Synergistic extraction of Zn2+ using butanol from various chloride ion concentrations into 1- phenyl -3- methyl -4- trichloro acetyl pyrazolone -5 (HTcP) in benzene and hexane showed above 80% extraction yield. This was in contrast to 0% extraction of Zn2+ in the absence of butanol as a synergist throughout the pH range 0 - 7 studied. The data presented showed that extraction increases as chloride ion concentration increases from 0.1M to 1M. Also, overall optimal extraction is higher for extraction using (HTcP) in benzene than hexane while extraction of Zn2+ at lower pH value is more effective in hexane solution rather than benzene. Thus the presence of Cl- in buffer solution shows a salting out effect as the concentration in the buffer medium increases. Slope analysis showed that the extracted adduct complex specie had the formula Zn(TcP)2.2BuOH. The pH1/2, log Kex, log KD, the extraction mechanism and extracted species, for all the systems are presented. The relevant patents are discussed.
Keywords: Synergistic extraction, chloride ion, buffer medium, slope analysis