UNIVERSAL CALIBRATION IN SIZE-EXCLUSION CHROMATOGRAPHY AND THERMAL FIELD-FLOW FRACTIONATION

Universal calibration in size exclusion chromatography (SEC) is a calibration technique that makes possible the transfer of calibration data obtained using polymer standards to other polymers of interest. This polymer-transferable calibration requires ancillary information on intrinsic viscosity. Calibration must be repeated for every new column. There is a perception that universal calibration does not apply to thermal field-flow fractionation (thermal FFF). Here it is shown that a different but perhaps more ''universal'' form of calibration applies to thermal FFF. Calibration constants for thermal FFF are physicochemical constants (describing ordinary and thermal diffusivities), not system constants. Thus calibration constants obtained from one thermal FFF system can, in principle, be transferred to every thermal FFF system in the ''universe''. The implications of this universal (system-transferable) calibration in thermal FFF are discussed in relationship to traditional SEC universal calibration.