Quantitation of polyhexamethylene biguanide by photometric titration with Naphthol Blue Black dye (in English)
Polimery 2014, No 2, 160
A convenient and reliable method for quantitative determination of polyhexamethylene biguanide in aqueous solutions has been developed, based on complexation of the polymer with Naphthol Blue Black dye. Spectrophotometric titration measuring absorbance at 600 nm leads to characteristic zigzag curves, with the inflexion point at dye to polymer mers molar ratio 1:2. The photometric titration endpoints are characterized with good repeatability, resulting in low variance values. As a result, the limit of polyhexamethylene biguanide determination has been found to be equal to 50 and 150 µmol/dm3 of mers for direct and reverse titration, respectively.