摘要
采用核磁共振氢谱(1H NMR)、选择性一维全相关谱(1D-TOCSY)及定量核磁共振法(qNMR)对液态乳中的1,2-丙二醇进行了快速筛查及含量测定,并与气相色谱法的测定结果进行了比较。1H NMR法以液态乳基质中1,2-丙二醇的甲基质子信号特征为初步定性标准,选择性一维全相关谱法以1,2-丙二醇的亚甲基和次甲基质子信号特征为精确定性标准。在定性检测基础上,采用定量核磁共振法以1,2-丙二醇δ1.15处的质子峰为定量峰,3-(三甲基硅基)氘代丙酸钠(TMSP)δ0.00处的峰为内标峰,测定了液体乳中1,2-丙二醇的绝对含量。方法的检出限为0.002 mg/mL,定量下限为0.006 mg/mL。实际样品测定结果显示,NMR法与气相色谱法的检测结果一致,且NMR法前处理简单,操作方便,专属性高,在提高检测效率的同时能够避免假阳性结果出现,非常适合实际检测中液体乳中1,2-丙二醇的批量、快速检测。
A proton nuclear magnetic resonance(1H NMR)combined with 1D total correlation spectroscopy(1D-TOCSY)and quantitative nuclear magnetic resonance spectroscopy(qNMR)was developed for detection and quantitation of 1,2-propanediol in liquid milk.The proton signals of methyl of 1,2-propanediol(1H NMR)and the methylene and methyne of this molecule(1D-TOCSY)were used for rapid screening and precise detection of 1,2-propanediol in liquid milk,respectively.Meanwhile,the content of 1,2-propanediol in liquid milk was detected by the qNMR method,with the signal of 1,2-propanediol atδ1.15 as quantitative peak and 2,2,3,3-D4-3-(trimethylsilyl)propionic acid sodium salt(TMSP)atδ0.00 as internal standard peak.The detection limit and quantitation limit of the method were 0.002 mg/mL and 0.006 mg/mL,respectively.Comparison of this NMR and gas chromatography method revealed that they were equal within experimental error.Furthermore,the NMR method was simple in operation and had the high specificity,which not only improved the detection efficiency,but also avoided false positive results.It was suitable for batch and rapid detection of 1,2-propanediol in liquid milk.
作者
李玮
耿健强
许华
林立
LI Wei;GENG Jian-qiang;XU Hua;LIN Li(Beijing Municipal Center for Food Safety Monitoring and Risk Assessment,Beijing 100094,China)
出处
《分析测试学报》
CAS
CSCD
北大核心
2020年第9期1131-1136,共6页
Journal of Instrumental Analysis
基金
北京市优秀人才培养资助项目(2018000027174G302)
国家市场监督管理总局技术保障专项项目(2019YJ003)。
关键词
核磁共振氢谱法
选择性一维全相关谱
定量核磁共振法
液体乳
1
2-丙二醇
proton nuclear magnetic resonance(1H NMR)
1D total correlation spectroscopy(1D-TOCSY)
quantitative nuclear magnetic resonance spectroscopy(qNMR)
liquid milk
1,2-propanediol
