Margolis S A, Levenson M
National Institute of Standards and Technology, Analytical Chemistry Division, Gaithersburg, MD 20899-8392, USA.
Fresenius J Anal Chem. 2000 May;367(1):1-7. doi: 10.1007/s002160051589.
The calibration of Karl Fischer instruments and reagents and the compensation for instrumental bias are essential to the accurate measurement of trace levels of water in organic and inorganic chemicals. A stable, nonhygroscopic standard, Water Saturated Octanol, which is compatible with the Karl Fischer reagents, has been prepared. This material, Standard Reference Material (SRM) 2890, is homogeneous and is certified to contain 39.24 +/- 0.85 mg water/mL (expanded uncertainty) of solution (47.3 +/- 1.0 mg water/g solution, expanded uncertainty) at 21.5 degrees C. The solubility of water in -octanol has been shown to be nearly constant between 10 degrees C and 30 degrees C (i.e., within 1% of the value at 21.5 degrees C). The results of an interlaboratory comparison exercise illustrate the utility of SRM 2890 in assessing the accuracy and bias of Karl Fischer instruments and measurements.
卡尔费休仪器和试剂的校准以及仪器偏差的补偿对于准确测量有机和无机化学品中的痕量水分至关重要。现已制备出一种稳定、不吸湿且与卡尔费休试剂兼容的标准物质——水饱和辛醇。这种物质，即标准参考物质（SRM）2890，具有均匀性，经认证在21.5摄氏度时溶液中含有39.24 +/- 0.85毫克水/毫升（扩展不确定度）（47.3 +/- 1.0毫克水/克溶液，扩展不确定度）。已表明水在辛醇中的溶解度在10摄氏度至30摄氏度之间几乎恒定（即在21.5摄氏度时的值的1%以内）。实验室间比对实验的结果说明了SRM 2890在评估卡尔费休仪器和测量的准确性及偏差方面的实用性。
