Certification of the reference material of water content in water saturated 1-octanol by Karl Fischer coulometry, Karl Fischer volumetry and quantitative nuclear magnetic resonance
- 作者：Haifeng Wang ; wanghf@nim.ac.cn ; Kang Ma ; Wei Zhang ; Jia Li ; Guohua Sun ; Hongmei Li
- 关键词：Karl Fischer titration ; Quantitative nuclear magnetic resonance ; Water content ; Certified reference material
- 刊名：Food Chemistry
- 出版年：2012
- 期刊代码：48_03088146
- 类别：abs
- 出版时间：15 October, 2012
- 卷：134
- 期：4
- 页码：2362-2366
- 文件大小：251 K
摘要
Certified reference materials (CRMs) of water content are widely used in the calibration and validation of Karl Fischer coulometry and volumetry. In this study, the water content of the water saturated 1-octanol (WSO) CRM was certified by Karl Fischer coulometry, volumetry and quantitative nuclear magnetic resonance (Q NMR). The water content recovery by coulometry was 99.76%with a diaphragm-less electrode and Coulomat AG anolyte. The relative bias between the coulometry and volumetry results was 0.06%. In Q NMR, the water content of WSO is traceable to the International System (SI) of units through the purity of internal standard. The relative bias of water content in WSO between Q NMR and volumetry was 0.50%. The consistency of results for these three independent methods improves the accuracy of the certification of the RM. The certified water content of the WSO CRM was 4.76%with an expanded uncertainty of 0.09%.