Figure 2From: Facile spectrophotometric assay of molar equivalents of N-hydroxysuccinimide esters of monomethoxyl poly-(ethylene glycol) derivatives Reaction process of TNBS with tested primary amines at room temperature. Final concentration of each primary amine was 100 μmol/L for reaction with TNBS. Absorbance at 420 nm was measured at indicated periods with a proper reagent blank.Back to article page