Evaluation of the Use of Lithium Nitrate as a Test Substance for the Determination of the Hold-Up Time of a Reversed-Phase Packing

Abstract

The use of lithium nitrate as a test substance for the determination of the hold-up time on μ Bondapak C18 columns has been evaluated by comparison with the hold-up time calculated with the homologous series of n-alcohols. The influence of charge exclusion effects on the retention time of lithium nitrate is investigated. The addition of phosphoric acid to the eluent appears to be an effective method to reduce charge exclusion effects. The existence of deviations from linearity are demonstrated for the homologous series of n-alcohols in eluents with a low methanol content.