DOE Chemical IndustryApplication
The bottom line:
Experimenters learned how to correct an Aluminum analysis for fluoride interference. The accurate concentration of aluminum in water and wastewater by the Eriochrome Cyanine R method is now possible.
Fluoride interferred with the standard method for analyzing aluminum in water and wastewater. The magnitude of this effect was not known.
Experimenters used an I-Optimal design with aluminum levels from 0 to 0.5 mg/L and fluoride levels from 0 to 1.75 mg/L . The concentration of aluminum in the water was measured by the Eriochrome Cyanine R technique.
The experimenters showed that the strong interaction between aluminum and fluoride was more important than the presence of fluoride itself. This information allowed them to correct for the interference.