用1，10－二氮杂菲分光光度法测定沉淀法白炭黑中的铁含量

Determination of iron Content in Precipitated Silica with 1, 10-Phenathrinediazine Spectraphotometry

提出并研究了使用１，１０－二氮杂菲分光光度法测定沉淀法白炭黑中铁含量的分析方法。其具体步骤为：首先用氢氟酸处理试样，使沉淀法白炭黑（二氧化硅）转化成四氟化硅气体逸出。而后在ｐＨ为４～５条件下，用盐酸羟胺处理剂将残留液中的三价铁离子还原成二价铁离子，加入１，１０－二氮杂菲显色剂（与二价铁离子反应可生成橙红色络合物），再用分光光度法测定其中的铁含量。实验表明，本方法原理可靠，分析步骤简便，抗铜、锰离子干扰性强，精密度与准确度较高。

An analytical method is proposed and studied for determination of the iron content in precipitated silica with 1, 10-Phenathrinediazine Spectraphotometry. Its specific procedures are :first to treat the sample with hydrofluoric acid to convert the silica into a gas of silicon tetrafluoride to escape, and then at a PH value of 4 to 5 to treat the residual liquid with hydroxylamine hydrochloride to get the ferric ions reduced to ferrous ions. By the addition of 1, 10-phenathrinediazine which reacts with the ferrous ions to produce an orange red complex compound, the iron content therein can be determined by the use of visible photometry. Experiments show that the method is reliable in principle, simple in procedure and functions well against the interference by copper and manganese ions, and also it proves to be good in precision and accuracy.