Abramović B F, Gaál F F, Cvetković S D
Institute of Chemistry, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, Yugoslavia.
Talanta. 1992 May;39(5):511-5. doi: 10.1016/0039-9140(92)80173-b.
Two titrimetric methods were developed for the determination of fluoride contents in some pharmaceutical preparations used for fluoridation. One of the methods is catalytic controlled-current potentiometry involving two identical platinum indicator electrodes and thorium nitrate as titrant. The reaction between hydrogen peroxide and potassium iodide in the presence of acetate buffer (pH 3.6), which is catalysed by the excess of thorium nitrate, served for the end-point indication. The other method is the automatic potentiometric titration involving a fluoride-selective electrode and lanthanum nitrate as titrating agent. In both procedures, special attention was paid to sample pretreatment and to determination of optimal experimental conditions. Fluoride contents in the range 16-32 microg/ml are determined with a relative standard deviation less than 1.34%. The results are compared to those obtained by standard methods described in the United States Pharmacopeia XXI and recommended by the manufacturer of the preparations.
开发了两种滴定法用于测定一些用于氟化的药物制剂中的氟含量。其中一种方法是催化控制电流电位法，涉及两个相同的铂指示电极和硝酸钍作为滴定剂。在过量硝酸钍催化下，过氧化氢与碘化钾在乙酸盐缓冲液（pH 3.6）存在下的反应用于终点指示。另一种方法是自动电位滴定法，涉及氟离子选择电极和硝酸镧作为滴定剂。在这两种方法中，都特别注意了样品预处理和最佳实验条件的确定。氟含量在16 - 32微克/毫升范围内测定时，相对标准偏差小于1.34%。将结果与美国药典XXI中描述的标准方法以及制剂制造商推荐的方法所获得的结果进行了比较。
