Effect of radial thermal gradients in elevated temperature high-performance liquid chromatography

Detection Modes with High Temperature Liquid Chromatography—A Review

“…In absence of preheating, the mobile phase entering in the column is not at the oven temperature, involving radial and axial temperature gradients (46,47). .…”

“…Many concepts were proposed to carry out separations in isothermal mode; they are listed in a recent review (53). They consist either of using a relatively long tubing length placed inside an oven between the injector and the column inlet (15,46), or a short tubing length in contact with a powerful heating block (47,54).…”

Pressure dependence of diffusion coefficient and effect on plate height in liquid chromatography

“…The time standard deviation, of the peak , at the column outlet, is related to the standard deviation in distance units along the column at z = L, assuming that the solvent velocity is constant all along the column, that is, neglecting its very small variations due to the solvent compressibility coefficient of relative variation of the reciprocal of the diffusion coefficient with pressure (eq 7) a" coefficient of relative variation of the viscosity with pressure (eq 5) ß limiting value, at low pressure, of the pressure drop leading to a unit increase of the reduced velocity (eq 30) Ah difference between the apparent reduced plate height and the reduced plate height at column outlet (eq 35) AP0…”

A linearized non-isothermal general rate model for studying thermal effects in liquid chromatographic columns

“…Literature review for the past decade shows that interest in the use of HTLC has gained momentum principally as a way to increase the speed of LC analysis and to modify chromatographic selectivity, see [5]. Several experimental studies have been conducted to study temperature variations inside the column and their consequent on the chromatographic process, see [6][7][8][9][10]. Thermal effects in gas chromatography were also analyzed and reported by several authors, see [11][12][13][14][15].…”