中国药典(1990年版二部)异烟肼及其片剂含量测定.采用溴酸钾滴定,乙氨基黄叱精为指示剂。由于该指示剂价昂且不易购得,应用有一定的困难。为此,我们参考有关资料,改用甲基橙为指示剂,它不仅易得,且终点由红色变为无色较乙氧基黄叱精终点由红色变为淡黄色易于观察,突跃明显。经实验,测得结果与用乙氧基黄叱精指示剂完 Determination of isoniazid and its tablet in Chinese Pharmacopoeia (1990 edition) .By using potassium bromate titration, ethylamidin as indicator. Due to the fact that the indicator is too expensive to be purchased, there is some difficulty in its application. To this end, we refer to the relevant information, the use of methyl orange as an indicator, it is not only easy to get, and the end point from red to colorless than ethoxyglonicum end point from red to light yellow easy to observe, sudden jump obvious . The experiment, the measured results and the use of ethoxy gufen precision indicator finished