Spectrophotometric Determination of Piroxicam via Chelation with Fe(III) in Commercial Dosage Forms

The objective of this work is to develop and validate spectrophotometric method for the determination of piroxicam in commercial dosage forms. The method is based on the chelation of the drug with Fe(III) to form pink coloured metal chelate at room temperature which absorbs maximally at 504 nm. Beer's law is obeyed over the concentration range of 8–160 μg mL^?1 (A = 1.07 × 10^?3 + 7.75 × 10^?3 C). Under the optimized experimental conditions, proposed method is validated as per the International Conference on Harmonisation guidelines. The limits of detection and quantitation for the proposed method are 0.775 and 2.348 μg mL^?1, respectively. The proposed method has been successfully applied to the determination of piroxicam in commercial dosage forms. The results are compared with the reference El‐Ries et al. spectrophotometric method.     

Nonlinear fractional differential equations of Sobolev type

Sobolev type nonlinear equations with time fractional derivatives are considered. Using the test function method, limiting exponents for nonexistence of solutions are found. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis,characterization and biological activities of organotin(IV) complexes with l-lysine monohydrate

Russian Journal of General Chemistry - The new organotin(IV) complexes have been synthesized by the reaction of l-lysine monohydrate with CS2 and R2SnCl2/R3SnCl. The organotin(IV) complexes and the...     

The monotone iterative technique for impulsive hybrid set valued integro-differential equations

We develop the monotone method for impulsive hybrid set integro-differential equations in all its generality. Some interesting observations are presented.     

Titrimetric and spectrophotometric methods for the determination of cerium(IV) in aqueous solution

A titrimetric and spectrophotometric methods for cerium(IV) determination have worked out. The first method relies upon the treatment of cerium(IV) solution with an excessive amount of iodide; the liberated iodine is extracted into chloroform, then reduced to iodide. The latter is iodometrically determined after 6- or 36-fold amplification. The spectropho-tometric finish is based upon the reaction of the titled ion with iron(II), in the presence of hexacyanoferrate(II), to form an intense prussian blue color suitable for the trace determination of cerium(IV) ion.     

On multi-term fractional differential equations with multi-point boundary conditions

In this paper, we discuss the existence and uniqueness of solutions for a new class of multi-point boundary value problems of multi-term fractional differential equations by using standard fixed point theorems. We also demonstrate the application of the obtained results with the aid of examples. The paper concludes with the study of multi-term fractional integro-differential equations supplemented with multi-point boundary conditions. Our results are new and contribute significantly to the existing literature on the topic.     

Indirect spectrophotometric determination of chromium(VI)

A new simple and sensitive spectrophotometric method for the determination of chromium(VI) is established. It relies upon the oxidation of iron(II) with the titled ion, in acidic medium, to form iron(III) which is complexed with tiron to form a stable blue color with maximum absorption at 650 nm. Adherence to Beer's law is observed in the range 10–100 μg of chromium(VI) per 25 ml, with a molar absorptivity of 5.6 × 10³ liters mol^?1 cm^?1, sensitivity index of 0.0093 μg cm^?1, relative error of ?5.0 to +0.3%, and relative standard deviation of 0.3–4.0%, depending on the concentration level. Furthermore, the reaction needs neither temperature control nor an extraction step.     

Determination of starane (fluroxypyr) herbicide using flow injection spectrophotometry.

The starane herbicide was spectrophotometrically determined by the diazotization method in a flow injection assembly. Since starane is a substituted pyridyl compound the NH2 group at the p-position was exploited for diazotization. Starane was diazotized with nitrite and the diazotized product is coupled with beta-naphthol. The absorbance of the resulting azo dye was measured at 395 nm with a molar absorptivity of 1.5 x 10(4) L mol(-1) cm(-1). The calibration graph was linear over the range of 0.6 to 10 microg/mL, with a relative standard deviation (RSD) of 1.67% and a sampling through put of 60 samples h(-1). The % recovery for the determination of starane was found to be 96%. The method was successfully applied to the determination of the active ingredient of starane herbicide in its formulation as well as in food samples.