| As the important modern separation and analytical methods,high performance capillary electrophoresis method and high performance liquid chromatography method are two significant branches,which are widely used in the determination of food quality and food safety because of their high efficiency and accuracy.In this thesis,the determination and test of heavy metal ions in food and medicine by HPCE and HPLC methods were studied.It was divided into five chapters:In the first chapter,the application of high performance capillary electrophoresis and high performance liquid chromatography method in the determination of heavy metals in foods and medicines was introduced briefly.And the study background,the basic content and the sketch of experimental scheme were also introduced.In the second chapter,a capillary electrophoresis coupled with indirect UV method was developed to separate four heavy metal ions including Cd2+,Cr3+,Cu2+ and Zn2+ in traditional Chinese medicine Shuanghuanglian oral liquid.The running buffer was 15 mmol/L chromophore imidazole containing 10 mol/L acetic acid at pH 4.5.The experimental conditions of the CE separation method were: 5 s hydrodynamic injection at 0.5 psi,20 kV applied voltage,and UV detection at 218 nm.The results show that the migration time of all the four heavy metal ions was less than 6 min.The calibration curves for four heavy metal ions were linear in the range of 0.5~35 ?g/mL with linear correlation coefficients of 0.9984~0.9999.The limits of detection were in the range of 0.08~0.61 ?g/mL along with the recoveries of 94.2%~103.8%.The analysis results obtained from three real samples demonstrate that the developed method is simple,quick and convenient for routine analysis with low detection limit.In the third chapter,the Ni2+ and Cu2+ metal ions in cigarette were determined by the pre-column deriving HPLC method.The samples were derived by sodium diethyldithiocarbamate before it was analyzed.The experiment used a Hypersil ODS2 C-18 chromatography column as stationary phase and MeOH: H2O(75:25)as mobile phase.The calibration curves for two heavy metal ions were linear in the range of 0.1~30 ?g/mL with linear correlation coefficients of 0.9989~0.9997.The limits of detection were in the range of 0.011~0.017 ?g/mL along with the recoveries of 96.83%~104.50%.The established method including simple operation is accurate,rapid and stable to detect the two heavy metal ions in cigarette with low detection limit.The method can be used as an alternative method of detection of other metal ions.In the fourth chapter,The Pb2+ and Ni 2+ metal ions in soy sauce were determined by the online deriving HPLC method with wet digestion.Sodium diethyldithiocarbamate was used as the deriving agent for heavy metal ions.The experimental conditions are: a Hypersil ODS2 C-18 chromatography column,and MeOH: H2O: Sodium diethyldithiocarbamate(63.5: 35: 1.5)as mobile phase.The calibration curves for two heavy metal ions were linear in the range of 0.5~50 ?g/mL with linear correlation coefficients of 0.9982~0.9990.The limits of detection were in the range of 0.2~0.3 ?g/mL along with the recoveries of 88.1%~91.8%.The method is simple and has good accuracy and precision,which can be used as an alternative method for the determination of heavy metal ions in real soy sauce samples.In the fifth chapter,the content of Pb2+ in the tea was determined by the HPLC method using bis salicylaldehyde-o-phenylenediamine as derivatizing agent.The detection wavelength was 226 nm with Hypersil ODS2 C-18 column as stationary phase and methanol: water(80:20,v / v)as mobile phase.The linear range of Pb2+ was 0.1~30 ?g/mL and the linear correlation coefficient was 0.9988.The limit of detection was 0.01 ?g/mL along with the recoveries of 91.87%~96.96%.The method has high sensitivity and stability with satisfactory results,which can be used for the detection of Pb2+ in tea samples. |
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