The effect of varying short-chain alkyl substitution of the indole nitrogens on the spectroscopic properties of cyanine dyes was examined. Molar absorptivities and fluorescence quantum yields were determined for a set of pentamethine dyes and a set of heptamethine dyes for which the substitution of the indole nitrogen was varied. For both sets of dyes, increasing alkyl chain length resulted in ...

A rapid and simple spectrophotometric procedure is described for the determination of ajmaline and brucine. The method is based on the development of blue coloured product due to reduction of tungstate and/or molybdate in Folin Ciocalteu’s reagent (FCR) by ajmaline and brucine in alkaline medium. The colour is stable for more than 48 h. The chromogenic reaction has max at 540 nm with molar abso...

A simple and highly sensitive spectrophotometric method for the determination of anthracycline anticancer agents, such as Daunorubicin hydrochloride (DAU), was established by using aluminum(III) and Chromazurol S (CAS) in a nonionic surfactant micellar medium. In the case of determination of DAU, the apparent molar absorptivity was 1.3 x 10(5) dm3 mol(-1) cm(-1) at 615 nm. Beer's law was obeyed...

A simple and highly sensitive method is proposed for determination of trace amount of cerium. New method involves bleaching of greenish colour dye-malachite green, by the action of iodine, which is released by reaction between potassium iodide and cerium (IV) in acidic medium. Beer’s law is obeyed over concentration range of 0.6 to 4.6 μg cerium (IV) in final volume of 25 ml (0.024-0.184 ppm). ...

Serum alkaline phosphatase estimations by the Selected Method [Clin. Chem. 21, 1988 (1975)] are very sensitive to small errors in the wavelength setting of the spectrophotometer. With a setting error as small as 3 nm, results can be too low by as much as 23%. The product of the reaction, 4-nitrophenol, can be prepared in very pure form and can be used to check both the wavelength and absorbance...

Two novel methods are presented for the spectrophotometric determination of colchicoside (COLSID). Method A involves the reaction of COLSID with Fe(III) to form complex and method B is based on the reaction of the drug with NH2OH.HCl, the absorbances of which are measured at 458 nm and 395 nm respectively. The calibration graphs are found to be linear over 20.00-120.00 and 20.00-100.00 μgmL for...

A spectrophotometric method has been developed for the determination of Cu(II) using Acetophenone 2’,5’dihydroxy, semicarbazone as an extractive reagent .The reagent forms a colored complex which has been quantitatively extracted into n-Butanol at pH 5.6. The method obeys Beer’s law over a range of 1 to 10 ppm. The molar absorptivity is 2564.1 L molcm and Sandell’s sensitivity is 0.02484 μg cm ...

A b s t r a e t A method using 1,10-phenanthroline (phen) to quantify Fe(II) and total Fe in nonrefractory minerals was modified to improve the accuracy and precision and to eliminate the inconvenience of performing much of the analysis under darkroom conditions. Reagents were combined to minimize solution-handling errors, volumes of the reagent additions were determined gravimetrically and the...

Semiconductor quantum dots exhibit great potential for applications in next generation high efficiency, low cost solar cells because of their unique optoelectronic properties. Cu(2)ZnSnS(4) (CZTS) nanocrystals and graphene quantum dots (GQDs) have recently received much attention as building blocks for use in solar energy conversion due to their outstanding properties and advantageous character...

It is reported that the ductility and strength of a metal matrix composite could be concurrently improved if the reinforcing particles were of the size of nanometers and distributed uniformly. In this paper, we revealed that gas atomization solidification could effectively disperse TiB2 nanoparticles in the Al alloy matrix due to its fast cooling rate and the coherent orientation relationship b...