TY - JOUR TI - Evaluating the advantages of higher heat conductivity in a recently developed type of core-shell diamond stationary phase particle in UHPLC AU - Leśko, Marek AU - Samuelsson, Jörgen AU - Åsberg, Dennis AU - Kaczmarski, Krzysztof AU - Fornstedt, Torgny T2 - Journal of Chromatography A AB - In recent studies, the nature and magnitude of the temperature gradients developed in ultra-high pressure liquid chromatography (UHPLC), were found to be dependent on the heat conductivity properties of the column matrices, but also, on the principle used for controlling the temperature over the column. Here, we investigated the potential of using highly heat conductive diamond-based stationary phases (85 times higher than silica), for reducing the temperature gradients. The stationary phases investigated were a (i) Diamond Analytics FLARE column, based on particles comprising of a graphite core surrounded by a very thin diamond shell, and two silica hybrid columns: (ii) a core-shell silica Kromasil Eternity Shell column and (iii) a fully porous silica Kromasil Eternity XT column. Models were developed based on two-dimensional heat transfer theory and mass transfer theory, which were used to model the temperature profiles and the migration of a compound band accounting for column efficiencies at different flow rates. For the silica-based columns, using water-controlled temperature mode, the temperature gradients along the column axes are suppressed whereas temperature gradients in the radial direction prevails resulting in decreased column efficiencies. Using these columns with air-controlled temperature mode, the radial temperature gradients are reduced whereas temperature gradients along the column prevails resulting in decreased retention times. With the Diamond FLARE column, there was no loss in column efficiency using the water-controlled temperature mode and the van Deemter curves are almost identical using both temperature control modes. Thus, for the Diamond FLARE column, in contrast to the silica-based columns, there are more or less no losses of column efficiencies due to reduced radial temperature gradients independent on how the column temperature was controlled. DA - 2020/04/03/ PY - 2020 DO - 10.1016/j.chroma.2020.461076 DP - ScienceDirect SP - 461076 J2 - Journal of Chromatography A LA - en SN - 0021-9673 UR - http://www.sciencedirect.com/science/article/pii/S0021967320302971 Y2 - 2020/04/04/13:17:01 KW - Column performance KW - Core-shell particles KW - Diamond FLARE column KW - Temperature control KW - Temperature gradient KW - Viscous heating ER -