Determination of Trifluoroacetic Acid (TFA) in Peptides

Application Note 160 Determination of Residual Trifluoroacetate in Protein Purification Buffers and Peptide Preparations by Reagent-Free™ Ion Chromatography INTRODUCTION EQUIPMENT A Reagent-Free ion chromatography (RFIC) system allows the determination of anions or cations with only the addition of deionized water.…

Application Note 116 Quantification of Anions in Pharmaceuticals INTRODUCTION The United States Food and Drug Administration (U.S. FDA)1–3 and regulatory agencies in other countries require that pharmaceutical products be tested for composition to verify their identity, strength, quality, and purity,…

Technical Note 50 Determination of the Amino Acid Content of Peptides by AAA-Direct INTRODUCTION EQUIPMENT ™ The AAA-Direct system separates amino acids on a high performance anion-exchange column and directly detects them by integrated amperometry.1, 2 AAA-Direct has advantages over…

Application Note 130 Identification of a Hydroxylysine-Containing Peptide Using AAA-Direct™ INTRODUCTION One type of protein microheterogeneity is a result of the posttranslational modification of lysine (Lys) to hydroxylysine (Hyl). This modification normally occurs in collagen and a few other proteins…