Fluoride by Direct Measure
Method Abstract #31
Scope and Application
This method conforms to Standard Methods 4500-F_ C, ASTM D 1179 (B) and ISO 10359-1. It determines the concentration of fluoride ions in a water sample.
Method and Summary
The concentration of fluoride is determined by a fluoride ion selective electrode. After calibrating with known standards, the sample’s response can be compared to the calibration curve and a concentration determined. Both the standards and the samples are pre-treated with TISAB (Total Ionic Strength Adjuster) to ensure that the background response from each sample is similar.
Sample Calibration
Method Performance
*Data for this measuring range was obtained using laboratory prepared standards formulated from sodium fluoride. The measuring range may be increased by using auto-dilution.
**The Method Detection Limit (MDL) was determined based on data obtaining a coefficient of variance better than 30%. Results may differ depending on laboratory practices and sample matrix.
RSD values are better than those specified in Standard Methods.
