ABSTRACT
High-performance liquid chromatography (HPLC) emerged as an important analytical technique around 1972, when it became possible to pack columns with particles of diameter less than 30 µm [1-3]. Commercial 10 µm columns became available in 1973 [4]. Now, for the rst time, column performance was suitable for the wide range of applications that HPLC enjoys today. Very quickly, researchers explored smaller and smaller particle sizes [5] and encountered what appeared to be the frontier of the new technology [6,7]: the pressure-induced heat of friction inside a chromatographic column results in a signicant increase in the temperature of the mobile phase. This effect is tolerable at pressures below 400 bar, and the technology of HPLC evolved happily and successfully below this apparent limit. Particle sizes decreased slowly, and the speed of analysis improved as the analytical demands increased. However, the thermal effects appeared to impose a permanent limit on the technology.
