Determining Flouride with Oxygen Bomb Ashing and Ion Selective Electrode
Zhi Su (Life and Environment Science Institute of Xinjiang Normal University ,Urmuqi830054)
The paper introduces a method for determining the fluoride of food, such as rice, soybean and wheat flour etc. with oxygen bomb and F-ion selective electrode. Firstly ,the sample was burned in the oxygen bomb with high pressure and purity oxygen, then absorbing the ash with alkali solution and using the TISAB for eliminating interference of Al3+、Fe3+. F-ion selective electrode was used for determining the content of fluoride in organic substance under the ranges of PH 5￣8. when the fluoride concentration at the ranges of 1￣10-6mol.L-1, the percent recovery is 96.4%￣102.5%.