Determination of Fluorine in Fluoro-Organic Compounds
Abstract
An analytical procedure is described for the determination of fluorine in fluoro-organic compounds based on (1) decomposition of the sample by refluxing with sodium in 1-hexanol, and (2) titration of fluoride ion with thorium nitrate using sodium alizarin sulfonate as indicator. The analysis requires about thirty minutes. Four fluoro-organic compounds were analyzed. Fluorine in sodium fluoroacetate was about 3% above the calculated quantity; values for methyl fluoroacetate were about 4% low. The average value for di-isopropylfluorophosphate was approximately 1% below the theoretical, while in beta-fluoroethanol the fluorine values averaged about 11% low. In all analyses the average deviation from the mean was about + or - 2%. Purified di-isopropylfluorophosphate in a 45% ethanol solution contained 0.15% fluoride ion, but no fluoride ion was found in either methyl fluoroacetate or beta-fluoroethanol. Samples from two lots of sodium fluoroacetate contained 8.5% sodium fluoride. In the hope of enhancing the color change at the end-point in the thorium nitrate titration, fifty-four dyestuffs in mixtures with sodium alizarin sulfonate were tested. Only one appears to be of value. A comparison of Solochrome Brilliant Blue BS with sodium alizarin sulfonate showed each indicator to have some advantage, depending on the concentration range of fluorine; the former is more sensitive at lower contractions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 14, 1944
- Accession Number
- ADB811142
Entities
People
- James Coles
- Jason M. Salsbury
- John H. Yoe
Organizations
- University of Virginia