摘要
用甲醛法测定酱油中的氨基氮时,常用酚酞为指示剂确定终点,效果不佳.本法改用酚酞-溴百里酚蓝混合指示剂来确定滴定终点,其变色锐敏、重现性好、准确度高.
Phenolphthalein is often used as indicator in order to determine the terminal point of titration during measuring the content of amino nitrogen in soy sauce by formaldehyde method. But the result isn't satisfactory. The authors applied mixed indicator of phenolphthalein and dibromothymolsulfonphthalc to deter-mine the terminal point of titration. The results show that the method has a high sensitivity of the colour change and the accuracy and the properties of reappearance both are excellent.
出处
《西南师范大学学报（自然科学版）》
CAS
CSCD
1991年第3期345-348,共4页
Journal of Southwest China Normal University(Natural Science Edition)
关键词
酱油
氨基氮
测定
甲醛法
酚酞
formaldehyde
phenolphthalein
dibromothymolsul fonphthalein
