FIA-FAAS system including on-line solid phase extraction for the determination of palladium, platinum and rhodium in alloys and ores

A number of aliphatic mono- and triamines have been investigated as potenti al reagents for solid phase extraction of Rh, Pd and Pt. Platinum group met als are recovered from hydrochloric acid solutions as ionic associates of t heir chloride complexes with protonated amines. The recovery of metals depe nds both on hydrophobic properties of amine and sorbent and on sorption beh aviour of amine itself. For on-line solid phase extraction of platinum grou p metals 4-(n-octyl)diethylenetriamine and hyper cross-linked polystyrene s orbent SSPS have been applied. Quantitative recovery of rhodium and platinu m in the form of their hexachloride complexes was achieved under non-equili brium conditions of on-line dilution. Metals recovered are quantitatively e luted with 1 M hydrochloric acid solution in ethanol. A new FIA-FAAS method for the determination of Rh, Pd and Pt in solutions based on the decomposi tion of ores and alloys has been proposed. The RSD values are 0.03-0.08 at 50-ppb concentration level. The detection limits are 3-8 ppb for 1 min of p reconcentration. The accuracy of the procedure was verified by the analysis of standard reference materials of sulfide ores and alloys. (C) 2000 Elsev ier Science B.V. All rights reserved.