High speed liquid chromatography with small bore columns

Using a specially designed column system, we have systematically investigated the effect of mobile phase velocity on column efficiency. The performance of small bore columns operated at different linear velocities of mobile phase was examined for three different types of injection system. Using the value of H^∞/u or n^∞/t${}_{\text{r}}^{\text{º}}$ as a criterion of a high speed separation, we calculated values of n/t${}_{\text{r}}^{\text{º}}$ for different solutes according to the equation documentclass{article}pagestyle{empty}begin{document}$ {{rm n}mathord{left/ {vphantom {{rm n} {{rm t}_{rm r}^ circ }}}right. kern-nulldelimiterspace} {{rm t}_{rm r}^ circ }} = {{{rm n}^infty } mathord{left/ {vphantom {{{rm n}^infty } {{rm t}_{rm r}^ circ }}} right. kern-nulldelimiterspace} {{rm t}_{rm r}^ circ }}left({frac{{1 + {rm k'}}}{{{rm k' + }beta }}} right)^2 $end{document}; the results obtained are in agreement with the experimentally determined values. These systematic investigations culminated in the separation of seven compounds in less than 10 s; the respective chromatogram is shown.