The result was a new phase that allows for chromatographic separations without interference by protein adsorption. The efficacy of the GFF II phases has been demonstrated in a variety of applications, including the study of drugs, their metabolites, and the resolution of peptides. L-phenylalanine tripeptide bonded within the silica pores. GFF was chosen from many available peptides for its selectivity towards positively charged aromatic analytes and a variety of neutral molecules. The hydrophilic outer surface, created from the cleavage of the original tripeptide, is comprised of the single amino acid, glycine.
Modifiers can include acetonitrile, methanol, isopropanol, and tetrahydrofuran.
The pH of the mobile phase can be controlled to avoid protein denaturing and to enhance selectivity. As a result, negatively charged proteins are repulsed by the outer phase, and pass quickly through the column. Separations can also be optimized by varying column temperature. Lower temperatures have been shown to result in increased retention and selectivity. ISRP GFF and GFF II Analytical Columns Product Particle Size Column Length and i.d.