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Analytical methods. Houdková Chocholáčová. Analytical methods. Absolute analytical methods (direct evaluation of the analytical signals with regard to the analyte concentration) Relative analytical methods (which use calibration function, sample standards are obligatory). Gravimetry
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Analyticalmethods Houdková Chocholáčová
Analytical methods • Absolute analyticalmethods (direct evaluation of the analytical signals with regard to the analyte concentration) • Relative analytical methods(which use calibration function, sample standards are obligatory) • Gravimetry • Volumetry (titration methods) • Instrumental methods – CZE – GC
Electromigration methods • use motion of ionized particle in the electrical field • velocity motion is directly proportional to their charge and size
CZEseparation and determination of cations, anions and components without charge INSTRUMENTATION • Capillary • Source: 20 – 30 kV • Platinum electrodes • Vials with buffer solutions • Detectors • Time (such 10 minutes) • Electroforetogram
Capillary • size: 60 cm x 75 µm • silica capillary covered by polyamide • the whole capillary contains 10 µl, sampling volume is 10 nl • various variant of sampling (hydrodynamic, electrokinetic)
Principle of CZE • method for separation and determination of cations, anions and so components without charge on the basis of diferent electrophoretic movement • sample at start → insert electrical field → components A,B are moving with diferent constant speed towards to electrode → origin zone • to origin electroosmotic flow (EOF) and his impact on separation and shape peaks
Application • determination of dye at foodstuff • monitoring composition of foodstuff during the production and storage • pollution • analyse of DNA (genetic engineering) • and so, and so, and so …
Reference • website • Analytická chemie, Lumír Sommer (textbook) • laboratory from ISA