Improvement and verification of alkalinity determination method of surfactant

The alkalinity of surfactant is detected mainly according to the method in the national standard GB / T 7378-1996, using manual titration and judging the titration end point according to the indicator. In this paper, the national standard method was improved and verified based on the automatic potentiometric titrator. The photometric titration and potentiometric titration for the determination of surfactant alkalinity were established and verified. The improved method judges the titration end point according to the jump points of photometric electrode and potential electrode, respectively. The end point judgment was more accurate, the evaluation of the consistency with the results of the national standard method was ideal, and the RSD values of the repeatability evaluation results were no more than 3. 0% . The improved photometric titration and potentiometric titration methods based on the national standard method have accurate titration volume control, high degree of automation, good repeatability and accuracy, and can be used as the improved method for practical detection. © 2021, Youke Publishing Co.,Ltd. All rights reserved.