近红外分析的样品前处理新技术研究

样品的水分含量、粒度等因素对近红外的检测结果会产生较大影响.在近红外实验室分析中,为获得较好的分析准确度,一般需采用干燥和粉碎等处理.文章以云南优质烤烟为实验材料,在近红外分析样品的前处理中创新性地采用微波快速干燥技术以及普通家用食物粉碎机快速粉碎的方法,使整个样品前处理时间可控制在5 min以内,同传统烘箱干燥、粉碎过筛等方法相比其处理速度可提高几十倍.实验结果表明:当样品的水分含量差异较大时,通过微波快速干燥方法能有效提高和保证模型分析的准确度;烤烟样品经过普通家用食物粉碎机快速粉碎25 s后可消除粒度差异对近红外检测结果的影响.研究结果可为近红外分析工作者提供一种快速有效的干燥和粉碎技术,从而简化样品的前处理.

New Technology for Sample Preprocessing in NIR Analysis

Sample's moisture content and granularity would have an important influence on NIR veracity.Preprocesssing methods have been used for NIR analysis to achieve better NIR veracity.With Yunnan flue-cured tobacco as study materials,the authors innovatively applied microwave fast drying technology and home pulverizer to tobacco preprocessing,which could finish the preprocessing in 5 min,faster than the traditional methods such as oven drying and sifting.Results showed that:microwave fast drying technology could improve NIR analysis veracity when samples' moisture content had a wide range;influence of samples' granularity on NIR veracity could be eliminated after 25 s home pulverizer shatter.This study can offer a new method for NIR analysis workers to simplify NIR preprocessing.