Targeted isolations from complex samples using two-dimensional HPLC. Part 2 : a semi-continuous heart cutting mode

The experimental parameters that affected the preparative isolation of the target component at low sample loading were investigated. The experimental variables were interconnected; when one variable was optimized it had a detrimental effect on another variable. Impurities that eluted close to the target component also placed constraints on optimization parameters, such as, production rate, product recovery yield, and purity. Overall, the practical production rate was maximized (0.058mg/h/L) when the recovery was maximized; however, this resulted in the lowest product purity (14%): Maximized purity (93%) resulted in the lowest production rate (0.025mg/h/L). The findings in this study were, however, restricted to low sample loads. A consequence of which was that the first dimension was operated essentially under analytical conditions and the potential to load the first dimension column with sufficient sample was not reached.