Simple Spectrophotometric Method For Determination Research Articles

Development, Validation and Greenness Assessment of Three Simple Spectrophotometric Methods for Determination of Two Combined Broad-Spectrum Antibacterial Agents

Development, Validation and Greenness Assessment of Three Simple Spectrophotometric Methods for Determination of Two Combined Broad-Spectrum Antibacterial Agents

The Spectrophotometric Determination of Antiepileptic Drug in Standard and Pharmaceutical Formulations by Diazotization Coupling Reaction and Some Metals Complexes

A rapid, sensitive spectrophotometric method has been proposed for the determination of Gabapentin antiepileptic drug in pure and in pharmaceutical preparations was developed. The method is based on the coupling reaction between Gabapentin with8-hydroxy quinoline in to form an olive colored azo dye which gave maximum absorption at 365nm.The optimum reaction conditions like: pH, Temperature affected and time of reaction were evaluated. The ligand and its complexes were characterized by UV-visible spectroscopy, infrared FT-IR, (C.H.N.) analysis and Molar conductivity. The ratio of (metal: ligand) of all complexes was (1:2) by using molar ratio method and jop’s method. Beer’s law is obeyed for ligand and its complexes with (Cu2+, Ni2+,Cd2+, Co2+ and Zn2+) in concentration ranges ( 2 - 20, 1.5 - 25, 1 - 20, 2 - 25 and 2-30μg ml-) respectively . The molar absorptivity also calculated and it's found to be (1.396×104, 2.0208×104, 2.295×104, 1.684×104 and 1.862×104 L.mol-1.cm-1) for Cu2+, Ni2+,Cd2+, Co2+ and Zn2+complexes respectively. The detection of limit and quantification of limits are also calculated. The stability constant of complexes equal to(3.273×106, 1.695×102, 7.859×106, 1.851×105 and 1.588×102 L2.mol-2) for Cu2+, Ni2+,Cd2+, Co2+ and Zn2+ complexes respectively. The method is successfully used for the determination of Gabapentin in pharmaceutical formulations. Analytical parameters like accuracy and precision for the method have been established and evaluated statistically to assess the application of the proposed method. No interferes observed in the proposed method. The complexion with five ions (Cu2+, Ni2+, Cd2+, Co2+ and Zn2+) were studying. The aim of present work was devoted to investigate the reaction between Gabapentin and 8-hydroxy quinoline to form color Azo dye and use this product in the development of sensitive and simple spectrophotometric method for determination of Gabapentin in its pure and pharmaceutical preparations and spectrophotometric studies of a azo dye formed and it's metal complexes with Cu2+, Ni2+, Cd2+, Co2+ and Zn2+ ions.

A Simple Spectrophotometric Method for Determination of Glyoxylic Acid in Its Synthesis Mixture.

A new simple and reliable spectrophotometric method is described to determine glyoxylic acid in its synthesis reaction mixture containing oxalic acid, glycolic acid, acetic acid, glyoxal, and ethylene glycol by means of a modified Hopkins–Cole reaction between glyoxylic acid and tryptophan in presence of ferric chloride and concentrated sulphuric acid. The linear range of glyoxylic acid concentration is 0–0.028 M. The limits of detection (LOD) and quantitation (LOQ) are 0.0019 M and 0.00577 M, respectively. The LOD, LOQ, standard deviation, relative standard deviation, and recovery ratio of the proposed method are comparable with a selected HPLC reference method. Both methods displayed same precision and credibility. Reaction stoichiometry between tryptophan and glyoxylic acid is assumed to be 2 : 3. Reaction mechanism has been postulated based on identified molar ratios of reactants. Glyoxal gave a negative test with tryptophan although it is a dialdehyde.

Simple Spectrophotometric Method for Determination of Iron in Crude Oil

In this research article, spectrophotometric method for the determination of iron with 1,10-phenanthroline (phen) in two different crude oil samples from different oil fields in the Suez-Gulf region of Egypt has been proposed. The method is efficient, reliable and inexpensive where a cost-effective technique, along with commercially available spectrophotometric reagent, was utilized in this work. The method was based on decomposition of the organic matrix by combustion in a heating muffle furnace at 550°C. The inorganic residue was then dissolved in diluted nitric acid and the iron was reduced to the divalent state. The color was developed by the addition of 1,10-phenanthroline as chelating agent after adjusting the pH of the solution, then the absorbance of the solution was measured at approximately 510 nm after a short reaction period. The limit of detection (LOD) and limit of quantification (LOQ) obtained were found to be 0.017 and 0.051 μg/mL, respectively. The effect of interferences was studied and the accuracy of the method was evaluated by recovery experiment, analysis of oil reference material and by comparison of results with those obtained using flame atomic absorption spectrometer (FAAS) after dilution in an organic solvent for sample preparation.

Simple spectrophotometric methods for determination of fluoxetine and clomipramine hydrochlorides in dosage forms and in some post-mortem biological fluids samples

Sensitive, simple and rapid spectrophotometric methods for micro determination of fluoxetine hydrochloride (FLU) and clomipramine hydrochloride (CLO). The methods are based on the reaction between the examined drugs and acid dyes, namely; bromocresol green (BCG), phenol red (PhR) and metanil yellow (MY) producing yellow ion-pair complexes followed by their extraction with methylene chloride and measured at 412, 407 and 409nm for FLU with BCG, PhR and MY, respectively; whereas for CLO at 409, 406 and 407nm, respectively. All variables that affect the performance of the proposed methods were carefully studied and optimized. Beer’s law was obeyed in the concentration ranges 0.86–24.32μg/mL, 8.64–41.30μg/mL, 0.86–34.76μg/mL for FLU and 1.75–24.55μg/mL, 7.0–50μg/mL, 1.65–34.78μg/mL for CLO using BCG, PhR and MY respectively. The methods were validated in terms of accuracy and precision. The proposed methods were successfully applied to the determination of fluoxetine hydrochloride and clomipramine hydrochloride in pure samples, pharmaceutical formulations, spiked post-mortem urine and blood samples.

Spectrophotometric determination of hydrogen sulfide in environmental samples using sodium 1,2-naphthoquinone-4-sulfonate and response surface methodology

A simple spectrophotometric method for determination of hydrogen sulfide in wastewater and hot spring samples was developed. The method is based on the reaction between hydrogen sulfide and sodium 1,2-naphthoquinone-4-sulfonate (NQS). The effect of various experimental factors on the reaction between hydrogen sulfide and NQS was investigated and optimized using central composite design. The optimal values of the factors were 5.00 × 10−4 mol L−1 for concentration of NQS and 1.00 × 10−2 mol L−1 for concentration of hydrochloric acid. The wavelength of the maximum absorption of the reaction product was 320 nm. Constructed calibration curve for hydrogen sulfide determination was linear in the range of 0.5–20.0 mg L−1 with the detection limit of 0.16 mg L−1. The method was free from interferences. Percent relative errors below 2 % were obtained for determination of hydrogen sulfide in environmental samples.

A simple spectrophotometric method for determination of thiamine (vitamin B1) in pharmaceuticals

A simple spectrophotometric method has been described for the determination of thiamine. The method is based on the precipitation of sulphur as barium sulphate using barium chloride after oxidation of thiamine by sodium hydroxide and hydrogen peroxide. Beer's law was obeyed over the concentration range from 2-32 µg/mL thiamine. The average of standard deviation was 1.18×10 -2 ; standard error, 5.20×10 -3 ; relative standard deviation, 0.51%; relative standard error, 5.40×10 -3 ; 95% coefficient, 1.48×10 -2 ; the limit of detection, 0.41 µg/mL; the limit of quantification, 1.38 µg/mL and recovery, 100.03% thiamine. Finally, the developed method was applied to the determination of thiamine in pharmaceutical formulations.

Simple spectrophotometric method for determination of polyvinylalcohol in different types of wastewater

The determination of polyvinylalcohol (PVA) by the formation of the blue iodine–PVA complex method was established for a semi-micro method scale. The direct addition of iodine solution proved to be a better iodine source than iodine generated in situ. The ageing of reagents requires frequent calibrations. Common biopolymers such as starch, albumin and cellulose produced much lower colour intensity with reagents and their impact on the analysis is negligible. The method is not affected by paper filter filtration. The detection of PVA was successfully tested in different wastewater types and the method proved to be a powerful tool for PVA detection. It must be emphasised that quantification of PVA is strongly dependent on the PVA type and the quantification capacity; without information of the PVA structure or type is only tentative.

New simple spectrophotometric method for determination of the antiviral mixture of emtricitabine and tenofovir disoproxil fumarate

A new simple spectrophotometric method was recently developed for the determination of binary mixtures without prior separation. The method is based on generation of ratio spectra of compound X by using standard spectrum of compound Y as a divisor, then the peak to peak (or peak to trough) amplitudes between two selected wavelengths in the ratio spectra are found proportional to concentration of X without interference from compound Y. The method was applied for the determination of the antiviral mixture of emtricitabine (EMT) and tenofovir disoproxil fumarate (TEN). For the determination of EMT, a solution of 15μg/mL TEN was used as divisor to generate the ratio spectra, and the peak to trough amplitudes between 228.5 and 260.5nm were plotted against EMT concentration. Similarly by using 10μg/mL EMT as divisor, the peak to trough amplitudes between 229 and 260nm were found proportional to TEN concentration. The reliability and analytical performance of the proposed spectrophotometric procedure were statistically validated with respect to linearity, range, precision, accuracy, detection and quantification limits. Calibration curves were linear in the range of 2–40μg/mL for both drugs with correlation coefficients >0.9997. The proposed method was successfully applied for the simultaneous determination of the two drugs in several laboratory prepared mixtures and in their combined tablet dosage form.

Simple spectrophotometric method for determination of melamine in liquid milks based on green Mannich reaction

A new and simple spectrophotometric method has been developed and validated for measuring the contamination of melamine in different milk products. The method is based upon measuring the absorption of the complex formed from melamine, 4-hydroxyacetophenone (Hap) and 1-pyrene carboxaldehyde (Pcd), which was adapted from the Mannich reaction. Quantitative analysis was done at a wavelength of 236nm within a few minutes. The reaction was optimized by focusing on both obtaining high performance of the method and to concern the volatility and toxicity of used reagents. This method provided a linear dynamic range, limit of detection and limit of quantification of 0.100–3.78, 0.08 and 0.14mgL−1, respectively. The relative standard deviation (RSD) was 3.6% (n=10). The recoveries of melamine spiked liquid milk samples, with melamine concentrations of 0.63, 1.26, 1.89 and 2.52mgL−1, were 87.7±3.7%, 91.1±8.8%, 89.2±4.4% and 90.6±3.6% (n=3), respectively.

Simple Spectrophotometric Methods for Determination of Tenofovir Fumarate and Emtricitabine in Bulk Powder and in Tablets

Two simple and selective methods were developed for the simultaneous determination of tenofovir fumarate (TEN) and emtricitabine (EMT) in combined tablets. The first method involves the application of first derivative spectrophotometry where the first derivative amplitudes were measured at 298.5 nm for determination of EMT in presence of TEN. The second method involves first derivative of ratio spectra spectrophotometry where the amplitudes at 251.5 nm have been used for quantitation of TEN in the presence of EMT. Different variables affecting each method were carefully investigated and optimized. Reliability and analytical performance of the proposed methods, including linearity, range, precision, accuracy, detection, and quantitation limits, were statistically validated. The methods were successfully applied for the determination of EMT and TEN in laboratory-prepared mixtures and in their combined tablets.

SPECTROPHOTOMETRIC METHODS FOR THE DETERMINATION OF FAMOTIDINE IN DRUG FORMULATIONS.

This paper describes two sensitive and simple spectrophotometric methods for determination of famotidine in pharmaceutical preparations. The first method is based on the hydrolisis of famotidine with sodium hydroxide assisted with microwave radiation, whereby the sulfide ion is produced. The sulfide was allowed to react with N,N – diethyl – p – phenylendiamine oxalate and Fe(III), and the blue color produced was measured at 671 nm. Beer’s law was fulfilled in the concentration range 0.6 – 52.8 µg/mL, with a detection limit of 0.2 µg/mL. The second method is based upon the formation of a ternary complex between lead (II), eosin and famotidine in the presence of methyl cellulose as a surfactant. The ternary complex showed an absorption maximum at 541 nm. The method obeys Beer’s law over concentration range of 7.4-100.0 µg/mL. The methods are simple, sensitive and accurate. The proposed methods was applied on the famotidine determination in tablets and intravenous solution, shows recoveries in the range of 97.9-104.2 %. The results obtained by proposed methods were statistically validated.

Simple Method for Spectrophotometric Determination of Benzidine in Aqueous Solutions by Coupling with Β-Naphthol

Anew simple and rapid colorimetric method has been developed for the determination of benzidine in aqueous solutions. The method is based on the formation of a pink colored azo dye by diazotization of benzidine, followed by a diazo-coupling reaction between the resulting product and β-naphthol. The maximum absorbance of azo dye at 525 nm. Beer's law was found to be obeyed in the concentration range of 0 -12 µg . ml -1 with molar absorptivity 12360 L. mol -1 . cm -1 . The

A simple spectrophotometric method for determination of antimony( III) with N-bromosuccinimide and methyl orange

In this study, a simple and sensitive spectrophotometric method for the determination of antimony(III) is described. It is based on the oxidation of antimony(III) with slight excess of N-bromosuccinimide (NBS) in acidic medium and the unconsumed (NBS) is determined with methyl orange (λ max 500 nm). Beer's law is obeyed over the concentration range of 0.4―2.8 μg/ml for antimony(III). The molar absorptivity and Sandell's sensitivity were found to be 3.43 x 10 4 L mol ―1 cm ―1 and 0.0035 μg cm ―2 respectively. The method has been successfully applied for the determination of Sb III in water, soil and biological samples.

Simple Spectrophotometric Method for Determination of Paroxetine in Tablets Using 1,2‐Naphthoquinone‐4‐Sulphonate as a Chromogenic Reagent

Simple and rapid spectrophotometric method has been developed and validated for the determination of paroxetine (PRX) in tablets. The proposed method was based on nucleophilic substitution reaction of PRX with 1,2-naphthoquinone-4-sulphonate (NQS) in an alkaline medium to form an orange-colored product of maximum absorption peak (λ max) at 488 nm. The stoichiometry and kinetics of the reaction were studied, and the reaction mechanism was postulated. Under the optimized reaction conditions, Beer's law correlating the absorbance (A) with PRX concentration (C) was obeyed in the range of 1–8 μg mL−1. The regression equation for the calibration data was: A = 0.0031 + 0.1609 C, with good correlation coefficients (0.9992). The molar absorptivity (ε) was 5.9 × 105 L mol−1 1 cm−1. The limits of detection and quantitation were 0.3 and 0.8 μg mL−1, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the determination of PRX in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was 97.17 ± 1.06 %. The results obtained by the proposed method were comparable with those obtained by the official method.

A simple spectrophotometric method for determination of gold (III) in aqueous samples

A simple method for rapid determination of trace Au in natural water was presented by using UV–vis spectrophotometry after reaction of gold (III) with 3,3′, 5,5′-tetramethylbenzidine hydrochloride (TMBH) in acidic solution. Under the optimum conditions, in a concentration range of 100–2000 μg L −1 of Au (III) a good linear calibration graph was obtained ( r = 0.9969, n = 7). The percent relative standard deviation (RSD) for determination of 1000 μg L −1 Au was 10% ( n = 3) and limit of detection based on a signal-to-noise ratio (S/N) of 3 (3S bl) was 50 μg L −1. The proposed method has been successfully applied to the determination of gold spiked and real aqueous samples.

A new spectrophotometric determination of famotidine from tablets

A simple spectrophotometric method for determination of famotidine was described. The method was based on bromination of the drug with excess brominating mixture in acidic medium. The yellow colour developed was measured at 350 nm against distilled water blank. Beer's law was obeyed in the range of 40-200 µg/ml.

A simple spectrophotometric method for determination of sodium diclofenac in pharmaceutical formulations

A new, simple, rapid and accurate spectrophotometric method is proposed for determination of sodium diclofenac (SD) in pharmaceutical preparations based on its reaction with concentrated nitric acid (63% w/v). The reaction product is a yellowish compound with maximum absorbance at 380 nm. The corresponding calibration curve is linear over the range of 1–30 mg l −1, while the limit of detection is 0.46 mg l −1.

Development of a simple analytical methodology for determination of glucosamine release from modified release matrix tablets

A simple spectrophotometric method for determination of glucosamine release from sustained release (SR) hydrophilic matrix tablet based on reaction with ninhydrin is developed, optimized and validated. The purple color ( Ruhemann purple) resulted from the reaction was stabilized and measured at 570 nm. The method optimization was essential as many procedural parameters influenced the accuracy of determination including the ninhydrin concentration, reaction time, pH, reaction temperature, purple color stability period, and glucosamine/ninhydrin ratio. Glucosamine tablets (600 mg) with different hydrophilic polymers were formulated and manufactured on a rotary press. Dissolution studies were conducted (USP 26) using deionized water at 37 ± 0.2 °C with paddle rotation of 50 rpm, and samples were removed manually at appropriate time intervals. Under given optimized reaction conditions that appeared to be critical, glucosamine was quantitatively analyzed and the calibration curve in the range of 0.202–2.020 mg ( r = 0.9999) was constructed. The recovery rate of the developed method was 97.8–101.7% ( n = 6). Reproducible dissolution profiles were achieved from the dissolution studies performed on different glucosamine tablets. The developed method is easy to use, accurate and highly cost-effective for routine studies relative to HPLC and other techniques.

Spectrophotometric Determination of Acyclovir and Amantadine Hydrochloride through Metals Complexation1

A simple spectrophotometric method for determination of some antiviral drugs, such as acyclovir and amantadine hydrochloride in pure and dosage forms, have been developed. The proposed method is based on the reactions of the selected drugs and metals. Acyclovir was reacted with copper (II) and cobalt (II) using a borax/sodium pH 9 hydroxide buffer, and in a non-aqueous medium using 1% pyridine in methanol, respectively.The formed complexes were absorbed maximally at A, 290 nm and at X 287 nm. The method determined from 112–1620 μg/mL of acyclovir, with a mean percentage of recovery of 99.32 ± 0.63 and of 98.77 ± 0.70 for copper (II) and cobalt (III), respectively.The suggested method was applied to a Novirus capsule, and its validity was ascertained by the standard addition technique. In addition, amantadine hydrochloride was allowed to react with iron (III) at pH 3 adjusted with 0.1 M ammonium hydroxide. The formed complex absorbed maximally at λ 295 nm. This method determined from 94–940 μg/mL of amantadine hydrochloride with a mean percentage of recovery of 99.49 ± 0.57. The suggested method was applied to an Adamine capsule, and its validity was ascertained by the standard addition technique.