Application Of Pressurized Capillary Electrochromatography In Drug And Food Analysis

At present,pressurized capillary electrochromatography(pCEC)is a kind of micro-separation detection technology that has just emerged in the beginning of the 21 st century.It combines the advantages of capillary electrophoresis(CE)and high performance liquid chromatography(HPLC).At the same time,it has the both separation mechanism.The pressure flow and electroosmotic flow are used as the driving force for the sample to be transported in the capillary.Compared with HPLC,pCEC uses a capillary column filled with smaller size particles,which greatly reduces the amount of mobile phase used.Secondly,the pCEC mobile phase under the dual driving force exhibits a plunger type rather than a parabolic type,reducing the peak broadening effect,to a large extent improve the separation capacity of the column.Compared with CE,pCEC introduces the high pressure pump in the liquid phase,which overcomes the problem of bubbles and dry columns in capillary electrophoresis process,reduces the limitations of p H and buffer salts during the separation process.So that the pressurized capillary electrochromatography not only separates the charged material,but also separates the electrically neutral substance,so that it can separate the more complex samples;the gradient elution program for high pressure pumps can also be applied to pCEC.Continuous injection and power supply ensure the stability of the driving force and also improve the efficiency of the column.In this paper,the new methods of separation detection of drugs and food are developed by applying pressurized capillary electrochromatography technology.The main contents and results are as follows:In the first chapter,the basic principle,development process and column technology of pressurized capillary electrochromatography and capillary electrochromatography are introduced.The application and progress of pressurized capillary electrochromatography in drug analysis and food detection are reviewed.In the second chapter,the pCEC method for the simultaneous determination of rhein,emodin,aloe-emodin,chrysophanol and emodin was established by using pressurized capillary electrochromatography.And this method was applied in the composition of anthraquinones in roots of polygonum cuspidatum.The mobile phase was separated by EP-100-20 / 45-3C18 capillary column(total length 45 cm,effective length 20 cm,diameter 100 ?m,ODS filler 3 ?m))-acetonitrile(15:85).It consisted 20 mmol / L Na H2PO4(p H 4.7)and the 0.04 m L / min total flow rate,and the separation voltage was +5 k V,the UV detection wavelength was 254 nm.The results showed that the five anthraquinones were completely separated in 12 min and were linearly correlated in the range of 3.57 ? 162.68 ?g / m L.The correlation coefficient was not less than 0.9982.The established method was applied to the analysis of anthraquinones in Polygonum cuspidatum and achieved good experimental results.The recoveries were between 91.1% and 101.2%,and the relative standard deviations(RSD)ranged from 0.03% to 3.6%.In the third chapter,a new method for the separation and detection of five kinds of polyphenols in sugarcane tissue was established by using pressurized capillary electrochromatography.The mobile phase consisted of 15 mmol / L Na OH buffer solution(p H adjusted to 4.0)and methanol(60:40,V / V).The flow rate is 0.04 m L / min and separation voltage is-5 k V,the UV detection wavelength is set to 280 nm.Using this method,five kinds of phenolic substances of gallic acid,chlorogenic acid,epicatechin,caffeic acid and ferulic acid achieve an effective separation in 35 min(r> 0.9992).The recoveries ranged from 98.1% to 100.4%,and the RSD values were less than 3%.High precision and the less solvent consumption,and provided reference for the determination of phenolic compounds in tissues.In the fourth chapter,a new method for the determination of acrylamide in processed potato chips by pCEC-UV method was established for the first time.The method was characterized by C18 capillary column,15 mmol / L sodium dihydrogen phosphate buffer(p H = 4.7)(15:85,V/V)as the mobile phase,the flow rate is 0.04 m L/min,the separation voltage is-2 k V,the UV detection wavelength is 202 nm,isocratic elution,to achieve a rapid detection of acrylamide.The results showed that acrylamide was the linearity in the range of 2 ? 32 ?g/m L,the correlation coefficient was 0.9994,the recoveries were 95.3% ? 108.1% and the relative standard deviations(RSD)were less than 1.48%.The method has the advantages of simple operation,fast and high efficiency,high sensitivity,high precision,low detection limit and low reagent dosage.In the fifth chapter,the method for separation and detection of three fluoroquinolones residues in pork tissue was established by using pressurized capillary electrochromatography.The samples were extracted with potassium dihydrogen phosphate solution.Mobile phase is methanol and 0.05 mmol / L phosphoric acid(adjusted to p H 2.5 with triethylamine).The UV detection wavelength was 280 nm and the separation voltage was-1 k V.Under optimized conditions,norfloxacin,ofloxacin and ciprofloxacin achieved baseline separation in 25 min.The linear relationship was good(r> 0.9990)in the concentration range of 10 ? 25?g / m L,the recoveries were between 91.1 and 104.6% and the relative standard deviations(RSD)were less than 3.7%,high precision,which meets the requirement of drug residue detection and provides the method for the analysis of fluoroquinolones residues in food safety.