hybrid silica capillary column in a 100μm fused-silica capillary, TMOS and the mixture of TMOS and MTMS was used as the initial reactants. The influence of the reactants on the monolithic silica capillary column was discussed. The conditions of praparing column were optimized, the aging temperature was 40℃, the concentration of acetic acid is 0.01mol/L. The optimum content of PEG for preparing the non-hybrid monolithic column is 0.44g and the optimum content of PEG for preparing the hybrid monolithic column is 0.38g, the best ratio of TMOS/ MTMS is 9:1.The non-hybrid monolithic silica capillary column was modificated with octadecyltriethoxysilane and the chromatographic performance of the modified monolithic silica capillary column was tested by alkylbenzenes. The retention mechanism of the modification column was discussed. The weaker hydrophobic capability of alkylbenzenes, the faster it flow in the column. For the same column, the relative standard deviation (RSD) of the retention time is between 1.14% and 1.74%. The column efficiency for the benzene is up to 8642 N/m.The non-hybrid monolithic silica capillary column which was modificated with octadecyltriethoxysilane was used to separate alkylbenzenes, aromatic amine, semicarbazide and 1-amino-hydantoin and organic acids. A method was developed for seperated oxalic acid, succinic acid, artaric acid and citric acid, the linear range was 15μg/mL～1000μg/mL, the linear correlation coefficient was between 0.9989 and 0.9995, the average recovery was between 91.3% and 103.1%, and the RSD was less than 6.52%(n=5) and the detection limit was 3.0μg/mL～7.5μg/mL.A method was developed for simultaneous determination of eight food additives by HPCE, such as C.I. Food Blue 2, vanillin, sorbic acid, benzoic acid, C.I.Food Yellow 3, C.I. Food Red 10, amaranth, and tartrazine. The mixture of phosphoric acid and borax buffer was used as running buffer. Samples such as drinks, jelly and confiture were detected at 240 nm. Baseline separation was achieved. Analysis time for each sample was whitin 8 min. Under these conditions, the linear range was 2.5μg/mL～1000μg/mL, the linear correlation coefficient was between 0.9986 and 0.9998, the average recovery was between 85.2% and 100.3%, and the RSD was less than 6.98%(n=5), and the detection limit was 0.25μg/mL～10μg/mL.