氢氧化钠-尿素法测定烟草木质素预处理方法的优化

摘要

[目的]优化氢氧化钠-尿素法(NU法)测定烟草木质素含量的预处理方法.[方法]分别用中性洗涤剂和氢氧化钠-尿素溶液对烟梗、烟叶碎片(烟片)、烟叶碎末(烟末)进行预处理,分析比较了2种溶液对干扰物的去除效果,并对2种预处理方法下NU法的测定结果进行了对比评价.[结果]中性洗涤剂对烟梗、烟片、烟末的干扰物去除率近80％,比氢氧化钠-尿素溶液提高13％～ 16％;在中性洗涤预处理方法下,NU法测得3种烟草样品的木质素含量大小关系为烟梗＞烟片＞烟末,与氢氧化钠-尿素预处理下的测定结果恰恰相反;预处理方法优化后NU法的精密度为2.03％,满足检测需求.[结论]研究可为烟草木质素含量测定的预处理方法优化提供参考.%[Objective] To optimize the pretreatment method of NaOH/Urea method used for content determination of lignin in tobacco.[Method] Tobacco stems,scraps and dusts were pretreated with neutral detergent and NaOH/Urea solution respectively,then both the interfering substances removal rates and the content results determined by NaOH/Urea method under each pretreatment method were compared.[Result] The results showed that:Neutral detergent could remove interfering substances in tobacco stems,scraps and dusts by about 80％,which is 13％-16％ higher than that of NaOH/Urea solution;The order of lignin content determined by NaOH/Urea method under neutral detergent pretreatment was tobacco stems ＞ scraps ＞ dusts,which was right opposite from that under NaOH/Urea pretreatment;the precision of NaOH/Urea method after pretreatment optimization reached 2.03％,which had already met the determination demand.[Conclusion] The study can provide reference for pretreatment optimization for content determination of lignin in tobacco.