scholarly journals Determination of Histidine by Atomic Absorption Spectroscopy

1997 ◽  
Vol 80 (4) ◽  
pp. 741-745 ◽  
Author(s):  
Amina M El-Brashy ◽  
Sheikha M Al-Ghannam
Keyword(s):  
Thin Layer ◽  
Atomic Absorption ◽  
Standard Addition ◽  
Dosage Forms ◽  
Neutral Medium ◽  
Official Method ◽  
Regression Equations ◽  
Spectrophotometric Methods ◽  
Separation Results

Abstract Two atomic absorption spectrophotometric methods are described for determination of histidine. The first is based on reaction of histidine with mercury(II) ions in phosphate buffer (pH 9). The second is based on reaction of histidine with iron(III) ions in neutral medium. The precipitate formed in both methods is separated by centrifugation, and the equivalent Hg(II) or Fe(III) ions as well as surplus ions in the filtrate are determined by atomic absorption at 253.6 and 248.3 nm for Hg and Fe, respectively. Amounts of histidine are calculated from calibration graphs prepared by standard addition methods or by regression equations. The procedures were successfully applied to assay of histidine in dosage forms after thin-layer chromatographic separation. Results compared favorably with those of the official method.

Development and validation of kinetic and atomic absorption spectrophotometric methods for the determination of salbutamol sulfate

RSC Advances ◽  
2015 ◽  
Vol 5 (70) ◽  
pp. 57164-57170 ◽  
Author(s):  
R'afat Mahmoud Nejem ◽  
Mahmoud Mohamed Issa ◽  
Mozer Hosny AL-Kholy ◽  
Akila Amin Saleh ◽  
Alaa Abu Shanab ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Dosage Forms ◽  
Salbutamol Sulfate ◽  
Spectrophotometric Methods ◽  
Development And Validation

Two sensitive kinetic and atomic absorption spectrophotometric (AAS) methods were developed for the determination of salbutamol sulfate (SLS) in its dosage forms.

scholarly journals Spectrophotometric Methods for the Determination of Ceftiofur and Tulathromycin in Bulk and Dosage Forms

2020 ◽  
pp. 34-47
Author(s):  
Noha Salem Rashed ◽  
Amany Mohmed Abdelazeem ◽  
Fatma Ahmed Fouad
Keyword(s):  
Absorption Maximum ◽  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
Veterinary Drugs ◽  
Binary Complex ◽  
Eosin Y ◽  
Optimum Conditions ◽  
Spectrophotometric Methods

Two simple, accurate and precise spectrophotometric methods were developed for the determination of two veterinary drugs, ceftiofur and tulathromycin in pure form as well as in pharmaceutical formulations. The first one (Method A) based on the reducing action of ceftiofur on Fe (ΙΙΙ) to Fe (ΙΙ) in its complex with 1, 10- phenanthroline (ferrin complex) to give the orange-red colored ferroin complex that exhibits an absorption maximum at 511 nm. Ceftiofur exhibited good linearity in the concentration range of 0.3-3.0 μg mL−1.The second method (Method B) depended on formation of a binary complex between tulathromycin and eosin Y in in the presence of carboxy methylcellulose as surfactant. Under the optimum conditions, the binary complex showed absorption maxima at 556 nm. The method obeyed Beer’s law over concentration range of 1.0–15.0 μg mL−1.  The proposed methods were used for determination of the studied drugs in pharmaceutical formulation; maxfur® powder and draxxin® injections with mean recoveries of 99.57and 99.71%, respectively. The validity of the methods was further proved by applying the standard addition technique. A proposal of the reactions pathways were described.

scholarly journals Spectrophotometric determination of etamsylate in pharmaceuticals using ferric chloride based on complex formation reactions

2010 ◽  
Vol 16 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Vinay Basavaiah ◽  
Doddarevanna Revanasiddappa ◽  
Zenita Devi ◽  
Kanakapura Basavaiah
Keyword(s):  
Complex Formation ◽  
Ferric Chloride ◽  
Rapid Determination ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Neutral Medium ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Precision And Accuracy

The present study describes two simple and selective spectrophotometric methods for the rapid determination of etamsylate (ETM) in bulk and in capsule formulations. The methods are based on the oxidation of ETM with ferric chloride in neutral medium and subsequent chelation of the resulting iron(II) with 1,10-phenanthroline (Phen) (method A) and with 2,2?-bipyridyl (Bipy) (method B). The resulting red colored chromogens are measured at 510 and 520 nm, in method A and B, respectively. In both methods, the absorbance is found to increase linearly with increasing ETM concentration. Beer?s law is obeyed over the ranges 0.5-10 and 0.8-16 ?g/ml for method A and B, respectively. The calculated molar absorptivity values are 2.17?104 and 1.65?104 l/mol/cm for method A and B, respectively, and the corresponding sandell sensitivities are 0.012 and 0.016 ?g/cm2. Intra-day and inter-day precision and accuracy of the methods were established according to ICH guidelines. The proposed methods were applied to determine ETM in dosage forms and the results were statistically compared with that of an official BP method.

scholarly journals The development and validation of visible spectrophotometric methods for simvastatin determination in pure and the tablet dosage forms

2008 ◽  
Vol 14 (3) ◽  
pp. 205-210 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Kalsang Tharpa
Keyword(s):  
Acid Medium ◽  
Standard Addition ◽  
Dosage Forms ◽  
Spectrophotometric Methods ◽  
Red Color ◽  
Assay Precision ◽  
Development And Validation ◽  
Tablet Dosage

Two simple and sensitive spectrophotometric methods have been developed for the determination of simvastatin (SMT) in pure form and in tablets using insitu generated bromine, and p-phenylenediamine (PPDA) or o-dianisidine (ODA) as reagents. The methods are based on the bromination of SMT by a measured excess of in situ bromine in acid medium followed by the determination of unreacted bromine by reacting with PPDA and measuring the resulting red color at 510 nm (method A) or reacting with ODA and measuring the absorbance at 470 nm (method B). The conditions for the assay have been optimized. Beer's law is obeyed over the concentration ranges 20-120 and 2-12 ?g/ml for method A and method B, respectively. The calculated molar absorbtivities are 2.24?103 and 1.91?104 dm3 mol-1 cm-1 for the method A and the method B, respectively; 0.1868 and 0.0115 ?g/cm2 being the corresponding Sandell sensitivities. The LOD and LOQ for method A are found to be 2.96 and 8.97 ?g/ml, and the respective values for method B are 0.14 and 0.42 ?g/ml. The intra-day and inter-day precision and accuracies were checked. The assay precision was less than 5 % CV and the accuracy was 97.38-103.4 %. The methods were used for the determination of SMT in tablets. No interference from the excipients added to tablets was found. The accuracy and validity of the methods were further ascertained by recovery studies via the standard addition technique.

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

scholarly journals Application of Derivative, Derivative Ratio, and Multivariate Spectral Analysis and Thin-Layer Chomatography-Densitometry for Determination of a Ternary Mixture Containing Drotaverine Hydrochloride, Caffeine, and Paracetamol

2007 ◽  
Vol 90 (2) ◽  
pp. 391-404 ◽  
Author(s):  
Fadia H Metwally ◽  
Yasser S El-Saharty ◽  
Mohamed Refaat ◽  
Sonia Z El-Khateeb
Keyword(s):  
Thin Layer ◽  
Least Squares ◽  
Ternary Mixture ◽  
Principal Component Regression ◽  
Pharmaceutical Preparations ◽  
Principal Component ◽  
Standard Addition ◽  
Drotaverine Hydrochloride ◽  
Assay Precision

Abstract New selective, precise, and accurate methods are described for the determination of a ternary mixture containing drotaverine hydrochloride (I), caffeine (II), and paracetamol (III). The first method uses the first (D1) and third (D3) derivative spectrophotometry at 331 and 315 nm for the determination of (I) and (III), respectively, without interference from (II). The second method depends on the simultaneous use of the first derivative of the ratio spectra (DD1) with measurement at 312.4 nm for determination of (I) using the spectrum of 40 μg/mL (III) as a divisor or measurement at 286.4 and 304 nm after using the spectrum of 4 μg/mL (I) as a divisor for the determination of (II) and (III), respectively. In the third method, the predictive abilities of the classical least-squares, principal component regression, and partial least-squares were examined for the simultaneous determination of the ternary mixture. The last method depends on thin-layer chromatography-densitometry after separation of the mixture on silica gel plates using ethyl acetatechloroformmethanol (16 + 3 + 1, v/v/v) as the mobile phase. The spots were scanned at 281, 272, and 248 nm for the determination of (I), (II), and (III), respectively. Regression analysis showed good correlation in the selected ranges with excellent percentage recoveries. The chemical variables affecting the analytical performance of the methodology were studied and optimized. The methods showed no significant interferences from excipients. Intraday and interday assay precision and accuracy values were within regulatory limits. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of their pharmaceutical preparations. The validity of the proposed methods was further assessed by applying a standard addition technique. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

scholarly journals Cerimetric determination of simvastatin in pharmaceuticals based on redox and complex formation reactions

2018 ◽  
Vol 33 (2) ◽  
pp. 21
Author(s):  
Kanakapura Basavaiah ◽  
Okram Zenita Devi
Keyword(s):  
Limit Of Detection ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Fixed Quantity ◽  
Bulk Drug ◽  
Student’S T

Two sensitive spectrophotometric methods are described for the determination of simvastatin (SMT) in bulk drug and in tablets. The methods are based on the oxidation of SMT by a measured excess of cerium (IV) in acid medium followed by determination of unreacted oxidant by two different reaction schemes. In one procedure (method A), the residual cerium (IV) is reacted with a fixed concentration of ferroin and the increase in absorbance is measured at 510 nm. The second approach (method B) involves thereduction of the unreacted cerium (IV) with a fixed quantity of iron (II), and the resulting iron (III) is complexed with thiocyanate and the absorbance measured at 470 nm. In both methods, the amount of cerium (IV) reacted corresponds to SMT concentration. The experimental conditions for both methods were optimized. In method A, the absorbance is found to increase linearly with SMT concentration (r = 0.9995) whereas in method B, the same decreased (r = -0.9943). The systems obey Beer’s law for 0.6-7.5 and 0.5-5.0 μg mL-1 for method A and method B, respectively. The calculated molar absorptivity values are 2.7 X 104 and 1.06 X 105 Lmol-1 cm-1, respectively; and the corresponding sandel sensitivity values are 0.0153 and 0.0039μg cm-2, respectively. The limit of detection (LOD) and quantification (LOQ) are reported for both methods. Intra-day and inter-day precision, and accuracy of the methods were established as per the current ICH guidelines. The methods were successfully applied to the determination of SMT in tablets and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common excipients added to tablets. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard addition procedure.

scholarly journals SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF SOFOSBUVIR AND DACLATASVIR IN PURE AND DOSAGE FORMS

2021 ◽  
pp. 112-119
Author(s):  
MONIR Z. SAAD ◽  
ATEF AMER ◽  
KHALED ELGENDY ◽  
BASEM ELGENDY
Keyword(s):  
Indigo Carmine ◽  
Reference Method ◽  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Experimental Conditions ◽  
Fixed Amount ◽  
Alizarin Red ◽  
Spectrophotometric Methods

Objective: Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of sofosbuvir (SOF) and daclatasvir (DAC) in pure forms and pharmaceutical formulations. Methods: The proposed methods are based on the oxidation of SOF and DAC by a known excess of cerium(IV) ammonium nitrate in sulphuric acid medium followed by determination of unreacted cerium(IV) by adding a fixed amount of indigo carmine (IC) and alizarin red S (ARS) dyes followed by measuring the absorbance at 610 and 360 nm, respectively. The experimental conditions affecting the reaction were studied and optimized. Results: The beer’s law was obeyed in the concentration ranges of 0.2-3.0, 0.2-4.0 for SOF and 0.5-4.5 and 0.5-5.0 μg/ml for DAC using IC and ARS methods, respectively with a correlation coefficient ≥ 0.9991. The calculated molar absorptivity values are 2.354 × 104, 1.933 × 104 for SOF and 1.786 × 104 and 2.015 × 104 L/mol. cm for DAC using IC and ARS methods, respectively u. The limits of detection and quantification are also reported. Intra-day and inter-day precision and accuracy of the methods have been evaluated. Conclusion: The methods were successfully applied to the assay of SOF and DAC in tablets and the results were statistically compared with those of the reference method by applying Student’s t-test and F-test. No interference was observed from the common tablet excipients. The accuracy and reliability of the methods were further ascertained by performing recovery studies using the standard addition method.

scholarly journals Simultaneous spectrophotometric determination of drugs lacking peak maxima in their zero-order profiles by graphical or statistical representation of data

2018 ◽  
Vol 9 (3) ◽  
pp. 194-201
Author(s):  
Ragaa Magdy ◽  
Ahmed Hemdan ◽  
Nermine Victor Fares ◽  
Maha Farouk
Keyword(s):  
Graphical Representation ◽  
Reference Method ◽  
Zero Order ◽  
Regression Equations ◽  
Spectrophotometric Methods ◽  
Statistical Representation ◽  
Tablet Dosage ◽  
Direct Spectrophotometry ◽  
One Way Anova

Trandolapril has no sharp peak in its zero-order spectrum, therefore it is difficult to be measured by direct spectrophotometry. In this study, direct univariate spectrophotometric methods were developed and validated for determination of Trandolapril and Verapamil combination in pure and tablet dosage forms. The first method for measuring both Trandolapril and Verapamil is Absorbance Subtraction (AS), this method depends on the presence of iso-absorptive point in the zero-order curve at 217 nm. It has the advantage of measuring the concentration of both Trandolapril and Verapamil from unified regression equation at the iso-absorptive point. The second, third and fourth methods were applied on the first order spectra of the studied drugs. Second method is Derivative Subtraction (DS) for Trandolapril and Derivative subtraction followed by spectrum subtraction (DS-SS) for Verapamil. The third and fourth methods are constant value and concentration value methods. In the concentration value method, the concentration of the drugs is determined from the graphical representation without the use of regression equations. All the developed methods were validated as per International Conference on Harmonization guidelines and the results proved that the developed methods are simple, accurate, and selective. Moreover, a statistical comparison between the developed methods and a reference method was done. Also, One-way ANOVA statistical test was done between all the proposed spectrophoto-metric methods and results showed no significant differences.

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