Quasi-adiabatic vacuum-based column housing for very high-pressure liquid chromatography.
A prototype vacuum-based (10(-6)Torr) column housing was built to thermally isolate the chromatographic column from the external air environment. The heat transfer mechanism is solely controlled by surface radiation, which was minimized by wrapping the column with low-emissivity aluminum tape. The adiabaticity of the column housing was quantitatively assessed from the measurement of the operational pressure and fluid temperature at the outlet of a 2.1mm×100mm column (sub-2 μm particles). The pressure drop along the column was raised up to 1kbar. The enthalpy balance of the eluent (water, acetonitrile, and one water/acetonitrile mixture, 70/30, v/v) showed that less than 1% of the viscous heat generated by friction of the fluid against the packed bed was lost to the external air environment. Such a vacuum-based column oven minimizes the amplitude of the radial temperature gradients across the column diameter and maximizes its resolving power.
Waters Corporation, Instrument/Core Research/Fundamental, Milford, MA 01757, USA. Electronic address: Fabrice_Gritti@waters.com.
Fabrice
F
Gritti
Waters Corporation, Instrument/Core Research/Fundamental, Milford, MA 01757, USA.
Martin
M
Gilar
Waters Corporation, Instrument/Core Research/Fundamental, Milford, MA 01757, USA.
Joseph A
JA
Jarrell
D000097:Acetonitriles; D000535:Aluminum; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D017276:Friction; D006358:Hot Temperature; D012997:Solvents; D013696:Temperature; D013816:Thermodynamics; D014618:Vacuum; D014867:Water
D000097:Acetonitriles; D012997:Solvents; D014867:Water; D000535:Aluminum
Adiabaticity; Column efficiency; Column thermal insulation; Fluid enthalpy balance; Vacuum technology; Very high-pressure liquid chromatography