Diphenic acid as an analytical reagent

Summary Diphenic acid behaves as a selective reagent for the estimation of thorium in presence of phosphate, arsenate, molybdate, alkaline, earths, copper, cadmium, lead, bismuth, tin, aluminium, chromium, nickel, cobalt, zinc, manganese, magnesium and palladium. Thorium can be successfully separated from the cerite earths by the reagent from solutions having thoria: earth oxide ratio 126 by single precipitation and by double precipitation when the above ratio is 144. The reagent can separate thorium from solutions having ThO₂U₃O₈ ratio upto 180 by double precipitation. The metal can also be recovered from monazite sands.Thanks are expressed hereby to Dr. A. K. Ghosal, Principal, Darjeeling Government College and Dr. A. K. Mukherjee of Indian Association for the Cultivation of Science, Calcutta, for their kind encouragement and to the Government of India, Ministry of Natural Resources and Scientific Research for a gift of Indian Monazite for analysis.