Spectrophotometric Determination of Substrate-Borne Polyacrylamide

• Published in: Journal of agricultural and food chemistry Vol. 50; no. 18; pp. 5038 - 5041
• Main Authors: Lu, Jianhang, Wu, Laosheng
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 28-08-2002
• Subjects: Acrylic Resins - analysis; Agronomy. Soil science and plant productions; Biological and medical sciences; Bromine - chemistry; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Generalities; Indicators and Reagents; Iodides; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Reproducibility of Results; Sensitivity and Specificity; Soil - analysis; Soil science; Solutions; Spectrophotometry; Starch; Water; Clay; Organic matter; Sand; Triiodides; Starch; Bromination; Cellulose; Organomineral complex; Calibration; Burnt soil; Acrylamide polymer; Measurement method; Measurement accuracy; Aqueous solution; Spectrophotometry
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf025528x

Polyacrylamides (PAMs) have wide application in many industries and in agriculture. Scientific research and industrial applications manifested a need for a method that can quantify substrate-borne PAM. The N-bromination method (a PAM analytical technique based on N-bromination of amide groups and spectrophotometric determination of the formed starch−triiodide complex), which was originally developed for determining PAM in aqueous solutions, was modified to quantify substrate-borne PAM. In the modified method, the quantity of substrate-borne PAM was converted to a concentration of starch−triiodide complex in aqueous solution that was then measured by spectrophotometry. The method sensitivity varied with substrates due to sorption of reagents and reaction intermediates on the substrates. Therefore, separate calibration for each substrate was required. Results from PAM samples in sand, cellulose, organic matter burnt soils, and clay minerals showed that this method had good accuracy and reproducibility. The PAM recoveries ranged from 95.8% to 103.7%, and the relative standard deviations (n = 4) were <7.5% in all cases. The optimum range of PAM in each sample is 10−80 μg. The technique can serve as an effective tool in improving PAM application and facilitating PAM-related research. Keywords: Substrate-Borne Polyacrylamide; N-bromination method; spectrophotometric determination