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盐酸麻黄碱的医院制剂快速定量方法,一般多采用中和法,但滴定时所用有机溶剂,在种类和用量上各不相同,测定结果亦不一致。为此,我们对各法进行了实验比较。方法方法一 (乙醚为溶剂) 精密吸取准确配制的1％的盐酸麻黄碱溶液5ml,加入不同体积的乙醚,再加酚酞指示液及麝香草酚兰指示液各三滴,在充分振摇下,用氢氧化钠液(0.1mol/L)滴定至水层呈紫色。对于滴定终点的紫色,因其色调深浅不一,故又同时作了浅紫色和深紫色(偏红)的两组实验比较。讨论与小结 1、以Gran作图法确定等当点时电位法适用于一般的容量分析中由于滴定突跃太小而使终点难于观察的滴定反应。对于任何中和滴定,只要用本法测定,就能很容易地找到等当点。
Ephedrine hydrochloride rapid preparation of hospital methods, the general use of neutralization method, but the titration of the organic solvent used in the type and amount of different, the measured results are inconsistent. For this reason, we have carried on the experiment comparison to each law. Method A (ether as the solvent) Precision drawing 1% of the ephedrine hydrochloride solution accurately formulated 5ml, add different volumes of ether, add phenolphthalein indicator solution and thymol blue indicator solution three drops each, under full shaking, Titration with sodium hydroxide solution (0.1mol / L) until the water layer is purple. For the end of the titration of purple, because of its shades vary, it also made a light purple and dark purple (reddish) two sets of experimental comparison. Discussion and Summary 1, Gran graph to determine equivalence point potential method applied to the general volumetric analysis due to titration jump is too small and difficult to observe the end of the titration reaction. For any neutralization titration, as long as the use of this method, you can easily find the equivalent point.