High temperature and temperature programming in high-performance liquid chromatography: Instrumental considerations

Temperature as a Variable in Pharmaceutical Applications

“…Temperatures above 80°C, where pressure has to be applied to prevent the mobile phase from boiling, are usually termed either pressurized, superheated, or subcritical conditions, the latter two terms being more frequently applied to separations with just water as the mobile phase. Either the separations can be isothermal or a temperature gradient can be employed, which generates an effect similar to gradient elution, speeding up the later components [19,20]. However, concern is often expressed that the mass of a packed HPLC column might cause the internal temperature to lag behind the oven setting but as long as the internal temperature is reproducible, a valid method can be developed.…”

“…However, concern is often expressed that the mass of a packed HPLC column might cause the internal temperature to lag behind the oven setting but as long as the internal temperature is reproducible, a valid method can be developed. A number of early studies employed packed capillary columns with a low thermal mass [19].…”

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). .…”

Temperature programming in liquid chromatography

“…With standard size LC columns, preheating the mobile phase improved the system performance by reducing the temperature lag between the set and the actual temperature [54]. With narrow-bore columns, preheating does not appear to be important, due to the low thermal mass of the columns.…”