Selectivity differences for C18 and C8 reversed-phase columns as a function of temperature and gradient steepness II.: Minimizing column reproducibility problems

The choice of T and t(G) as variables for controlling selectivity and resolution during reversed-phase liquid chromatography (RPLC) method development can be used to minimize problems caused by column batch-to-batch irreproducibility. When a new column fails to provide adequate separation of the sample, altered values of T and t(G) can be predicted that will restore the separation obtained with the previous column. Alternatively, columns from different manufacturers can be tested during method development, in order to find a common set of conditions (T and t(G)) that provide acceptable separation with two or more of these columns. In this way, any of several columns from different sources become usable for the method. Examples are shown of these different computer-assisted procedures for minimizing problems due to column variability. (C) 2000 Elsevier Science B.V. All rights reserved.