Extreme SFC/MS: Elution and characterization of peptides up to 40-mers in length

ANYL 11

Jun Zheng, sally.zheng@abbott.com1, J. David Pinkston, pinkston.jd@pg.com2, Paul H. Zoutendam2, and Larry T. Taylor, ltaylor@vt.edu3. (1) Abbott Laboratories, R4CP, AP9B, 100 Abbott Park Rd., Abbott, IL 60064-6113, (2) Procter and Gamble Pharmaceuticals, Health Care Research Center, 8700 Mason-Montgomery Road, P.O. Box 8006, Mason, OH 45040, (3) Department of Chemistry, Virginia Tech, 107 Davidson Hall, Blacksburg, VA 24061
SFC provides a number of advantages over traditional reversed-phase HPLC such as speed, practical use of longer columns, a normal-phase retention mechanism, reduced use of organic solvents, and reduced generation of aqueous-organic waste. But SFC has traditionally been limited to relatively nonpolar compounds because of the nonpolar nature of the major component of most SFC mobile phases, CO2. For example, the advantages of SFC and SFC/MS have not been applied to peptides, except in the case of the smallest, most hydrophobic peptides. The characterization of peptides is critically important for drug discovery and development in the pharmaceutical industry, as well as for a variety of other important applications, and the advantages of SFC and SFC/MS would be welcome in these areas. We've recently shown that relatively large peptides (at least 40 mers, molecular mass of over 4500 Da), containing a variety of acidic and basic residues, and covering the full range of peptide hydrophobicities, can be characterized using SFC/MS. The most successful method for the largest peptides used an ethylpyridine bonded phase on silica, and a modifier consisting of 13 mM trifluoroacetic acid in methanol. We're currently exploring the limits of the method.