The Thermo Scientific HPLC system is applied for the analysis of sigma peptide standard with TFA as the mobile phase modifier. The separation is performed on a Thermo Scientific Acclaim 300 C18 HPLC column, with UV detection at 214 nm. Trifluoroacetic acid (TFA) is used as a mobile phase modifier in peptide analysis because it promotes efficient peak shape, in part by suppressing interactions with silanols on the column.
The Thermo Scientific HPLC system is applied for the comparison of the selectivity for sigma peptide standard with TFA vs formic acid. The separation is performed on a Thermo Scientific Acclaim 300 C18 HPLC column, with UV detection at 214 nm. Formic acid is a weaker acid, and a weaker ion-pairing agent, but gives a stronger signal for electrospray mass spectrometric detection. TFA is a better ion-pairing agent and yields better efficiency, but at the expense of MS performance.
The Thermo Scientific HPLC system is applied for the analysis of angiotensins. The separation is performed on a Thermo Scientific Hypersil GOLD HPLC column, with UV detection at 230 nm.
