title: A simple spectrophotometric determination of solid supported amino groups.
abstract: A simple spectrophotometric method for the quantitative determination of solid phase supported amino groups is described. The method involves reacting the solid support with an excess of activated acylating agent, N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) and an efficient acylation catalyst, 4-dimethylaminopyridine, and after thoroughly removing the unreacted SPDP, the solid support is reacted with an excess of dithiothreitol to quantitatively release pyridine-2-thione from the solid support to the solution. After an appropriate dilution, the released pyridine-2-thione which has a strong absorbance at 343 nm, is quantified by reading its absorbance in a spectrophotometer at 343 nm.
mesh_terms: D015761:4-Aminopyridine / Q000031:analogs & derivatives*; D000588:Amines / Q000032:analysis*; D000631:Aminopyridines; D004229:Dithiothreitol; D007202:Indicators and Reagents; D011725:Pyridines / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013388:Succinimides
chemical_list: D000588:Amines; D000631:Aminopyridines; D007202:Indicators and Reagents; D011725:Pyridines; D013388:Succinimides; C018151:N-succinimidyl 3-(2-pyridyldithio)propionate; D015761:4-Aminopyridine; C029347:2-thiopyridine; C003885:4-dimethylaminopyridine; D004229:Dithiothreitol