Preparation Of Photonic Crystal Capillary Column And Its Application In Pressurized Capillary Electrochromatography

Photonic crystal capillary columns have the advantages of homogeneously packed,huge specific surface area and nanoscale channels,which have good application potential when coupled with pressurized capillary electrochromatography(pCEC).The thesis is divided into six chapters.The first chapter described the basic theory and application of CEC and pCEC,and provided an overview on capillary column and antibiotic residues in food of animal origin.The electrical double layer,the electroosmotic flow,the joule heat,the preparation of packed capillary clumn and photonic crystal capillary column were elaborated in detail.The second chapter summarized the preparation method of photonic crystal capillary columns.After the optimization of the packing conditions,the effective and reliable preparation method was determined as follows:the filling method was gravity self-assembly facilitated by pressure;the suspension solvent was toluene;the slurry concentration was 400 mg/mL;the calcination temperature was 600?;the inner diameter of capillary was100?m;the effective length was 10 cm.Compared with an empty capillary and a regular capillary packed with 1.7?m particles,the photonic crystal capillary column had a Bragg diffraction because of the face-centered cubic structure.The result of SEM showed that the photonic crystal capillary column was uniformly prepared.In the third chapter,the intra day and inter day repeatability and batch to batch repeatability of photonic crystal capillary columns were investigated.The RSD of retention time were 0.6%,1.3%and 1.5%and the RSD of peak area were 1.6%,2.2%,and 3.8%respectively,which showed that the preparation method was reliable.On this basis,the capillary columns with particle size of 315 nm to 3000 nm were fabricated to investigate the double layer overlap and the electroosmotic flow,which indicated that the smaller of the stationary phase particles,the faster the linear velocity and the greater of contribution rate of electroosmotic flow.In the fourth chapter,the effects of pressure and pump flow on retention time and peak area were investigated,which showed that the peak area could be adjusted by pump flow and the retention time could be adjusted by pressure.The photonic crystal capillary columns with particle size of 315nm?420 nm?515 nm?670 nm and 780 nm were prepared to study the electrochromatographic characteristics by neutral molecules.The plate height-linear velocity curves were made.It showed that when the linear velocity was in the range of 0~0.40 mm/s,plate height decreased with the increase of the linear velocity,which conform to the van Deemter curve.When the linear velocity was over 0.40 mm/s,it was in contrary.And at the optimum linear velocity for the best plate height were 0.33 mm/s,0.40 mm/s,0.44 mm/s,0.48 mm/s and 0.50 mm/s,respectively,for the individual particle sizes,which were obviously much lower than predicted by theory.This phenomenon may be due to the effect of joule heat.In chapter five,the photonic crystal capillary column was applied in the determination of five sulfonamides in milk.The five sulfonamides were baseline separated in 5 minutes.The speed was increased by 81%compared to cLC.The optimized conditions were shown as follows:mobile phase was acetonitrile/phosphate buffer(5 mmol/L,pH=7.68)(30/70,v/v)with 0.10%triethylamine;applied voltage is-8 kV and the UV detection wavelength was 268 nm.The results indicated that the linear rang was 0.1 mg/L-1.0mg/L(R~2?0.9990),the limits of detection was 0.02-0.04 mg/L.In chapter sixth,we summarized the whole theses and looked into the future perspective.