scholarly journals A New Spectrophotometric Method for the Determination of Dithianon in Commercial Formulations and Its Residues in Foodstuffs

1999 ◽  
Vol 82 (6) ◽  
pp. 1298-1302 ◽  
Author(s):  
Balbir C Verma ◽  
Hari K Thakur ◽  
Jasvir Singh ◽  
Devender K Sharma

Abstract A new, simple, and rapid spectrophotometric method for the microdetermination of dithianon, on the basis of its reaction with a dithiocarbamate, is described. The red color, which develops instantaneously when mixing the fungicide with the reagent in acetonitrile, is stable for at least 1 h and is measured at 520 nm. Beer's law is applicable up to 12 μg/mL dithianon concentration. The method has been successfully adapted to the analysis of the fungicide in commercial formulations and its residues on grains and apple (fruit and leaves). A photometric titration method for formulation analysis of the fungicide has also been developed.

1990 ◽  
Vol 38 (1) ◽  
pp. 87-94 ◽  
Author(s):  
M W Wessendorf ◽  
S J Tallaksen-Greene ◽  
R M Wohlhueter

7-Amino-4-methylcoumarin-3-acetic acid (AMCA) has been found to be a useful fluorophore for immunofluorescence. The present study describes a spectrophotometric method for determining the ratio of moles AMCA to moles protein (or the f/p ratio) in an AMCA-conjugated IgG. The concentration of a substance absorbing light can be determined spectrophotometrically using Beer's Law: Absorbance = Concentration x Extinction coefficient. From Beer's law, one can derive the following formula for determining the f/p ratio of AMCA-IgG conjugates: f/p = (epsilon 280IgG).A350 - (epsilon 350IgG).A280/(epsilon 350AMCA).A280 - (epsilon 280AMCA).A350 where A is the optical density of the conjugate at the given wavelength and epsilon is the extinction coefficient of a substance at the wavelength specified. Using conjugates of model proteins, it was found that the extinction coefficients of the AMCA moiety of AMCA-conjugated protein were 1.90 x 10(4) at 350 nm and 8.29 x 10(3) at 280 nm. Similarly, it was found that the extinction coefficients of swine IgG were 1.56 x 10(3) at 350 nm and 1.26 x 10(5) at 280 nm. Thus, for AMCA-conjugated swine IgG: f/p = (1.26 x 10(5)).A350 - (1.56 x 10(3)).A280/(1.47 x 10(4)).A280 - (6.42 x 10(3)).A350 [corrected]. Based on this formula, the f/p ratios of some AMCA-IgG conjugates useful for immunohistochemistry have been found to range between 6 and 24.


2007 ◽  
Vol 4 (1) ◽  
pp. 50-52 ◽  
Author(s):  
M. Vamsi Krishna ◽  
P. V. Madhavi Latha ◽  
D. Gowri Sankar

A simple, sensitive spectrophotometric method for the determination of Famciclovir and Racecodotril is developed. It is based on the formation of a colored oxidative coupling product between 2,6-dichloroquinone-chlorimide and the drug is described. The method has been extended to pharmaceutical preparations. The absorption maxima and Beer’s law limits for Famciclovir are 500 nm, 20-100 µg/mL and for Racecodotril are 460 nm, 12.5-62.5 µg/mL.


1982 ◽  
Vol 65 (1) ◽  
pp. 141-143
Author(s):  
Madiha B Sidhom ◽  
Michel E El-Kommos

Abstract A spectrophotometric method is described for the determination of menadione and menadione sodium bisulfite in bulk and in solution for injection. The method measures the intensity of the violet color (λmax 540 nm) developed when menadione reacts with thiosemicarbazide in alkaline medium. Beer's law is obeyed in the concentration range 4-40 μg/m L (r = 0.9995). The method is simple, sensitive, and particularly suited for routine analysis of official menadione sodium bisulfite injection. Results are comparable with the USP method.


2015 ◽  
Vol 12 (2) ◽  
pp. 317-323
Author(s):  
Baghdad Science Journal

A simple, and rapid spectrophotometric method for the estimation of paracetamol has been developed. The methods is based on diazotisation of 2,4-dichloroaniline followed by a coupling reaction with paracetamol in sodium hydroxide medium. All variables affecting the reaction conditions were carefully studied. Beer's law is obeyed in the concentration range of 4-350 ?gml?1 at 490 nm .The method is successfully employed for the determination of paracetamol in pharmaceutical preparations. No interferes observed in the proposed method. Analytical parameters such as accuracy and precision have been established for the method and evaluated statistically to assess the application of the method.


Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan

A spectrophotometric method has been developed for the determination of Fe(III) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into ethyl acetate at pH 6. The method obeys Beer’s law over arrange from 1 to 7 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.31 × 104 L mol-1cm-1 and 0.13 μg cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ramesh Kataria ◽  
Harish Kumar Sharma

An extractive spectrophotometric method for the determination of the trace amounts of tin has been carried out by employing 6-chloro-3-hydroxy-2-(2′-thienyl)-4-oxo-4H-1-benzopyran (in acetone) (CHTB) for the complexation of the metal ion in HCl medium. The colored species thus produced is quantitatively extracted into dichloromethane and shows the maximum absorbance at 432–437 nm. The method obeys Beer’s law in the range 0.0–1.3 μg mL−1 of tin with molar absorptivity and Sandell’s sensitivity of 5.81×104 L mol−1 cm−1 and 0.0020 μg Sn cm−2, respectively, at 435 nm. The method is highly selective and free from the interference of a large number of elements including platinum metals. The ratio of metal to ligand in the extracted species is 1 : 2. Utilizing this method, the analysis of various synthetic and technical samples including gun metal and tin can have been carried out satisfactorily.


2004 ◽  
Vol 87 (4) ◽  
pp. 811-814 ◽  
Author(s):  
Balbir C Verma ◽  
Sumita Sood ◽  
Chetan Chauhan ◽  
Devender K Sharma

Abstract A new, simple, rapid, and sensitive spectrophotometric method for the determination of thiophanate-methyl, based on its reaction with cobalt(II) in the presence of triethylamine, has been developed. The yellowish green color that develops instantaneously on mixing the fungicide with the reagents in dimethylformamide is stable for at least 2 h and has maximum absorbance at 360 nm. The method has been successfully applied to the determination of thiophanate-methyl in its commercial formulations and residues on grains and apples. A photometric titration procedure for formulation analysis of the fungicide has also been developed.


2020 ◽  
Vol 13 (3) ◽  
pp. 210-217
Author(s):  
Naveen Reddy Pailla ◽  
Bhaskar Kuthati

For the determination of three drugs namely Cilnidipine (CDP), Efavirenz (EVZ), Prazosin (PRZ), a simple, fast, selective and accurate spectrophotometric method has been outlined. This method is based on the development of blue coloured chromogen due to reduction of tungstate and/ or molybdate in Folin-Ciocalteu reagent by Drug in alkaline medium. The coloured species has an absorption maximum at 730 nm, 745 nm and 770 nm and the Beer’s law obeys over the concentration range of 12-72 μg/mL, 10-70 μg/mL, 3-21 μg/mL respectively for the drugs CDP, EVZ, PRZ. This method has been validated according to ICH guidelines and applied to the analysis of pharmaceuticals.


Author(s):  
Amir Alhaj Sakur ◽  
Shaza Affas

Objective: To develop and validate simple, sensitive, precise and free of organic solvents method for the determination of sildenafil (SIL) and vardenafil (VAR) in bulk and pharmaceutical formulation.Methods: The method is based on the reaction of studied drugs with a mixture of potassium iodide and potassium iodate in an aqueous medium at (25±2 °C) to form yellow coloured triiodide ions (I3-) within 45 min. The reaction is followed spectrophotometrically by measuring the absorbance at 288, 351 nm and 285, 351 nm for sildenafil and vardenafil respectively.Results: The effects of analytical parameters on the reported systems were investigated. Beer's law of SIL was obeyed in the range of (0.4-12) μg ml-1and (0.6-16) μg ml-1. Molar absorptivity was found to be (67.659 ×103) lmol/cmand (37.955×103) lmol/cm at 288 nm, 351 nm respectively. Beer's law of VAR was obeyed in the range of (0.2-13) μg/mland (0.5-40) μg/ml. Moreover, molar absorptivity’s were found to be (68.719 ×103) l mol-1 cm-1and (26.691×103) l mol-1 cm-1 at 285 nm, 351 nm respectively.Conclusion: The proposed method has been applied to determine the components in dosage forms with an average recovery of 98.15% to 103.45% and the results have been found in good agreement with those results obtained by the reference methods.


1989 ◽  
Vol 72 (6) ◽  
pp. 885-889 ◽  
Author(s):  
Abdel-Maboud I Mohamed

Abstract A new spectrophotometric method for the determination of some unsubstituted benzene sulfonamides is presented. The method is based on the interaction of these derivatives with 7,7,8,8-tetracyanoquinodimethane at pH 9.0-9.5 to produce intense blue products. The quantitation of the products was carried out at 578 nm. Beer’s law was obeyed over a wide range of concentrations for all sulfonamide compounds studied. Optimum analytical conditions were determined, and the color produced was stable for at least 90 min at 25 °C. Analytical data for determination of sulfonamide compounds in pure form are presented together with application of the proposed method for analysis of some commercially available pharmaceutical preparations. The results are in good agreement with those obtained by official procedures.


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