Efforts to eliminate solute-silanol interactions have recently lead to big advancements in sorbent chemistry.  While "secondary" effects can be vital for obtaining desired selectivity in some applications, they rarely help when polar amines are being analyzed.

Higgins' new TARGA columns are true to the Latin root of their name.  Targa, meaning "sheild," is precisely the effect the unique bonded phase has on the silica's silanol surface.

Many HPLC column manufacturers illustrate the performance of their columns packed with inert, base deactivated, "Type B silica" bonded phases by the chromatographic behavior of polar compounds such as pyridine.  Performance claims can be misleading, however, when mobile phases are buffered to low pH or when they contain high percentages of organic solvent.

A more revealing test for solute-silanol interaction is to use a mobile phase containing a relatively low amount of organic solvent and no additives or buffers.  Compared to two popular HPLC columns, whose manufacturers claim have a high degree of inertness, the TARGA C18 column exhibits very good efficiency and symmetry for pyridine.

More Targa product information is in HAINEWS #5

Other TARGA Chromatograms:

Fat-soluble vitamin assay	Microbore tryptic map of myoglobin without TFA	Microbore tryptic map of cytochrome C without TFA
Unbuffered pyridine and phenol on Targa C18 5µm	Basic   peptides without TFA 0.1% acetic acid, pH 3.1 215nm	Nucleotides 15mM Ammonium acetate, pH 6.0, 0% to 10% MeOH, Targa C18 5µm 260nm