Platinum speciation

Lustig, S., Michalke, B., Beck, W. and Schramel, R (1998) Platinum speciation with hyphenated techniques high performance liquid chromatography and capillary electrophoresis on-line coupled to an inductively coupled plasma mass spectrometer -application to aqueous extracts from a platinum treated soil. Fresenius J. Anal. Chem., 360,18-23. 

Platinum speciation using IPC-ICP-MS has been achieved by Zhao et al. [50], An ODS C18 column and 1-heptanesulfonate ion-pairing reagent at pH 2.6 were used to separate the metabolites of cisplatin and cisplatin hydrolysis products. The low pH was required in order to retain thiol containing complexes. All complexes were resolved and urine and blood samples were analyzed by the speciation method. 

R535 B. N. Shelimov, J.-F. Lambert, M. Che and B. Didillon, Molecular-Level Studies of Transition Metal - Support Interactions During the First Steps of Catalysts Preparation Platinum Speciation in the Hexa-chloroplatinate/Alumina System , /. Mol. Catal. A Chem., 2000,158,91... 

Table 12.4 Summary of HPLC-ICP-MS procedures for platinum speciation in analyses of clinical and/or toxicological relevance... 

In a recent study on metal compounds, including the platinum group elements titanium and arsenic, the immunotoxicity was suggested to be dependent on speciation of the metals [90]. 

Best and coauthors utilized IR spec-troelectrochemistry to study the electrochemical reduction of 1902 " " in aqueous solutions with KNO3 as supporting electrolyte [60]. The pH of the solutions was set with appropriate quantities of HNO3 and KOH. The optimal pH range for the study was 2.8-3.4, since within this range speciation of U(VI) is limited to U02 + and (U02)2(0H)2 " ", disproportionation of the electrogenerated U(V) species is minimized, and the U—O stretches for U(VI) are observable in the IR spectrum. The results from the study indicate that initial reduction of at a platinum elec-... 

Sophisticated analytical procedures for the speciation of chromium (Prokisch et al., 1995) and platinum (Michalke et al., 1997) in the soil solution or soil extracts have also been described. 

Speciation and distribution of Group 8,9 and 10 elements (platinum group elements)... 

Capillary electrophoresis (CE) provides high resolution for separation of chemical compounds. Separations of metal ions, of metal ions in different oxidation states and of organometallic compounds are all possible with appropriate CE conditions. This technique is being investigated for speciation. Since sample volumes in CE are generally very small, a detector capable of very low detection limits is desirable. Thus, ICP-MS has been combined with CE to provide a means for studying metal speciation. CE-ICP-MS procedures have been described for the separations of platinum species (Michalke and Schramel, 1996), selenium species (Kumar et al., 1995 Michalke and Schramel, 1996) and arsenic species (Magnuson et al., 1997). Detection limits were about 1 mgl 1 (platinum species) and 10 and 24 pg for Sclv and Scvl, respectively. An application of CE-ICP-MS to platinum species in soils is described in Section 15.8.6. 

Platinum-based compounds are commonly used as cancer treatment agents. Pharmacokinetic studies of these antitumor drugs require ultratrace analysis. Electrothermal vaporization ICP-MS provides low detection limits for small samples [256]. High-performance liquid chromatography with ICP-MS detection allows speciation of platinum compounds in tissues [256]. LA-ICP-MS can be used to study the distribution of platinum in tissues and tumors [256]. Natural levels of Pt are below typical quadrupole ICP-MS detection limits [257]. 

A direct injection nebulizer has been used for CE-ICP-MS [101] with the capillary actually inserted through the central sample introduction capillary of the DEN (Fig. 10.17). This nebulizer is very well suited to the very low flow rates associated with CE and also offers approximately 100% sample transport efficiency. A platinum grounding electrode was used, situated in a three-port connector, which also accommodated the DEN capillary and a makeup buffer flow. The makeup buffer was used so that the DIN operation was independent of the EOF, and the two flows were combined at the capillary exit. The system was used for feasibility studies for As and Se speciation. 

S. Rauch, G. M. Morrison, M. Motelica Heino, O. Donard, Evaluation of speciation, transport and ecological risk of palladium, platinum and rhodium in urban stormwater systems. Proceedings of the 8th International Conference on Urban Storm Drainage, the Institution of Engineers, Australia, 1999. 

D. Klueppel, N. Jakubowski, J. Messerschmidt, D. Stuewer, D. Klockow, Speciation of platinum metabohtes in plants by size-exclusion chromatography and inductively coupled plasma mass spectrometry, J. Anal. Atom. Spectrom., 13 (1998), 255 D 262. 

Goldberg has presented impressive information (given that seawater concentrations are as low as 1.5 pg for Ir and 2 pg for Ru) on the speciation, including redox state, of platinum group metals as a means of interpreting distributions in seawater and marine sediments. Pt and Pd are stabilised in seawater as tetrachloro-divalent anions. Their... 

After intravenous or oral administration of the drug, it undergoes several biotransformations that activate its toxicity (tumor cells as well as nephro- and neurotoxicity). A number of speciation studies that focused on characterization and quantification of parent drug and its possible metabohtes in vitro and in vivo have been reported. Element-specific ICP-MS detection has been applied after LC separation of platinum compounds. In Figure 6, the LC-ICP-MS chromatogram is presented, and this was obtained for the mixture of cancerostatic platinum compounds. ... 

Barefoot, R.R. Distribution and speciation of platinum group elements in environmental matrices. Trends Anal. Chem. 18, 702-707 (1999)... 

Bettmer, J., Buscher, W., Cammann, K. Speciation of mercury, platinum and tin - focus of research and future developments. Fresenius. J. Anal. Chem. 354, 521-528 (1996)... 

Barefoot, R.R. Speciation of platinum compounds a review of recent applications in studies of platinum anticancer drugs. J. Chromatogr. B 751, 205-211 (2001)... 

Timerbaev, A.R., Kiing, A., Keppler, B.K. Capillary electrophoresis of platinum-group elements. Analytical, speciation and biochemical studies. J. Chromatogr. A 945, 25-44... 

Hann, S., Stefanka, Z., Lenz, K., Stingeder, G. Novel separation method for highly sensitive speciation of cancerostatic platinum compounds by HPLC-ICP-MS. Anal. Bioanal. Chem. 

Weber, G., Jakubowski, N., Stuewer, D. Speciation of platinum in plant material. A combination of chromatography, elemental mass spectrometry and electrochemistry. In Zereini, F., Alt, F. (eds.) Anthropogenic platinum-group element emissions. Their impact on men and environment, pp. 183-190. Springer, Berlin (2000)... 

In this chapter, the toxicologically and clinically relevant applications of liquid chromatography (LC) with inductively coupled plasma mass spectrometric (ICP-MS) detection are reviewed (a list of abbreviations used is given at the end of this chapter). After brief characterization of the analytical system, the speciation of arsenic, iodine, mercury, selenium and platinum is discussed. 

Within the context of toxicological and clinical importance, speciation studies have been focused on relatively few elements, mainly aluminum, antimony, arsenic, chromium, iodine, lead, mercury, platinum, selenium and tin. However, coupled HPLC-ICP-MS has most often been used for speciation of arsenic, selenium, iodine and, to a lesser extent, mercury. The primary species of these elements include different oxidation states, alkylated metal and/or metalloid compounds, selenoamino acids and selenopeptides.In addition, applications in smdies on the pharmacokinetics of metal-based drugs (mainly platinum complexes) and metalloproteins should be included. " In the following sections, the advances in speciation smdies of individual elements are reviewed. 

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