Pressurized Capillary Electrochromatography Coupled With Inductively Coupled Plasma Mass Spectrometry In The Analysis Of Mercury And Arsenic Speciation

Mercury and arsenic are human carcinogens,and the toxicity of them varies widely from species to species,drawing a highly desirable demand to their speciation analyses in biological samples.Inductively coupled plasma mass spectrometry?ICP-MS?is one of the most outstanding technique applied to a wide range of applications in metal determination,because of its exceptional detection power,multi-elemental and isotopic capabilities and wide dynamic range?7⁹?.Capillary Electrochromatography?CEC?is a new type of separation and analysis technology by combining electromigration principle of capillary electrophoresis and chromatographic separation principle of high performance liquid chromatography,offering both high separation efficiency and high separation selectivity.The hyphenation of CEC and ICP-MS combines the advantages of both technologies,showing potential in the measurements of total metal and individual elemental species in the micro-volume samples.In the first chapter,the necessity for specation analysis of mercury and arsenic,separation and detection methods for mercury and arsenic species,the coupling of pressurized capillary electrochromatography and inductively coupled plasma mass spectrometry are reviewed.In the second chapter,an analytical method for mercury speciation analysis was developed by using labmade reversed phase capillary column as the separation column and the nanoflow nebulizer as the sheathing interface.A 100?m i.d.×360?m o.d.×15 cm long capillary column was packed with 5?m C₁₈ sphere particles in our lab.The electrochromatographic electrolyte consisted of 2 mM borate buffer?pH 8.97?,2 mM L-cysteine and 10%v/v methanol,and was fed by a high-pressure pump at.0.15 mL/min.A separation voltage of-5kV was applied along the separation column.Three mercury species were baseline separated within 8 min under the optimized conditions.In the third chapter,microchip-based monolithic capillary electrochromatography was hyphenated with inductively coupled plasma mass spectrometry?ICP-MS?for metal speciation analysis.The feasibility of the proposed coupling was demonstrated by speciation analyses of arsenic in certified fish tissue?GBW 09115?and mercury in certified human urine?GBW 10029?,proving its suitability in practical analysis.In the fourth chapter,a summary to all studies in this thesis was made,and the future applications of capillary electrochromatography with inductively coupled plasma mass spectrometry are prospected.