Analytical Sciences


Abstract − Analytical Sciences, 26(5), 603 (2010).

Determination of Total Fluoride in Boron-containing Solutions
Siqingaowa BORJIGIN,* Toshiaki YOSHIOKA,* and Tadaaki MIZOGUCHI**
*Graduate School of Environmental Studies, Tohoku University, 6-6-7 Aramaki Aza Aoba, Aoba, Sendai 980-8579, Japan
**Environment Conservation Research Institute, Tohoku University, 6-6-11 Aramaki Aza Aoba, Aoba, Sendai 980-8579, Japan
We describe a pretreatment method before determining the total fluoride in solutions containing tetrafluoroborate ion (BF4) with ion-selective electrodes (ISEs). BF4 was quantitatively converted to free fluoride by reacting with aluminum ions. The total fluoride concentration was then determined by ISE analysis without preliminary steam distillation using a tartrate- and tris(hydroxymethyl)methylamine (TRIS)-based total ionic strength adjustment buffer (TISAB). We investigated the effects of various factors on the decomposition of BF4 with aluminum ions, including the concentration of aluminum, pH, reaction temperature, and reaction time. The quantitative decomposition of BF4 was complete after 2 h at 50°C or 1 h at 70°C.