| Capillary electrophoresis is a kind of liquid phase separation and analysis technique,which is based on the capillary as the separation channel and the direct current electric field as the driving force.Since the advent of 1980 s,its theory,separation patterns,instrument and applied research are highly active research field all along.It has been widely used in forensic science,medical science,environmental science,biotechnology and many other fields due to the strong separation ability,fast separation speed,good durability and low cost.Chemiluminescence analysis is a trace analysis method which determines the content of substance according to the light emission of the chemical reaction,which has the advantages of high sensitivity,low cost,no need of light source,can avoid the influence of background light and stray light.Due to the outstanding properties of capillary electrophoresis and chemiluminescence,the combination of these two techniques will bring a great superiority.Ag(?)complex([Ag(HIO6)2]5-)is a new type of oxidant which can oxidize luminol to produce chemiluminescence in alkaline medium.Some substances can enhance or inhibit the chemiluminescence intensity of Ag(?)complex with luminol.In a certain concentration range,the degree of enhancement or inhibition is positively correlated with the concentration of the substance,according to which the standard curve can be established and the actual concentration of the substance can be calculated.Based on this principle,a new capillary electrophoresis-Ag(?)-luminol chemiluminescence method was established to simultaneously detect four kinds of environmental estrogens(Estradiol,4-Nitrophenol,Diethylstilbestrol and Bisphenol A)in milk and simultaneous detect vancomycin and norvancomycin in human serum.The new method has the advantages of low cost,simple operation,environmentally friendly and reliable results.PART 1 Simultaneous determination of four kinds of environmental estrogens in Milk by capillary electrophoresis chemiluminescenceObjective: To establish a new method for simultaneous determination of Estradiol,4-Nonylphenol,Diethylstilbestrol and Bisphenol A in milk by capillary electrophoresis chemiluminescence and apply it to the detection of the estrogens in milk.Method: Estradiol,4-Nonylphenol,Diethylstilbestrol and Bisphenol A were separated by capillary electrophoresis and they all have a significant inhibitory effect on the CL signal of Ag(?)complex-luminol system.In a certain concentration range,the degree of inhibition has a linear relationship with the concentration of the sample and according to this,the standard curve was established and the concentration of the samples were calculated.The experimental conditions were optimized which the concentration of Ag(?)complex(p H was 12.52)was 1.0×10-4 mol/L including 0.04 mol/L NaOH and Na2CO3,the concentration of luminol(pH was 9.21)was 3.0 mmol/L including 6 mmo/L Na2CO3 and NaHCO3,The separation voltage was 14 kV and the injection time was 6 s.The protein was removed from the milk samples using acetonitrile and the supernatant were injected after nitrogen drying,re-dissolving and filtration.Results: Under the optimized conditions,the linear regression equation of Estradiol,4-Nonylphenol,Diethylstilbestrol and Bisphenol A were ?I= 4.798c+20.477,?I=5.2948c+19.616,?I=5.8843c+30.847,?I= 10.2c+29.885,with liner correlation coefficients of 0.9982,0.9980,0.9964 and 0.9965 respectively.The relative standard deviation were 2.49%,1.45%,2.33%,2.37% and the average recovery were 88.68%,90.48%,101.57% and 97.18% respectively.The linear range of Estradiol,4-Nonylphenol and Diethylstilbestrol were both 0.5~30 ?g/ml and the Bisphenol A was 0.5~20 ?g/ml.The detection limits of Estradiol,4-Nonylphenol and Diethylstilbestrol were both 0.25 ?g/ml and the Bisphenol A was 0.1 ?g/ml.Conclusion: A new method for simultaneous determination of Estradiol,4-Nonylphenol,Diethylstilbestrol and Bisphenol A in milk by capillary electrophoresis coupled with luminol-Ag(?)complex chemiluminescence was established which has the advantages of easy operation,low cost of equipment,environmentally friendly and the effect was satisfactory.PART 2 Simultaneous determination of Vancomycin and Norvancomycin in human serum by capillary electrophoresis chemiluminescenceObjective: To establish a new method for simultaneous determination of Vancomycin and Norvancomycin in human serum by capillary electrophoresis chemiluminescence and apply it to the detection of the Vancomycin and Norvancomycin in human serum.Method: The serum samples were concentrated and purified by C18 solid phase extraction pellets.The samples were amalyzed under the optimum conditions in which the concentration of Ag(?)complex(pH was 12.17)was 1.0×10-4 mol/L including 0.05 mol/L NaOH,the concentration of luminol(pH was 8.94)was 3.5 mmol/L including 17.5 mmol/L Na2B4O7 and 5 mmol/L Na2CO3,the separation voltage was 15 kV and the injection time was 10 s.Vancomycin and Norvancomycin were separated by capillary electrophoresis and both of them have a significant inhibitory effect on the chemiluminescence signal of Ag(?)complex-luminol system.In a certain concentration range,the degree of inhibition has a linear relationship with the concentration of the samples and according to this,the standard curve was established and the concentration of the sampleS were calculated.Results: Under the optimized conditions,the linear range of both Vancomycin and Norvancomycin were 5~80 ?g/ml,the linear regression equation of Vancomycin was ?I=0.7326c+4.0738,R2=0.9986,and the Norvancomycin's was ?I=0.6000c+2.000,R2=0.9974.The detection limits of Vancomycin and Norvancomycin were both 2.5 ?g/ml and the RSD were 3.6% and 3.8%.The average recoveries were 98% and 88.29% respectively.Conclusion: A new method for simultaneous determination of Vancomycin and Norvancomycin in human serum by capillary electrophoresis chemiluminescence was established and it has the advantages of easy operation,low cost of equipment,environmentally friendly and the effect was satisfactory. |
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