通过定量核磁共振精确确定有机溶液中的微量水
Kangni Wan1,2,3, Ming Li1, Ting Huang1
1Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing 100029, People's Republic of China.
Analytical chemistry
|October 16, 2023
概括
一种新的定量核磁共振 (qNMR) 方法可以准确地确定微量水含量. 这种qNMR方法为卡尔·菲舍尔定位提供了一个稳定,敏感的替代方案,需要更小的样本大小,克服不溶性物质的局限性.
科学领域:
- 分析化学 分析化学
- 频谱学是一种光谱学.
- 核磁共振是一种核磁共振.
背景情况:
- 精确确定微量水在各种科学和工业应用中至关重要.
- 现有的方法,如Coulometric Karl Fischer (CKF) 定位,具有局限性,特别是在甲醇不溶性物质和样本大小要求方面.
研究的目的:
- 开发和验证一种新的定量1H核磁共振 (qNMR) 方法,用于精确的微量水的确定.
- 通过使用qNMR建立一个导出方程来精确量化含水量.
- 为了证明qNMR方法与传统技术相比的适用性和优势.
主要方法:
- 使用了定量1H核磁共振 (qNMR) 光谱学.
- 根据质子信号来计算含水量的特定方程.
- 使用可追溯到Coulometric Karl Fischer (CKF) 定位的水标准验证了qNMR方法.
- 高场NMR (HF-NMR) 和低场NMR (LF-NMR) 用于分析各种样品.
主要成果:
- 在qNMR方法和已建立的CKF水标准定位之间观察到很好的一致性.
- 在不同的水含量水平 (10.02,1.006和0.103 mg/g) 中,qNMR方法表现出高准确度和精度.
- 量化的极限低至6.7μg,与CKF定位相比,样本大小要求要小得多.
- 该方法有效地消除了环境湿度和溶剂背景水的影响.
结论:
- 开发的qNMR方法为微量水的确定提供了准确,稳定和敏感的方法.
- 这种qNMR技术克服了CKF方法的关键局限性,包括适用于甲醇不溶性物质和减少样本体积的需求.
- 该方法通过NMR内部标准提供直接可追溯到SI单位,提高了其对各种分析挑战的可靠性.
相关概念视频
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