A new method of spectrophotometric determination of poly(diallyldimethylammonium chloride) concentration

摘要

Spectrophotometric method of protein determination, widely known as the Bradford method, has been applied for quantitative determination of poly(diallyldimethylammonium chloride) (PDDA) monomer units in aqueous solution. In phosphoric acid environment the PDDA polymer stabilizes blue form of the Commasie Briliant Blue G-250 dye having a broad absorption band. Increase in absorbance at wavelengths in the range from 570 to 630 nm follows the increase in monomer units of polymer concentration up to 0.042 mmole/dm~3. Calibration curves fulfilling second-degree polynomial equations can be determined for PDDA monomer units concentrations not exceeding 0.03 mmole/dm~3.