Spectrophotometric determination of substrate-borne polyacrylamide

Area of Science:

• Analytical Chemistry
• Environmental Science
• Polymer Science

Background:

• Polyacrylamides (PAMs) are widely used in industry and agriculture.
• Quantifying substrate-borne PAM is essential for research and application optimization.
• Existing methods for PAM determination are limited, especially for solid matrices.

Purpose of the Study:

• To modify and validate the N-bromination method for quantifying substrate-borne polyacrylamides (PAMs).
• To assess the accuracy, reproducibility, and limitations of the modified method across different substrates.

Main Methods:

• Modification of the N-bromination method, originally for aqueous PAM, to analyze substrate-bound PAM.
• Conversion of substrate-borne PAM to an aqueous starch-triiodide complex for spectrophotometric measurement.
• Substrate-specific calibration to account for variations in reagent sorption and reaction.

Main Results:

• The modified N-bromination method demonstrated good accuracy and reproducibility for PAM quantification in sand, cellulose, burnt soils, and clay minerals.
• PAM recoveries ranged from 95.8% to 103.7% with relative standard deviations below 7.5% (n=4).
• Method sensitivity is influenced by substrate type, necessitating individual calibration; optimal PAM range is 10-80 µg.

Conclusions:

• The modified N-bromination technique provides an effective and reliable tool for quantifying substrate-borne polyacrylamides.
• This method can enhance the precision of PAM application strategies and support further PAM-related scientific investigations.
• Accurate quantification of PAM on diverse substrates is vital for environmental and industrial applications.