壬基酚中微量铁含量测定方法的改进

An Improved Method for the Determination of Trace Iron in Nonyl Phenol

对用于有机产品中微量铁含量测定的邻菲罗啉法中的样品处理方法进行了改进，在适量浓硫酸存在下加热，使壬基酚碳化后再蒸干灼烧。此改进方法具有良好的重复性和可靠性。

The Ferroin method (by forming tris 1,10 phenanthrolion ferrous ion)is suitable for the determination of iron in many industrial organic row material.It,however,does not suit to determine the trace iron in nonyl phenol.Because the latter is a very greasy and adhesive material which brings great difficulty in sample pretreatment before spectrophotometry.During evaporation of the organic mixture with relative high boiling point, the iron contained is apt to be lost heavily.This makes the results of iron content lower than that it should be.To solve the problem the procedure has been improved by carbonizing the nonyl phenol through adding appropriate amount of concentrated sulfuric acid and heating at a temperature not high than 200 ℃, then by burning at ca. 600 ℃. The improved procedure has been proved to be of good repeatability and reproducibility and suitable for the determination of trace iron in samples of similiar kinds.