Capillary Electrophoresis Analysis of Cations in Water Samples. An Experiment for the Introductory Laboratory

Abstract

Capillary electrophoresis is gradually working its way into the undergraduate laboratory curriculum. Typically, experiments utilizing this newer technology have been introduced into analytical or instrumental courses. We have introduced an experiment into the introductory laboratory that utilizes capillary electrophoresis to identify and quantitate cations in common water samples. This experiment can be done in a lab, as a "dry-lab", or as an in-class exercise. Students explore a number of basic separation topics and work with figures of merit for real and meaningful samples. We have adopted a strategy where students encounter various instruments and methods of analyses multiple times throughout the curriculum. The level of sophistication in the exposures increases with the experience level of the students. Through this repeated exposure students will gain a better and fuller understanding of these methods than they would with a single exposure to the technique in the analytical or instrumental laboratory. This is the first of at least four experiments that our chemistry and biochemistry students encounter involving capillary electrophoresis methods.

Detection and Separation of Inorganic Cations in Natural, Potable, and Wastewater Samples Using Capillary Zone Electrophoresis with Indirect UV Detection

“…When ions have dissimilar, slower mobilities than the carrier electrolyte, a non-symmetrical peak shape can appear [ 20 ]. Peak shape ameliorates as the mobility of the analyte more closely matches that of the compound used for indirect detection [ 21 ]. The effects of electrolyte additives, running buffer, pH and other CE conditions on the analysis and separation of cations in drinking water and other solutions have been investigated and optimized in several recent studies [ 22 ] [ 23 ] [ 24 ] [ 25 ].…”

Capillary Electrophoresis with Laser-Induced Fluorescence Detection for the Diagnosis of Phenylketonuria: A Versatile Wet or Dry Laboratory Experiment in Upper-Level Undergraduate Analytical Chemistry

“…A number of undergraduate laboratory experiments utilizing CE have been developed subsequent to the availability of CE instrumentation analyzing various small molecules, − inorganic ions, − and biopolymers. ,− While effective in demonstrating the use of CE across a wide range of compounds, these experiments utilize UV absorbance almost exclusively as a means of detection while neglecting to utilize other detection methods. To our knowledge, an undergraduate laboratory experiment using CE-LIF has yet to be published.…”

Detection and Quantification of Inorganic and Organic Anions in Natural, Potable, and Wastewaters in Northern New York Using Capillary Zone Electrophoresis and Indirect UV Detection

“…Capillary electrophoresis has been employed in recent years to examine ions in water and other media [ 7 – 13 , 16 – 20 ]. Particular interest is in capillary zone electrophoresis (CZE), an attractive separation method based on mass to charge ratios and the differences in mobilities among the various ions.…”