Retention behaviour of polar peptides at high aqueous content mobile phases on a silica hydride phase — ASN Events

Retention behaviour of polar peptides at high aqueous content mobile phases on a silica hydride phase (#260)

Chadin Kulsing 1 , Reinhard I. Boysen 1 , Yuanzhong Yang 1 , Maria T. Matyska 2 , Joseph J. Pesek 2 , Milton T.W. Hearn 1
  1. School of Chemistry, Monash University, Melbourne, VIC, Australia
  2. Department of Chemistry, San Jose State University, San Jose, CA, USA

The demands of greater process productivity and sustainability in the chemical, pharmaceutical and biotechnological industries are driving the development of new separation materials with improved selectivity, higher resolution, faster speed, and enhanced pre-concentration/sample handling capabilities. Our recent work has focused on the synthesis and evaluation of several new classes of stationary phase materials that enable these objectives to be achieved. Here, the application of a new concept is explored – aqueous normal phase chromatography (ANPC) based on silica hydride stationary phases – for the separation of polar peptides under high aqueous mobile phase conditions [1], [2].

The retention behaviour of polar peptides separated on a silica hydride phase was examined with a capillary HPLC and ESI-MS detection. The effects on peptide retention of two acidic buffer additives (formic acid and acetic acid) and their concentrations in the mobile phase consisting of acetonitrile/water mixtures with the acetonitrile content ranging from 5%-80% (v/v) were systematically investigated. Strong retention of the peptides was observed with relatively high-organic low-aqueous mobile phases (i.e., under ANPC conditions). However, when low concentrations of acetic acid were employed as the buffer additive, strong retention of the peptides was also observed even when high aqueous content mobile phases were employed. This unique feature of the silica hydride phase therefore provides an opportunity for chromatographic analysis of polar peptides with water-rich eluents, a feature usually not feasible with traditional reversed-phase sorbents, and thus under conditions more compatible with analytical green chemistry criteria. Dipolarity- and hydrogen bonding-type interactions between the peptides in aquo-organic mobile phases with varying organic modifier content and mobile phase additives and the stationary phase were analysed based on the concept of linear solvation energy relationship.

Collectively, these approaches and new separation materials are expected to be valuable additions to the chromatographic toolkit for use in various fields of separation.

  1. Boysen, R.I., Yang, Y., Chowdhury, J., Matyska, M.T., Pesek, J.J. and Hearn, M.T.W. (2011) Journal of Chromatography A 1218(44), 8021-8026.
  2. Yang, Y., Boysen, R.I., Kulsing, C., Matyska, M.T., Pesek, J.J. and Hearn, M.T.W. (2013) Journal of Separation Science, in press.