固态^(13)C CP/MAS NMR光谱测定烟草中果胶含量的分析方法研究  

Development of an analysis method for determination of pectin in tobacco by solid state ^(13)C CP/MAS NMR

作　　者：牛凡超 谢卫 黄朝章 蓝洪桥 黄延俊 高淼 杨俊[1] NIU Fanchao;XIE Wei;HUANG Chaozhang;LAN Hongqiao;HUANG Yanjun;GAO Miao;YANG Jun(Department of Chemistry,University of Science and Technology of China,Hefei 230026,China;Technology Center,China Tobacco Fujian Industrial Co.,Ltd.,Xiamen 361001,China)

机构地区：[1]中国科学技术大学化学系,安徽合肥230026 [2]福建中烟有限责任公司技术中心,福建厦门361001

出　　处：《中国科学技术大学学报》2021年第8期637-646,共10页JUSTC

基　　金：supported by the Science and Technology Project of Fujian China Tobacco Industry Co.,Ltd. (FJZYHZJH2020001)

摘　　要：通过固态^(13)C CP/MAS NMR技术,成功地建立了一种新方法用于烟草果胶的定量分析研究.首先,将二甲基硅橡胶设计成5.5 mm外径的硅胶管用作强度参考,再装填到5.5 mm内径的二氧化锆转子内以制成NMR样品管.然后,对样品管中的果胶样品进行检测以获得相应的^(13)C CP/MAS NMR光谱,再利用波谱去卷积技术分别对171 ppm处的C-6峰进行处理,以此消除重叠峰的干扰.最后,用指定的C-6峰与强度参考峰的面积比为纵坐标,聚半乳糖醛酸(PGA)标准样品的质量为横坐标,以此来建立工作曲线.获得工作曲线方程为I=0.0082m-0.2470,r2=0.9981,检出限和定量限分别为1.81 mg·g^(-1)、6.04 mg·g^(-1).方法的加标回收率在94.33%~102.77%范围内,平均回收率为98.11%,RSD(n=5)小于2.32%.该方法用于测定6种不同烟草样品中的果胶含量,结果发现:与标准方法测量的结果相比,其相对误差在-4.94%~3.84%之间.研究表明,通过固态^(13)C CP/MAS NMR光谱和硅橡胶管建立的新方法准确、快速、简单,适用于烟草及其制品中果胶含量的定量分析.A quantitative analysis method was developed for determination of pectin content in tobacco samples by solid state ^(13)C CP/MAS NMR.A 5.5 mm outer diameter of dimethyl silicone rubber tubing was designed and utilized as a reference of intensity,which was packed into a 5.5 mm inner diameter zirconia NMR rotor to construct an NMR sample tubing.The powder samples filled into the sample tubing were detected to obtain ^(13)C CP/MAS NMR spectra.The peak of C-6 at 171 ppm was processed with spectral deconvolution to eliminate interference from overlapping peaks.The calibration curve was established with the area ratios of assigned C-6 peak to intensity reference peak and the mass of the polygalacturonic acid(PGA).This method was used to determine the pectin content in six different tobacco samples.Relative errors were between-4.94%and 3.84%compared with the results measured by the standard method.The recovery of PGA from spiked tobacco samples was ranged from 94.33%to 102.77%,the RSD(n=5)was less than 2.32%.It demonstrates that the ^(13)C CP/MAS NMR method with a novel intensity reference possesses the properties of speediness,accuracy and simplicity,which is suitable for the quantitative analysis of pectin content in tobacco.

关 键 词：果胶 二甲基硅橡胶管 固态^(13)C CP/MAS NMR 烟草 

分 类 号：O652.1[理学—分析化学]