A robust method for speciation, separation and photometric characterization of all [PtCl6-nBrn](2-.) (n=0-6) and [PtCl4nBrn](2-) (n=0-4) complex anions by means of ion-pairing RP-HPLC coupled to ICP-MS/OES, validated by high resolution Pt-195 NMR spectroscopy

作者：van Wyk Pieter Hugo; Gerber Wilhelmus J; Koch Klaus R^*

来源：Analytica Chimica Acta, 2011, 704(1-2): 154-161.

DOI：10.1016/j.aca.2011.07.037

• Speciation of [PtCl6-nBrn](2-) (n=0-6) and [PtCl4-nBrn](2-) (n=0-4) complex anions
• Ion-pair Reversed Phase-HPLC coupled
• Inductively Coupled Plasma-Mass
• Spectrometry/Optical Emission
• Spectroscopy
• Pt-195 Nuclear Magnetic Resonance molar absorptivities of [PtCl6-nBrn](2-) (n=0-6) and [PtCl6-nBrn](2-) (n=0-4) complexes

A robust reversed phase ion-pairing RP-HPLC method has been developed for the unambiguous speciation and quantification of all possible homoleptic and heteroleptic octahedral platinum(IV) [PtCl6_n,Br-n 12(n = 0-6) as well as the corresponding platinum(II) [PtCl4_Br-n(n)](2-) (n = 0-4) complex anions using UV/Vis detection. High resolution Pt-195 NMR in more concentrated solutions of these Pt-II/IV complexes (>= 50 mM) served to validate the chromatographic peak assignments, particularly in the case of the possible stereoisomers of POII/IV complex anions. By means of IP-RP-HPLC coupled to ICP-MS or ICP-OES it is possible to accurately determine the relative concentrations of all possible Pt-II/IV species in these solutions, which allows for the accurate determination of the photometric characteristics (lambda(max) and epsilon) of all the species in this series, by recording of the UV/Vis absorption spectra of all eluted species, using photo-diode array, and quantification with ICP-MS or ICP-OES. With this method it is readily possible to separate and estimate the concentrations of the various stereoisomers which are present in these solutions at sub-millimolar concentrations, such as cis- and trans-[PtCl4Br2](2-),fac- and mer[PtCl3Br3](2-) and cis- and trans-[PtCl2Br4](2-) for Pt-IV, and cis- and trans-[PtCl2Br2](2-) in the case of Pt-II. All mixed halide Pt-II and Pt-IV species can be separated and quantified in a single IP-RP-HPLC experiment, using the newly obtained photometric molar absorptivities. epsilon, determined herein at given wavelengths.

• 出版日期2011-10-17