Simultaneous thermogravimetric determination of potassium, rubidium and caesium as their tetra-phenylborates and tetra(p-fluorophenyl)borates

Abstract

A thermogravimetry for simultaneous determination of K, Rb and Cs has been studied with their tetraphenylborates (M[TPB]) and tetra(p-fluorophenyl) borates (M[F4TPB]). These three metal ions were completely recovered from a solution as M[TPB], whereas only Cs quantitatively as M[F4TPB] which contained a small amount of Rb[F4TPB]. About 10 mg of each precipitate was heated at a rate of 5.6°C min-1 in an air stream of 50 cm3 min-1. The amounts of K, Rb and Cs were determined by the equations. Experimental error was within 10% when the amount of each metal in 50 cm3 of sample solution was more than 5 mg. © 1990, The Japan Society for Analytical Chemistry. All rights reserved.