Second Order Derivative Spectrophotometric Method Research Articles

Second-Order Derivative Spectrophotometric Method for Simultaneous Estimation of Azilsartan Medoxomil and Cilnidipine in Combined Dosage Form

Second-Order Derivative Spectrophotometric Method for Simultaneous Estimation of Azilsartan Medoxomil and Cilnidipine in Combined Dosage Form

Simultaneous removal of anionic dyes onto Mg(Al)O mixed metal oxides from ternary aqueous mixture: Derivative spectrophotometry and Density Functional Theory study

A simultaneous removal of Eriochrome Black T (EBT), Indigo Carmine (IC) and Methyl Orange (MO) anionic dyes in ternary mixture onto mixed metal oxides (Mg(Al)O) was studied. Mg(Al)O nanoparticles were obtained through one-step by pyrolysis of MgAl-layered double hydroxide compound as precursor. In view of the significant interferences in visible light absorbance, second-order derivative spectrophotometric method was adopted for simultaneous analysis of MO, EBT and IC concentrations. Thermodynamic parameters indicated that the removal of the three anionic dyes were exothermic and spontaneous in nature. Theoretical studies carried out on the dyes structures using density functional theory (DFT) calculations were of use to evaluate the relative electron donating/accepting character of each dye molecule, and are in good agreement with experimental data. Quantum chemical results suggested that MO (N = 4.2414) is more nucleophilic than EBT (N = 3.7960) and IC (N = 3.9797); the assumption has been that MO molecules were favorably adsorbed and interacted first with Mg(Al)O nanoparticles in the mixture media. Moreover, according to the local molecular reactivity results the nitrogen atoms, exhibiting the higher nucleophilic Parr functions PK−, could be the main active sites. In the light of these results, a possible removal mechanism was suggested.

Simultaneous ultrasonic-assisted removal of malachite green and methylene blue from aqueous solution by Zr-SBA-15

In this study, simultaneous and competitive removal of methylene blue (MB) and malachite green (MG) dyes was performed by employing nanostructure Zr-SBA-15, once using solid-phase extractionmethod (SPE) and again using ultrasonic bath, followed by second-order derivative spectrophotometric method in order to resolve the corresponding overlapped spectra. Zr-SBA-15 characterized by FT-IR, XRD, BET, SEM and EDX techniques. Using the proposed procedure, removal of the mentioned dyes was carried out in the minimum time. Moreover, some of the most influential parameters including the initial concentration of MB and MG, dosage of the absorbent, sonication time and pH of the medium were optimized using central composite design (CCD) in response surface methodology (RSM). Desirability scores demonstrated the optimal conditions as follows: sonication time of 4.78 min, adsorbent dosage of 6.66 mg, pH of 7.15 and initial concentrations of 10.21 and 5.48 mg L−1 for MB and MG, respectively. Under optimum conditions, maximum adsorption capacities of 310.88 and 140.61 mg g−1 were achieved for MB and MG, respectively. Kinetic studies and calculation of relevant equations from kinetic graphs and isotherm exhibited simultaneous adsorption of the desired dyes, followed by pseudo-second order spectrophotometric method and Langmuir isotherm.

Simultaneous determination of Cefixime trihydrate and Ofloxacin in pharmaceutical dosage form by second order derivative UV spectrophotometry

Derivative spectrophotometry offers a useful approach for the analysis of drugs in multi-component formulation. In this study a second order derivative spectrophotometric method is applied for the simultaneous determination of Cefixime Trihydrate and Ofloxacin in Tablet dosage form. The measurements were carried out at wavelengths of 307 and 298 nm for Cefixime Trihydrate and Ofloxacin respectively. The method was found to be linear (r=0.999) in the range of 4-20 ?g/ml for Cefixime Trihydrate in the presence of 20 ?g/ml of Ofloxacin at 307 nm. The linear correlation (r=0.999) was obtained in the range of 4-20 ?g/ml for Ofloxacin in the presence of 20 ?g/ml of Cefixime Trihydrate at 298 nm. The method was successfully used for simultaneous determination of Cefixime Trihydrate and Ofloxacin in tablet dosage form without any interference from excipients and prior separation.

Spectrophotometric determination of chlorthalidone in pharmaceutical formulations using different order derivative methods

Simple, repaid and accurate zero-, first- and second-order derivative spectrophotometric methods have been developed for determination of chlorthalidone (CLT) in commercially available tablets. Normal spectrophotometric scan (zero order) shows maximum absorbance at 276nm in methanol solution and a good linearity in the range of 10.0–75.0μg/mL. Linear relations using first (D1) and second (D2) order derivative methods were obtained at 278 and 288nm for D1 and 286 and 292nm for D2.The calibration curves were constructed in the range of 1.0–25.0μg/mL for D1 (R=0.998) and D2 (R=0.999). Different analytical validations were determined (accuracy, precision, specificity, recovery, stability and robustness) to demonstrate its suitability for routine quality control labs. All the developed methods were successfully applied to a tablet formulation and the results were compared statistically with each other and with those obtained by the HPLC reference method.

Spectrophotometric Determination of Gold(III) Using 2-Hydroxy-3-Methoxy Benzaldehyde Thiosemicarbazone as a Chromophoric Reagent

A chromophoric reagent, 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC), was employed for the sensitive spectrophotometric determination of gold(III). The gold(III) ion forms a blue-coloured complex with HMBATSC in an aqueous dimethyl formamide at pH 6.0. The gold complex shows the absorption maximum at 385 nm, and Beer's law was obeyed in the range 0.49–8.37 μg mL−1. The molar absorptivity and Sandell's sensitivity were found to be L mol−1 cm−1 and 0.015 μg cm−2, respectively. The complex shows 1 : 1 [Au(III) : HMBATSC] stoichiometry with a stability constant of . The interference effect of various diverse ions has been studied. In addition to zero-order, first- and second-order derivative spectrophotometric methods were also developed for the determination of gold(III) in microgram amounts which were more sensitive than the zero-order method. The developed method has been used for the determination of gold(III) in environmental water samples and certified reference materials. The results were in excellent agreement with the certified values.

Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone.

Optimized and validated spectrophotometric methods have been proposed for the determination of iron and cobalt individually and simultaneously. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) reacts with iron(II) and cobalt(II) to form reddish-brown and yellow-coloured [Fe(II)-HNAHBH] and [Co(II)-HNAHBH] complexes, respectively. The maximum absorbance of these complexes was found at 405 nm and 425 nm, respectively. For [Fe(II)-HNAHBH], Beer's law is obeyed over the concentration range of 0.055–1.373 μg mL−1 with a detection limit of 0.095 μg mL−1 and molar absorptivity ɛ, 5.6 × 104 L mol−1 cm−1. [Co(II)-HNAHBH] complex obeys Beer's law in 0.118–3.534 μg mL−1 range with a detection limit of 0.04 μg mL−1 and molar absorptivity, ɛ of 2.3 × 104 L mol−1 cm−1. Highly sensitive and selective first-, second- and third-order derivative methods are described for the determination of iron and cobalt. A simultaneous second-order derivative spectrophotometric method is proposed for the determination of these metals. All the proposed methods are successfully employed in the analysis of various biological, water, and alloy samples for the determination of iron and cobalt content.

An application of second-order UV-derivative spectrophotometry for study of solvolysis of a novel fluocinolone acetonide ester

A novel topical corticosteroid FA-21-PhP, 2-phenoxypropionate ester of fluocinolone acetonide, has been synthesized in order to investigate the possibility of decreasing systemic side effects. In this study model system for in vitro solvolytic reaction of FA-21-PhP has been analyzed in ethanol/water (90:10, v/v) with excess of sodium hydrogen carbonate. The selected conditions have been used as in vitro model for activation of corticosteroid C-21 ester prodrug. The second-order derivative spectrophotometric method (DS) using zero-crossing technique was developed for monitoring ternary mixture of solvolysis. Fluocinolone acetonide (FA) as a solvolyte was determined in the mixture in the concentration range 0.062–0.312 mM using amplitude 2D 274.96. Experimentally determined LOD value was 0.0295 mM. The accuracy of proposed DS method was confirmed with HPLC referent method. Peak area of parent ester FA-21-PhP was used for solvolysis monitoring to ensure the initial stage of changes. Linear relationship in HPLC assay for parent ester was obtained in the concentration range 0.054–0.54 mM, with experimentally determined LOD value of 0.0041 mM. Investigated solvolytic reaction in the presence of excess of NaHCO 3 proceeded via a pseudo-first-order kinetic with significant correlation coefficients 0.9891 and 0.9997 for DS and HPLC, respectively. The values of solvolysis rate constant calculated according to DS and HPLC methods are in good accordance 0.038 and 0.043 h −1, respectively.

Determination of mirtazapine in tablets by UV spectrophotometric and derivative spectrophotometric methods

Mirtazapine, 1, 2, 3, 4, 10, 14b-hexahydro-2-methyl-pyrazino [2, 1-a] pyrido [2, 3-c] [G.L. Stimmel, J.A. Dopheide and S.M. Stahl, Pharmacotheraphy 17(1) (1997) 10] benzazepine, is a new and well tolerated antidepressant. It blocks pre-synaptic α 2-adrenergic receptors and postsynaptic serotonin type 2 and type 3 receptors. The drug is rapid and completely absorbed after oral administration. Mirtazapine was analyzed by HPLC and gas chromatography with nitrogen-sensitive detection. In this study, mirtazapine was analyzed by using UV spectrophotometry, first and second order derivative spectrophotometry. The type of solvent, the degree of derivation, range of wavelength and n value were chosen in order to optimize the conditions. The concentration of mirtazapine in its methanolic solutions were determined between the wavelength range of 225–360 nm in the linearity range of 1–100, 2–100 and 1–120 μg ml −1 by using the values obtained from UV, first-order derivative ( n=5, Δ λ=17.5 nm) and second-order derivative ( n=9, Δ λ=31.5 nm) spectrum of the substance, respectively. The developed UV Spectrophotometric, first-order and second-order derivative spectrophotometric methods were applied to a pharmaceutical preparation as tablet form. Developed UV and derivative UV spectrophotometric method in this study are accurate, sensitive, precise, reproducible and can be directly and easily applied to the pharmaceutical preparations.

Simultaneous determination of benazepril hydrochloride and hydrochlorothiazide in tablets by second-order derivative spectrophotometry

A second-order derivative spectrophotometric method for the simultaneous determination of benazepril hydrochloride and hydrochlorothiazide in pharmaceutical dosage forms is described. The determination of benazepril hydrochloride in the presence of hydrochlorothiazide was achieved by measuring the second-order derivative signals at 253.6 and 282.6 nm, while the second-order derivative signal at 282.6 nm was measured for the determination of hydrochlorothiazide. The linear dynamic ranges were 14.80–33.80 μg ml −1 for benazepril hydrochloride and 18.50–42.20 μg ml −1 for hydrochlorothiazide, the correlation coefficient for the calibration graphs were better than 0.9998, n=5, the precision (%RSD) was better than 1.43% and the accuracy was satisfactory ( E r<0.99%). The detection limits were found to be 2.46 and 1.57 μg ml −1 for benazepril hydrochloride and hydrochlorothiazide, respectively. The method was applied in the quality control of commercial tablets and proved to be suitable for rapid and reliable quality control.

Determination of Americium in a Nitric Acid Medium Using Second-Order Derivative Spectrophotometry.

A second-order derivative spectrophotometric method has been developed for the determination of microgram quantities of trivalent americium in a nitric acid medium containing plutonium and uranium. The second-order derivative absorbance of the americium at 503.5nm is used for the quantitative analysis. In the determination of 5.8μg/ml and 3.9μg/ml of americium, the presence of a 100-fold amount of plutonium and a 600-fold amount of uranium could be tolerated, respectively. The trivalent americium, in the concentration range of 1-11μg/ml has been determined with good precision. The detection limit was 0.3μg/ml at 3 times the standard deviation (3σ). The relative standard deviation was less than 2.1% for a sample of uranium-plutonium mixed oxide. The proposed method does not require the complicated separation step of plutonium and uranium.

Analysis of flucytosine dosage forms by derivative UV spectroscopy and liquid chromatography

A simple second-order derivative spectrophotometric method was developed for the selective determination of flucytosine (an antimycotic drug) in the presence of 5-fluorouracil (a cytotoxic agent), its synthetic precursor and degradation product. Traces of 5-fluorouracil in flucytosine were also determined by derivative UV spectroscopy; flucytosine was removed by a selective solid-phase extraction (SPE) procedure using a strong cation-exchange sorbent. The spectrophotometric methods were applied successfully to the quality control of commercial dosage forms of flucytosine and the results were compared with those obtained by a HPLC procedure (cyano column) developed as a reference method.