Determination of Oxide in Fluoride Salts Using an Yttria-Stabilized-Zirconia Oxygen Pump

An improved method over a previous technique has been developed to determine the ppm oxide concentration of fluoride salts. The oxide is released as oxygen gas by the reaction of the test salt with potassium bromotetrafluoride at 450 °C. The molecular oxygen released is then passed through a zirconia oxygen pump which selectively removes the oxygen. The current response is recorded as a chronoamperogram, from which the ppm oxide content of the salt can be obtained. Oxygen recovery from an yttrium oxide standard was better than 99%. The precision of analysis of FLINAK was better than 13% for samples containing 110-170 ppm oxide. The LOD was 12 μg of oxygen, and the analytical range was 120 ppm to >20% for a 0.1-g sample.