Palladium determination

P-10 gas, 45, 219 Pair production, 290 Palladium, determination by x-ray emission spectrography, 328 Particle size, effect of variations of, in mineral analysis, 200 Philips Autrometer, 252-256, 280 Philips Electronics gas analyzer, 135 Philips Electronics improved Coolidge tubes, 248, 252, 253... 

Zhang Li., Zhe-Ming N. and Xiao-Quan S. (1989) In situ concentration of metallic hydride in a graphite furnace coated with palladium -determination of bismuth, germanium and tellurium, Spectrochim Acta, Part B 44 751-758. 

A considerable increase in the sensitivity of methods for palladium determination has been found with triphenylmethane reagents in ternary systems that include cationic surfactants, e.g., Eriochrome Cyanine R with CP [79], Chromal Blue G with CTA (e = 1.0-10 ) [80], Chrome Azurol S-CTA (or -CP) [81], Eriochrome Azurol B-CTA (e = 1.15-10 ) [82], and Eriochrome Azurol G-CTA [83]. 

A number of years later, Khalifa et al.9 proposed pallatriazo as a very sensitive reagent for palladium determination ... 

Instrumental Neutron Activation Analysis (INAA) was applied to the determination of the platinum metals as part of a study of their uptake, accumulation and toxicity in plants. Long irradiations are described for iridium, osmium and ruthenium determinations in specially grown plant materials. An interference in the determination of platinum in plant matrices by this method is reported also. Short irradiations, utilising thermal and epithermal fluxes are investigated for rhodium and palladium determinations, with further studies using cyclic activation analysis. 

Resano, M, Garcla-Ruiz, E., Crespo, C, Vanhaecke, F. Belarra, M.A. (2003) Sohd sampling-graphite furnace atomic absorption spectrometry for palladium determination at trace and ultra trace levels. J. Anal At. Spectrom., 18, 1477-1484. 

Scholten J J and van Montfoort A 1962 The determination of the free-metal surface area of palladium catalysts J. Catal. 1 85-92... 

This reagent, to which the name nioxime has been given, ia employed for the determination of palladium and may also be used for nickel it is soluble in water, and possesses advantages over dimethylglyoxime. The latter is used as a solution in alcohol and may therefore contaminate the palladium or nickel precipitate when added to an aqueous solution. 

NMR signals of the amino acid ligand that are induced by the ring current of the diamine ligand" ". From the temperature dependence of the stability constants of a number of ternary palladium complexes involving dipeptides and aromatic amines, the arene - arene interaction enthalpies and entropies have been determined" ". It turned out that the interaction is generally enthalpy-driven and counteracted by entropy. Yamauchi et al. hold a charge transfer interaction responsible for this effect. 

SORPTION-CATALYTIC DETERMINATION OF MICRO-AMOUNT AND CHEMICAL STATE OF PALLADIUM ON SURFACE OF CARBON ADSORBENT... 

It was found that sorbed palladium might catalyse reaction of Mn(III) reduction by Cf not only after it s removing from coal, but AC with palladium, Pd/AC, has also his own catalytic effect. On the base of dependence between characteristics of AC, chemical state of palladium on AC surface and catalytic action of Pd/AC in indicator reaction it might establish, that catalytic action concerns only to non-reduced or partly reduced palladium ions connected with chloride ions on coal surface. The presence or absence of catalytic action of Pd/AC in above-mentioned reaction may be proposed for determination of chemical state of palladium on AC surface. Catalytic effect was also used for palladium micro-amounts determination by soi ption-catalytic method. 

Consequent potentiometric titration of osmium(IV) and laithenium (IV) in their mixtures has been canied out in broad range of concentrations from 1 mkg to 200 mkg in samples of 20 ml. It has been shown the possibility of amperemetric determination of osmium(VI) in binary and triple systems with silver(I), platinum(IV), palladium(II), gold(III), founded on formation of corresponding compounds with dimerkaptotiopiron, having a different solubility. The deteriuination of Os(VI) is possible under tenfold - hundredfold excess of above mentioned metals. 

For the increase of sensitiveness of the voltamperometric determination Co(II) use o,o -dihydroxysubstituted azodyes (eriochrome red B and calces). The Co(II) determination can be conducted at potential of reduction of coordinating connection of Co(II)-azodye (E = - 0,9V) and directly the Co(II) (E = -1,2V, ammonia buffer solution) ions. The results of reseaixhes show that selectivity of the Co(II) determination in presence the Ni(II) and Pd(II) ions more high with the use of analytical signal at the potential -1,2V. Is it thus succeeded move aside potentials of peaks of reduction of the Ni(II) and Co(II) ions on a background ammoniac buffer solution from AE=0,2V to AE = 0,4-0,5V. The Co(II) determination can be conducted in presence 50-100 multiple surpluses Ni(II). Palladium in these conditions does not prevent to 60 multiple surplus. 

As catalyst for the Rosenmund reaction palladium on a support, e.g. palladium on barium sulfate, is most often used. The palladium has to be made less active in order to avoid further reduction of the aldehyde to the corresponding alcohol. Such a poisoned catalyst is obtained for example by the addition of quinoline and sulfur. Recent reports state that the reactivity of the catalyst is determined by the morphology of the palladium surface." ... 

Selectivity depends importantly on the catalytic metal. A number of selectivity series have been determined for simple olefins, and the presumption is that the sequence holds for more complex polyenes as well. Selectivity for the reduction of allene to propylene declined with metal in the order palladium... 

Two hydrogen-transfer systems have been developed that also give good yields of hydroxylamines. One uses 5% palladium-on-carbon in aqueous tetrahydrofuran with phosphinic acid or its sodium salt as hydrogen donor the other uses 5% rhodium-on-carbon in aqueous tetrahydrofuran and hydrazine as donor. These systems are complementary and which is the better may depend on the substrate (36). The reductions cannot be followed by pressure drop, and both require analysis of the product to determine when the reduction should be terminated. 

A potential pH diagram for the Pd-HjO-Cl system is presented and described whilst the rest potentials of palladium electrodes in oxygen-saturated solutions of different pH values have been determined . From the latter, dEr/dpH = — 65 mV in acid and —35 mV in alkaline solutions, and dEr/dlgPoj = 30 mV for both pH ranges. 

A half-cdl consisting of a palladium rod dipping into a 1 M Pd(NOj)2 solution is connected with a standard hydrogen half-cell. The cell voltage is 0.99 volt and the platinum dectrode in the hydrogen half-cell is the anode. Determine E° for the reaction... 

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