Determination of Lithium in Organic Matrix Using Coated Wire Lithium Ion Selective Electrode

Coated wire lithium ion selective electrode was fabricated using lithium ionophore-VI, 2-nitrophenyl octyl ether (NPOE) and potassium tetrakis(p-chlorophenyl)borate (KTpClPB) on platinum wire. Lithium ion selective electrode was giving Nernstian response from 10 -1 M to 10 -4 M with a detection limit of 3x10 -5 M. The calibration slope of this lithium ion selective electrode was found to be 58.5 ± 1.0 mV/decade. The selectivity coefficients of this electrode with respect to the different ions were determined by matched potential method. This lithium ion selective electrode was then used for the determination of lithium in complex chemical matrix containing hexamethylene tetramine, formaldehyde, urea and ammonium nitrate etc. which are the wash streams generated during the sol-gel process employed for preparation of Li2TiO3 microspheres.