Tomoshige Morita

Thin-layer chromatographic separation of rhodium(III) and iridium(III, IV) by anion exchange

ZusammenfassungDas dünnschicht-chromatographische Verhalten von Rh(III), Ir(III) und Ir(IV) wurde in H2O2-haltiger 5 M salzsaurer Lösung auf DEAE-sowie ECTEOLA-Cellulose untersucht. In Kombination mit einer einfachen chemischen Vorbehandlung der Probe (mit LiCl, HCl, H2O2) kann eine wirkungsvolle Trennung von Rh(III) und Ir(III) oder Ir(IV) über einen weiten Konzentrationsbereich erzielt werden (Rh: Ir=1∶100 bis 100∶1).SummaryThe TLC behaviour of Rh(III), Ir(III) and Ir(IV) has been investigated in the two systems consisting of DEAE-cellulose or ECTEOLA-cellulose and 5 M HCl media containing H2O2. These systems, especially in combination with a simple chemical pretreatment of samples (with LiCl, HCl and H2O2), can effectively be applied to the complete separation of mixtures of Rh(III) and Ir(III) or Ir(IV) in a wide range of ratios and amounts (Rh: Ir=1∶100 to 100∶1).

Thin-layer chromatographic separation of noble metals on ECTEOLA-cellulose in hydrochloric acid and aqueous chloride solutions

ZusammenfassungDas Verhalten von Edelmetallen wurde in salzsauren Lösungen sowie in Lösungen der Chloride von Li, Na, Mg, Ca, Sr und Al geprüft. Die Rf-Werte nehmen in allen Medien mit höherer Chlorid-konzentration (3M bis 5M) in folgender Reihenfolge ab: Ir(III) ≥ Rh(III) > Ru(III) > Pd(II) > Pt(IV) > Ir(IV) > Au(III). Die Unterschiede in den Rf-Werten sind groß genug, um eine deutliche Trennung zu gewährleisten. Salzsaure Lösungen mit oder ohne H2O2-Zusatz sind besonders gut für die Trennung von Vielkomponenten-Gemischen geeignet.SummaryThe thin-layer chromatographic behaviour of the noble metals on ECTEOLA-cellulose has been examined in HCl and aqueous chloride solutions of Li, Na, Mg, Ca, Sr and Al. The Rf-values decrease in the order Ir(III) ≥ Rh(III) > Ru(III) > Pd(II) > Pt(IV) > Ir(IV) > Au(III) in all of the media of higher chloride concentrations (3M to 5M), in which there are sufficiently large differences in Rf-values of adjacent metals to resolve them clearly. Especially, the HCl solutions with or without H2O2 are very suitable for multi-component separations of the noble metals.

Consecutive thin-layer chromatographic separation of Au(III), Pt(IV), Pd(II) and large amounts of associated base metals

SummaryThe TLC system composed of ECTEOLA-cellulose and 2.5 mol/l HCl−2.5 mol/l NaCl−0.6% (w/v) H2O2 solution allows consecutive separations of Au(III), Pt(IV), Pd(II) and a number of associated base metals such as Cr(III), Mn(II), Fe(III), Co(II) Ni(II), Cu(II), Mg, Ca, Ba, Al, Bi(III), Pb(II), Zn(II) and Ag(I) coexisting in an extremely wide range of amounts and ratios, to be conducted completely in a single run. The effectiveness of the present system is verified by applying it to various synthesized samples containing the three noble metals and one of the base metals, Pt-metal powder and two kinds of Au-alloys.

Anion-exchange TLC of rhodium(III) and iridium(III,IV) on DEAE-cellulose or ECTEOLA-cellulose

ZusammenfassungZur dünnschicht-chromatographischen Trennung von Rh und Ir wurden DEAE- bzw. ECTEOLA-Cellulose mit 3 M bzw. 5 M NaClO3-haltiger Salzsäure als Lösungsmittel benutzt. Besonders in Verbindung mit einer Probevorbehandlung mit LiCl, HCl und H2O2 konnten mit diesen Systemen scharfe Trennungen von Rh(III), Ir(III) und Ir(IV) in einem weiten Konzentrationsbereich erzielt werden (Rh∶Ir=1∶500 bis 200∶1). Das Adsorptionsverhalten des Rh(III) in Abhängigkeit von der Vorbehandlung der Probelösung wird diskutiert.SummaryThe TLC behaviour and separation of Rh(III), Ir(III) and Ir(IV) has been investigated in the two systems composed of DEAE-cellulose or ECTEOLA-cellulose using 3 M or 5 M HCl containing NaClO3 as solvent. These systems, especially in combination with a sample treatment with LiCl, HCl and H2O2 solutions, allow the clean-cut separations of Rh(III) from Ir(III) as well as Ir(IV), coexisting in an extremely wide range of amounts and ratios (Rh∶Ir=1∶500 to 200∶1). A brief discussion on the characteristic adsorption behaviour of Rh(III), dependent on the previous history of the sample solutions, is also included.

Thin-layer chromatographic separation of alkaline earth metals on microcrystalline cellulose

The thin-layer chromatographic behaviour of all the alkaline earth metals except for radium on microcrystalline cellulose in methanol-nitric acid media has been investigated. The R(f) values increase in the order beryllium > magnesium > calcium > strontium > barium. The five metals can be effectively separated from each other with methanol-14M nitric acid (3:1, v/v). The system is also suitable for the separation of mixtures of two metal ions existing in widely varying proportions.

Anion-exchange separation of rhodium and iridium by ECTEOLA-cellulose column

SummaryThe separation of Rh(III) and Ir(IV) in amounts of 20–5300 and 20–7700 μg, respectively, and in ratios of Rh∶Ir=1∶100 to 100∶1 was achieved without cross-contamination by use of a 3 g ECTEOLA-cellulose column. Rh was first eluted with 40 ml of a 3 mol/l HCl-1% (w/v) NaClO3 solution. Ir(IV) was desorbed with 60 ml of a 6 mol/l HCl-0.1% (w/v) NaClO3 solution. Quantitative recoveries were obtained for each metal. The present method provides much better resolution than the other existing anion-exchange methods and can effectively be applied to the separations and recoveries of Rh and Ir(III or IV) present in a more extensive range of amounts and ratios.