Introducing Teflon-HPLC

Abstract

With increasingly ambitious sample return missions and instrumentation of ever-increasing sensitivity and precision, column chromatography appears to be the neglected step-child of isotope geochemistry and little improvement has been brought to it in the past few decades. Traditional column chromatography (i.e., open-system, gravity driven) techniques suffer from significant limitations pertaining to the overall length of column, resin size and diffusion effects, which can severely compromise separation efficiencies. Furthermore, some fine-scale separations still require complicated multi-step, highly time-consuming protocols (e.g. Ni-Mg, [1]). High-performance liquid chromatography (HPLC), while overcoming many of these limitations (e.g. a closed-system setup; the ability to pressurize the system, hence longer columns and better separation; a semi-automated set-up), is not immune to severe drawbacks. Mainly, 1) the liquid flow path often contains glass or metal parts which are easily corroded/dissolved by concentrated acids or organic solvents, leading to contamination of the samples, and 2) the electronic controls and housing are often spatially associated with the HPLC unit, drastically shortening the lifespan of the apparatus as the metallic parts rapidly corrode in these harsh chemical environments [e.g. 2].