烟草中中性洗涤纤维和酸性洗涤纤维测定方法的优化

Optimization of the Method for Determination of NDF and ADF in Tobacco with Detergent Method

为了减少高毒试剂苯的使用,缩短脱脂时间,减少酸性洗涤过程中半纤维素水解不完全对测定结果的干扰,采用乙醇–乙醚混合液超声对烟草样品进行脱脂处理,用2 mol/L盐酸洗涤后测定酸性洗涤纤维,对YC/T347–2010标准方法进行优化。方法优化后减少了试剂毒害,脱脂时间由8.5 h缩短为1.5 h;测定酸性洗涤纤维中半纤维素水解更完全,洗涤剂法计算的半纤维素含量与水解法测定半纤维素含量的结果基本一致。改进后方法的回收率为98.38%~99.97%,测定结果的相对标准偏差为0.25%~1.88%(n=6)。该方法可以代替苯–醇–醚加热回流脱脂法测定烟草及烟草制品中中性洗涤纤维和酸性洗涤纤维。

In order to reduce the dosage of high toxic reagent of benzene,shorten the time of the degreasing process,and reduce the interference of incomplete hydrolysis of hemicellulose in washing process with acid detergent method,ethanol-ether mixture solvent was used for sample pretreatment after ultrasonic degreasing,and2mol/L HCl was used to wash the sample,then the acid detergent fiber was determined.Compared with general method,the optimization method had advantages of reducing the reagent toxicity,shortening the time from8.5h to1.5h,using2mol/L HCl to determinate the acid detergent fiber,which make hydrolysis more complete.Detergent method was used to calculate the hemicelluloses content,the results were consistent with those of hydrolysis method.The recoveries were98.38%-99.97%,and the relative standard deviations of detection results were0.25%-1.88%(n=6).The method is suitable for the determination of neutral detergent fiber and acid detergent fiber in tobacco and tobacco products instead of the mixture-solvent(containing benene,ethanol and ether)heating reflux method.