Speciation of platinum by GFAAS using various possibilities of analytical signal enhancement.

A novel method for determination of platinum species by application of graphite furnace atomic absorption spectrometry (GFAAS) was developed. The principle of determination is the formation of platinum ion associates (IA) with SCN and polymethine basic agent 1,3,3-trimethyl-2-[3-(1,3,3-trimethyl-1,3-dihydroindol-2-yliden)-propyl-1,3-dienyl]-3H-indolium chloride (TTDI), which can then be extracted by various organic solvents. Different options for analytical signal intensification (ultrasonic and microwave energy) were examined. The conditions found for ion associate formation and extraction have enabled the proposing of a new Pt(II) and Pt(IV) speciation process. These species can be reliably determined simultaneously at concentration ratios from 1:5 to 5:1. Moreover, the ion associates of platinum with TTDI can be extracted with toluene up to a volume ratio of aqueous and organic phases of V:V = 50:1. This fact for Pt determination using GFAAS means decreasing the limit of detection (LOD) from 7.1µgL to 0.3µgL. The method was applied for Pt determination in a model and in spiked water samples.