title: Using the column wall itself as resistive heater for fast temperature gradients in liquid chromatography.
abstract: A new system is proposed for applying fast temperature gradients in liquid chromatography. It consists of a 0.7 mm × 150 mm fused-silica column coated with a 50 μm Nickel-layer, which is connecting with a power source and a temperature control system to perform fast and reproducible temperature gradients using the column wall itself as a resistive heater. Applying a current of 4A and passive cooling results in a maximal heating and cooling rate of, respectively, 71 and -21 °C/min. Multi-segment temperature gradients were superimposed on mobile phase gradients to enhance the selectivity for three sets of mixtures (pharmaceutical compounds, a highly complex mixture and an insecticide sample). This resulted in a higher peak count or better selectivities for the various mixtures.
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering (CHIS-IR), Pleinlaan 2, 1050 Brussels, Belgium.
authors.forename: Ruben
authors.initials: R
authors.lastname: De Pauw
authors.affiliation: Dow Stade Produktions GmbH, Analytical Technology Center, 21677 Stade, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Pursch
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering (CHIS-IR), Pleinlaan 2, 1050 Brussels, Belgium. Electronic address: gedesmet@vub.ac.be.
authors.forename: Gert
authors.initials: G
authors.lastname: Desmet
mesh_terms: D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000379:methods*; D045424:Complex Mixtures / Q000302:isolation & purification*; D006361:Heating; D007306:Insecticides / Q000302:isolation & purification*; D009532:Nickel / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000302:isolation & purification*; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature
chemical_list: D045424:Complex Mixtures; D007306:Insecticides; D004364:Pharmaceutical Preparations; D012822:Silicon Dioxide; D009532:Nickel
keywords: Liquid chromatography; Low thermal mass; Resistive heating; Selectivity; Temperature gradient