顶空-卡尔费休库仑法测定烟用纸张中水分

Determination of the Moisture Content in Cigarette Paper by Headspace-Karl Fischer Coulometric Method

关键词:  烟用纸张  水分  卡尔费休库仑法  干燥炉

Key Words:cigarette paper  moisture  karl fischer coulometry method  drying furnace

摘要:本研究建立了顶空-卡尔费休库仑法测定烟用纸张中水分含量的方法，通过优化加热温度、滴定时间、样品形态和样品量等实验条件，以实现烟用纸张中水分含量的快速测定。结果表明，测定烟用纸张水分的最佳条件为：干燥炉温度120 ℃，延迟时间终止模式，滴定时间10 min，试样质量0.06 g。在不同浓度水平下，该方法的回收率为92.20%~103.61%，相对标准偏差为1.12%~4.86%。与烘箱法、卤素法和气相色谱热导检测（GC-TCD）法相比，测定结果接近，符合GB/T 462—2008的相关要求。顶空-卡尔费休库仑法对于水分的萃取更加充分，更能真实反应样品中水分含量。顶空-卡尔费休库仑法简单快速、准确可靠，适用于批量分析烟用纸张中的水分含量。

Abstract:In this study， a headspace-Karl Fischer coulometric method was established to determine the moisture content in cigarette paper. By optimizing the experimental conditions such as heating temperature， titration time， sample shape and sample size， the moisture content in cigarette paper was quickly determined. The results showed that the optimum conditions for detecting the moisture content of cigarette paper were as follows： drying furnace temperature was 120 ℃， adopting delay time termination mode， titration time was 10 min， sample mass was 0.06 g. The recoveries of the method were 95.46%~104.99% and the relative standard deviations were 1.12%~4.07% at different spiked levels. Compared with oven method， halogen method and thermal conductivity detection by gas chromatography （GC-TCD） method， the determination results were close， and met the relevant requirements of GB/T 462—2008. The Headspace-Karl Fischer coulometric method could extract water more fully， and truly reflect the moisture content in the sample. Headspace-Karl Fischer coulometric method is simple， rapid， accurate and reliable， and suitable for batch analysis of moisture content in cigarette paper.