木质素中氯离子的测定方法探讨

The discussion of determination methods for chlorine ion of lignin

木质素含有过高浓度的氯离子会对牲畜、土壤、植物生长造成严重而持久的危害,并危害人体健康。采用摩尔法、佛尔哈德返滴定法和电位滴定法测定木质素中的氯离子,并分别利用F检验和t检验进行分析。结果表明,3种测定方法的精密度无显著性差异,加标回收率在98%～101%,准确度较好;摩尔法的平均值与佛尔哈德返滴定法或电位滴定法的平均值存在显著性差异,佛尔哈德返滴定法与电位滴定法的平均值之间无显著性差异;但是相比较而言,电位滴定法的准确度和精密度最好,佛尔哈德返滴定法次之。建议采用电位滴定法对木质素中的氯离子进行检测。

High concentration of chloride ions in lignin could cause severe and enduring harm for the live- stock, soil, plant growth, and even harm human health. Chloride ions in lignin were determined by using molar method, Volhard back titration and potentiometric titration method, using F test and t test analysis. The results showed that the measuring precision of three methods had no significant difference, the accura- cy was better when the addition standard recovery was in the range of 98% ～101% ;the average value had significant effect between molar method and the other two methods, and had no significant difference between Volhard back titration and,potentiometric titration method ;but comparatively speaking,the accu- racy and precision of potentiometric titration were best,followed by Volhard back titration. It was sugges- ted that chloride ions in lignin were detected by potentiometric titration.