Development of selective pre-concentration methodology of some of the platinum-group metals in acidic solutions, followed by their direct determination by ICP-OES

Abstract

The trace analysis of the platinum-group metals in complex, severely interfering matrices, such as industrial effluent, has been the focus of much research in_the past forty years. However, despite the greater availability of much improved instrumentation, such as ICP-OES, NAA and XRF, most analytical techniques currently employed for the determination of the platinum-group metals require selective sample preparation that ensures enrichment of the individual platinum-group metals at the trace and ultra trace level, along with simultaneous matrix removal, prior to determination. N-benzoyl-N', N'-dialkylthioureas act as selective complexing agents for the enrichment of platinum-group metals from strongly interfering matrices. This study describes the development of selective pre-concentration methodology for some of the platinum-group metals in post- processing effiuents (using this class of ligands) followed by their direct determination by ICP- OES, in an effort to recover the residual platinum-group metals present in real waste effiuents that are currently unable to be recovered, representing a substantial loss of income to the South African platinum-group metal producers.