CAPILLARY ELECTROPHORESIS USING AIR AND HELIUM AS COOLING FLUIDS

A comparative study on the properties of helium and air as thermostatt ing fluids in Capillary Electrophoresis (CE) has been carried out. Equ ations that relate the properties of fluids to their control of the te mperature of the capillary are shown. Results from theory and experime nts are compared under different cooling conditions, i.e., natural and forced gas convection, using air and helium. Experimental results are qualitatively in good agreement with those predicted by theory. The b etter thermostatting capability of helium compared to air is demonstra ted by an improved efficiency in real separations and a lower degree o f denaturation of a thermolabile protein during its purification by CE . (C) 1995 John Wiley & Sons, Inc.