硝酸胍的单点滴定法快速分析

Rapid Determination of Guanidine Nitrate by Single _ point Titration

报道了以Ｓ－ 十二烷基双硫腙－ 苦味酸为载体制备苦味酸根离子电极， 研究了电极的性能， 并以该电极为指示电极研究了硝酸胍的单点滴定分析， 导出了定量关系式。 以０ ．１００ ０ ｍｏｌ／ Ｌ 标准硝酸胍溶液滴定０ ．１００ ０ ｍｏｌ／Ｌ 苦味酸， 控制滴定至９５ ％ ，１０ 次实验的平均值为０ ．１００ ２ ｍｏｌ／Ｌ， 相对标准偏差为０ ．２４ ％ ， 滴定至９０％ ～９５ ％ 相对标准偏差小于０ ．３ ％ 。 用该法进行工业硝酸胍含量分析， 数分钟就能完成， 结果与重量法很好吻合。

Preparation of a picrate _ selective electrode with a new carrier consisting of S _ dodecyl diphenylthiocarbazone and picric acid is reported. The characteristics of the electrode have been studied. The single _ point titration of guanidine nitrate was conducted with this electrode as the indicating electrode. A quantitative equation was derived. When a picric acid solution of 0.100 0 mol·L-1 was titrated with a standard solution of 0.100 0 mol·L-1 guanidine nitrate up to 95% completion, the average value of 10 determinations was 0.100 2 mol·L-1 with a relative standard deviation of 0.24%. When the titration was carried out up to only 90%～95% completion, the relative standard deviation was less than 0.3%. This simple and rapid method has been applied to determine guanidine nitrate in a technical _ grade product. The whole titration can be finished within a few minutes. The results agree quite well with the traditional gravimetric results.