Comprehensive Study on the Optimization of Online Two-Dimensional Liquid Chromatographic Systems Considering Losses in Theoretical Peak Capacity in First- and Second-Dimensions: A Pareto-Optimality Approach

摘要

A method to optimize different objectives (total analysisntime, total peak capacity, and total dilution) has beennapplied to comprehensive two-dimensional liquid chromatography.nThe approach is based on Pareto-optimality,nand it yields optimal parameters (column particle sizes,ncolumn diameters, and modulation times). Losses in thenpeak capacities in the first dimension (due to undersampling)nand in the second dimension (due to high injectionnvolumes) have been taken into account. The first effectn(detection band broadening) reduces the original peakncapacity by about a half, the second effect can reduce thentotal peak capacity by an additional half. Thus, the totalnloss in peak capacity may be 75% of its theoretical value.nAnalytical expressions to calculate these effects underngradient and isocratic conditions are derived. Of particularninterest is the study of the optimal modulation times,nwhich corresponded to between 2 and 3 two-dimensionalnruns per one-dimensional peak. The effects of usingngradient or isocratic elution, conventional (40 MPa) orn“ultra-high” (100 MPa) pressures, and focusing betweennthe first and second dimensions were also studied. Antrade-off between total peak capacity, total analysis time,nand total dilution can be established.