示波滴定法测定脒甲异脲与氨基均三嗪

Determination of Guanyl-o-Methylisourea and 2-Amino -4-Methoxy-6-Methyl-s-Triazine by Oscillo-graphic Titration

脒甲异脲盐酸盐为第四胺化合物，氨基均三嗪可经浓硫醚消解处理成铵盐，它们均可与四苯硼钠定量反应。在ｐＨ＝５的条件下以过量四苯硼钠沉淀试样，干过滤后，吸取部分滤液用Ｔｌ＿２ＳＯ＿４为反滴定剂，以ＮａＡｃ－ＮａＯＨ为底液，汞膜电极为指示电极，钨电极为参比电极进行示波滴定。由示波图上ＴＰＢ￣－切口的消失指示滴定终点。此法简便、灵敏、准确，测定结果今人满意。

Guanyl-o-methylisourea and 2-amino-4-methoxy-6-methyl-s-triazine are organic compounds containingnitrogen,which can be determined by oscillographictitration method.In this paper NaTPB is used as theprecipitant and Tl_2SO_4 as the back titrant.Satisfactoryresults can be obtained by taking the disappearence ofincision of TPB￣- as the end-point of titration.