High-performance thin-layer chromatographic method for the determination of chlorpyrifos and its metabolite in visceral samples

JPC – Journal of Planar Chromatography – Modern TLC - In an attempt to determine chlorpyrifos insecticide and its metabolite 3,5,6-trichloropyridinol in visceral samples, a rapid...     

Milligram level determination of mercury(II) and bismuth (III): p-mercaptoacetamidophenetidine as a gravimetric reagent

Summary The gravimetric estimation of mercury(II) and bismuth(III) has been carried out on a mg scale usingp-mercaptoacetamidophenetidine as the precipitant. The reagent has the required aqueous solubility and is superior to the commonly used analytical reagents of the mercaptan family. The complexes of the reagent with mercury(II) and bismuth(III) are obtained in pure state, definite in composition and stable in hot acid media.

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Zusammenfassung Die gravimetrische Bestimmung von Hg(II) und Bi(III) mit p-Mercaptoacetamidophenetidin als Fällungsmittel wurde ausgearbeitet. Dieses Reagens ist den üblicherweise verwendeten Merkaptanen überlegen. Die KomplexVerbindungen mit Hg und Bi erhält man rein und in definierter Zusammensetzung. Sie sind gegenüber heißer Säure beständig.

     

Determination of silver,gold, palladium,and platinum on milligram scale: m-(mercaptoacetamido)phenol as gravimetric reagent

Summary A method for the gravimetric determination of milligram quantities of Ag(I), Au(III), Pd(II), and Pt(IV) is presented. It is based on precipitation of the respective chelates withm-(mercaptoacetamido)phenol. Procedures for the analysis of binary and ternary mixtures are described.

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Zusammenfassung Die gravimetrische Bestimmung von Milligrammengen Ag(I), Au(III), Pd(II) und Pt(IV) durch Fällung ihrer Chelate mit m-Merkaptoacetamidophenol wird vorgeschlagen. Arbeitsvorschriften für die Analyse binärer oder ternärer Gemische wurden angegeben.

     

Multiplicity formulas for finite dimensional and generalized principal series representations

The article presents two results. (1) Let a be a reductive Lie algebra over ℂ and let b be a reductive subalgebra of a. The first result gives the formula for multiplicity with which a finite dimensional irreducible representation of b appears in a given finite dimensional irreducible representation of a in a general situation. This generalizes a known theorem due to Kostant in a special case. (2) LetG be a connected real semisimple Lie group andK a maximal compact subgroup ofG. The second result is a formula for multiplicity with which an irreducible representation ofK occurs in a generalized representation ofG arising not necessarily from fundamental Cartan subgroup ofG. This generalizes a result due to Enright and Wallach in a fundamental case.     

Pechmann reaction of 4-hydroxycoumarins and thiocoumarins with cyclohexanone and ethyl cyclopentanone-2-carboxylates

The Pechmann reaction of 4-hydroxycoumarins with cyclohexanone and ethyl cyclopentanone-2-carboxylates affords 1,2,3,4-tetrahydro[2]benzopyrano[4,3-c][1]benzopyran-5,12-diones and cyclopenta[3′,4′]pyrano-[3,2-c][1]benzopyran-4,11-diones. Dehydrogenation of the former yields [2]benzopyrano[4,3-c][1]benzopyran-5,12-diones. Alkaline hydrolysis of a typical compound Va affords 2-hydroxy-2′-carboxydeoxybenzoin which on boiling with acetic anhydride gives an isocoumarin derivative.