| Inorganic ions are important evaluation parameters in the fields of food,chemistry,pharmacy,and environmental testing,which providing reliable guarantee for quality control and supervision.The concentration of ions reflects not only the quality of product,but also the process of production.Therefore,the effective detection of ions has good practical significance.With the development of science and improved analytical techniques,there are many methods to detect inorganic ions,such as High Performance Liquid Chromatography(HPLC),Ion Chromatography(IC),Capillary Electrophoresis(CE).Capillary electrophoresis(CE),also known as high performance capillary electrophoresis(HPCE),which has the advantages of high separation efficiency,fast separation speed,simple equipment and low sample volume is a popular detection technology and has been widely used in many fields.Contactless conductivity detection is a relatively new conductance measurement technology,which realizes the detection by measuring the solution impedance between two detection electrodes.It is suitable for the detection of ionic because of the advantages of simple structure,easy miniaturization,and without contact between the electrode and solution.In this paper,three researches have been carried out by using the self-made simple capillary electrophoresis-capacitively coupled contactless conductivity detection device.Inorganic anion contained in mineral water,explosive residue,and Chinese medicinal materials were detected.There are four chapters in this paper.Chapter 1:This chapter mainly introduced the historical background,principle,separation mode,and characteristics of capillary electrophoresis,also summarized the development course,principle,characteristics and application of CE-C~4D.Chapter 2:Based on the self-built CE-C~4D device,a rapid method was developed for determination of anions and cations in drinking water by injecting samples at both ends of capillary in the same time.In this work,six ions were separated in 3 min by optimizing the length of the capillary,the position of the detector,the concentration and pH of buffer.The linearity was good in the range of10-1000?M.The limit of detections(LODs)and limit of quantifications(LOQs)were0.17-1.38?M and 0.57-4.05?M,the relative standard deviation is in a range between0.9-4.7%for migration time and peak area.The method has been applied to the detection of ions in four brands of drinking water,and the results was satisfactory.Chapter 3:Determination of explosive residues ions provides important information for the identification of explosive species.In this work,a method was developed for determination of ions in explosive residues by self-built CE-C~4D device.The method provided technical support for the identification of explosives.Six ions were rapid separated in 4 min with 20 mM MES/His as the separation buffer.The capillary was coated with 0.0.3 mM CTAB.The limit of detections(LODs)and limit of quantifications(LOQs)were 0.11-0.15?M and 0.36-0.49?M about method with good precision.The method successfully applied for the detection of anions in inorganic explosive residues.Chapter 4:The content of heavy metals is an important indicator for evaluating the quality in Chinese herbal medicines.In this work,a method was developed for determination of heavy metal ion in Chinese herbal medicines with self-built CE-C~4D device.Pb2+?Cd2+?Cu2+?Co2+were separated in 3 min with 20 mM MES/His as the separation buffer.The limit of detections(LODs)and limit of quantifications(LOQs)were 0.25-0.45?M and 0.81-1.46?M about method.The method has been successfully applied to the determination of four heavy metal ions in Angelica sinensis and Lycium barbarum.The results were satisfactory and the contents of heavy metal ions met the relevant national regulations. |
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