A continuous-flow instrument for the determination of linear polyacrylamide stability

Alkaline hydrolysis of high-molecular-mass (10 MDa) linear polyacrylamide, a widely used replaceable sieving medium for the capillary electrophoresis of DNA fragments and proteins, was investigated. The release rate of ammonia, a product of amide group hydrolysis, was monitored by a high-sensitivity continuous-flow system. The experimental results show a rapid onset of hydrolysis at a temperature of 70 degrees C. While the degree of 1 h hydrolysis was evaluated to reach about 16% at 70 degrees C and pH 13, it drops to 5% at 50 degrees C and pH 12.5.