title: Spectrophotometric method for the quantitative assay of N-hydroxysulfosuccinimide esters including extinction coefficients and reaction kinetics.
abstract: A quantitative spectrophotometric method has been developed for the analysis of N-hydroxysulfosuccinimide (sulfo-NHS), a chromophore with a maximum absorbance at 268 nm. The extinction coefficients were determined between pH 6.0 and 8.0 and found to vary in a nonlinear manner. This spectrophotometric profile is not present in its esters which however release an equimolar amount of sulfo-NHS when they react with nucleophilic groups or hydrolyze in aqueous solution. This fact facilitates the determination in solution of the concentration and purity of bis(sulfosuccinimidyl) suberate (BS3) used as a model, as well as the examination of hydrolysis and aminolysis half-lives in different reaction conditions, these parameters being valuable in optimization of the use of the active esters.
authors.affiliation: Sclavo Diagnostics International Srl, Italy. Electronic address: rivo.presentini@tin.it.
authors.forename: Rivo
authors.initials: R
authors.lastname: Presentini
mesh_terms: D001681:Biological Assay / Q000379:methods*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004952:Esters / Q000032:analysis*; D006868:Hydrolysis; D007700:Kinetics; D013053:Spectrophotometry / Q000379:methods*; D013388:Succinimides / Q000032:analysis*
chemical_list: D003432:Cross-Linking Reagents; D004952:Esters; D013388:Succinimides; C035761:N-hydroxysulfosuccinimide
keywords: Aminolysis half-life; Hydrolysis half-life; Molar extinction coefficients; N-hydroxysulfosuccinimide; N-hydroxysulfosuccinimide esters; Spectrophotometric method