Abstract Potentiometric titration is employed in the national standard to measure the content of amino acid nitrogen in soy sauces for quality assessment, the method has the advantages of public availability of the instruments and easy operation. However, there are some difficulties in implementing this method in a fundamental teaching laboratory, such as small consumption volume of sodium hydroxide titrant that leads to poor accuracy and long blank calibration time using ordinary pH glass electrode. In this paper, the standard method is modified according to the apparatus available in the fundamental teaching laboratory, with the merits of shorter measuring time and enhanced accuracy and precision. Introducing national standards into undergraduate laboratory experiments can stimulate students' interests in learning, cultivate rigorous and meticulous operation habits, improve the ability of knowledge application, and promote the cultivation of innovative talents.
TANG Zhan-Qiu, QIN Wei-Dong. Modification and Application of the National Standard Method in Undergraduate Laboratory Experiment for Determining Amino Acid Nitrogen in Soy Sauce[J]. Chinese Journal of Chemical Education, 2023, 44(20): 50-53.
