Problems of the interlaboratory transferability of the measurement of the properties of a reversed-phase HPLC column

The reproducible transferability of HPLC methods between laboratories requires careful specification of the method, especially the temperature control of the column. The methods were examined in two international collaborative studies for a series of column characterisation tests for ODS-bonded phase columns. The results from 16 laboratories in the first study and 7 laboratories in the second study are analysed. Differences in the type of column oven can cause significant differences in the effective column temperature and hence in the relative retention times used to calculate hydrophobicity and shape selectivity Water bath or water jackets gave markedly different results to air ovens at the same nominal temperature and were recommended as providing more transferable results. However, although the incoming eluent was controlled to be at the column temperature the efficiency of the separations were lower than in an air bath oven but were more repeatable.