Characterization of reversed-phase liquid chromatographic columns containing positively charged functionality.

To date, the most commonly used column characterization databases do not determine the relative positive charge associated with new generation RP columns, or they fail to successfully discriminate between RP columns of purportedly low level positive and neutral characters. This paper rectifies this in that it describes a convenient and robust chromatographic procedure for the assessment of the low levels of positive charge on a range of RP columns. The low degree of positive charge was determined by their electrostatic attraction towards the negatively charged 4-n-octylbenzene sulfonic acid (4-OBSA) relative to their retention of the hydrophobic marker toluene (Tol).