R.K. Bansal

Spectrophotometric determination of osmium with 1-phenyl-4,4,6-trimethyl-(1H,4H)-2-pyrimidinethiol and extraction into molten naphthalene

Conditions have been developed for the spectrophotometric determination of osmium with 1-phenyl-4,4,6-trimethyl-(1H,4H)-2-pyrimidinethiol after extraction of the complex into molten naphthalene. Beers law holds for the concentration range of 4-77 mug of osmium in 10 ml of the final solution. The molar absorptivity is 1.33 x 10(4) l.mole(-1).cm(-1). The reagent is highly selective for osmium.

Extractive spectrophotometric determination of chromium(III) with phenanthrenequinone monoxime into molten naphthalene

Abstract Conditions have been developed for the determination of chromium after extraction of its phenanthrenequinone monoximate into molten naphthalene in the presence of potassium chloride. The solidified naphthalene-containing chromium complex was dissolved in chloroform and the trace amounts of chromium determined spectrophotometrically. Beers law holds in the concentration range of 5.2–84.3 μg in 10 ml of the chloroform solution. The molar absorptivity and sensitivity (for an absorbance of 0.001) are calculated to be 6.65 × 10 3 liters mol −1 cm −1 and 0.00782 μg/cm 2 . Ten replicate solutions containing 31.2 μg of chromium(III) gave a mean absorbance of 0.399 with a relative standard derivation of 0.00497. Interference of various ions has been studied and the method applied for the determination of chromium(III) in certain alloys.

Spectrophotometric determination of iridium (III) and osmium (VIII) with phenanthrenequinone monoxime after extraction into molten naphthalene

SummaryConditions have been established for the extraction of iridium (III) and osmium(VIII) as their phenanthrenequinone monoximates into molten naphthalene. The naphthalene is allowed to solidify, separated by filtration, dried with filter paper and dissolved in chloroform. The absorbance is measured at 470 nm for iridium and 475 nm for osmium. Beers law is obeyed in the concentration ranges 3.2–38.6μg of iridium and 1.0–10.9μg of osmium in 10 ml of chloroform. The molar absorptivities are 2.3×104 and 8.8×104l. mole−1.cm−1 for iridium and osmium respectively. The optimum pH range for the extraction is 4.6–7.4 for iridium and 6.8–10.5 tor osmium. Interferences have been studied in detail and the method successfully applied to various synthetic mixtures. The two metals can be determined sequentially (in the absence of interfering ions), osmium first.ZusammenfassungDie Extraktionsbedingungen für Ir(III) und Os(VIII) als Phenanthrenchinonmonoximate mit geschmolzenem Naphthalin wurden ermittelt. Man läßt das Naphthalin erstarren, filtriert es, trocknet es mit Filterpapier und löst es in Chloroform. Die Absorbanz wird bei 470 nm gemessen für Ir und bei 475 nm für Os. Das Beersche Gesetz gilt für Ir im Konzentrationsbereich 3,2–38,6μg und für Os zwischen 1,0 und 10,9μg/10 ml Chloroform. Die molare Absorption beträgt 2,3×104 bzw. 8,8×104l·mol−1·cm−1 für Ir bzw. Os. Das optimale pH-Gebiet für die Extraktion von Ir liegt bei 4,6–7,4, für Os bei 6,8–10,5. Störungen wurden im Detail untersucht und das Verfahren mit Erfolg für verschiedene Gemische angewendet. In Abwesenheit störender Ionen können Osmium und Iridium hintereinander bestimmt werden.

Spectrophotometric determination of palladium after coprecipitation of its 9,10-phenanthrenequinone monoximate on microcrystalline naphthalene

SummaryA spectrophotometric method has been developed for the microdetermination of Pd(II) as its 9,10-Phenanthrenequinone monoximate, by coprecipitation on solid naphthalene and dissolution in chloroform. The method can be applied to the determination of palladium in certain synthetic mixtures.ZusammenfassungEin spektrophotometrisches Verfahren zur Mikrobestimmung von Pd(II) als 9,10-Phenanthrenchinonmonoximat durch Mitfällung auf festes Naphthalin und Lösung in Chloroform wurde ausgearbeitet. Dieses Verfahren eignet sich zur Bestimmung von Palladium in gewissen synthetischen Gemischen.

Trifluoroethylxanthate as an analytical reagent: Spectrophotometric determination of cobalt and copper as their trifluoroethylxanthates

SummaryA direct spectrophotometric method has been developed for the micro-determination of Co(II) and Cu(II) as their trifluoroethylxanthates, by use of aqueous acetone medium. The reagent and methods have been found selective and sensitive for the determination of these metals in certain alloys.ZusammenfassungEine direkte spektrofluorimetrische Methode zur Mikrobestimmung von Co(II) und Cu(II) in Form ihrer Trifluorethylxanthate in wäßrigem Acetonmedium wurde ausgearbeitet. Reagens und Methode sind bei der Bestimmung der genannten Metalle in gewissen Legierungen selektiv und empfindlich.