Christine L. Copper
Ph.D., University of Tennessee
U.S. Naval Academy 572M Holloway Road
Annapolis, MD 21402-5026
Professor Copper focuses on development of separation and detection methods for environmentally important molecules. Specifically, capillary electrophoretic and microchip separation methods are being developed to study environmental pollutants, explosives, and chemical warfare agent simulants. These projects are performed in conjunction with researchers at the Naval Research Laboratory, Washington, D.C.
General Overview of Capillary Electrophoresis and Microchip Separations
Chemical separations are essential to many areas of science. Some example uses of chemical separations include detection of illegal drug use by individuals, purification of medications, analysis of foods for the presence of harmful pesticides, or determination of the amount of caffeine in coffee.
Chemical species are separated in capillary electrophoresis (CE) by placing the sample to be analyzed into a small (inner diameter of 50 mm) glass tube which contains a buffer solution and applying a high (20-30 kV) voltage across the length (typically 35 cm) of the tube. The field that is applied causes different chemical species, according to their charge and size, to travel at different rates through the tube towards a detection system.
Microchip separation devices are a very recent development in analytical chemistry. Simply described, these devices are made by etching small (~25 mm) channels in a glass slide and fusing another glass slide on top of the channel-containing slide. These channels can be filled with various buffer solutions and can be used for electrophoretic separations (similar to those performed using CE).
Various detection systems can be used in CE or microchip experiments. The most common systems are those that shine light from an ultraviolet lamp or a laser through the glass column or channels. Depending on the chemical species, this light could either be absorbed or could cause the species to emit light of a different wavelength. Either of these events can be easily seen using additional detection equipment such as a photomultiplier tube.
Applications of Capillary Electrophoresis and Microchip Devices
Currently, Dr. Copper is working with Dr. Greg Collins at the Naval Research Laboratory (NRL) in Washington, D.C. on CE and microchip separation projects involving chemical warfare agent simulants, explosives, and environmental pollutants.