Determination of lithium by potentiometry using fluoride ion selective electrode

A potentiometric method was developed for the determination of lithium in ethanol medium using ammonium fluoride as titrant and fluoride ion selective electrode for end point detection. The precision of the measurements for samples containing 1 to 3 mg of Li was found to be better than 0.5%. The developed methodology was then employed for the determination of concentration of lithium (Li) in a complex chemical mixture containing hexamethylenetetramine (HMTA), formaldehyde and ammonium nitrate, which are the wash streams generated in the sol–gel process employed for preparation of Li2TiO3 microspheres. The concentration data profile agreed with the isotopic profile obtained by thermal ionization mass spectrometry.