THE DETERMINATION OF PHOSPHOLIPID PHOSPHORUS

1949 ◽  
Vol 27e (3) ◽  
pp. 159-163 ◽  
Author(s):  
J. M. R. Beveridge ◽  
S. E. Johnson
Keyword(s):  
Color Stability ◽  
Accurate Method ◽  
Inorganic Phosphorus ◽  
Strict Adherence ◽  
Beer's Law ◽  
Beer’S Law ◽  
Excellent Color ◽  
Colorimetric Procedure

A simple accurate method for the determination of phospholipid phosphorus is described. Conditions for the digestion of phospholipid have been developed permitting the utilization of a colorimetric procedure for inorganic phosphorus that is characterized by excellent color stability and strict adherence to Beer's law over a range of 0 to 65 μgm. of phosphorus.

scholarly journals Spectrophotometric Determination of Aciclovir, Cefepirne Hydrochloride, Etamsylate and Metoclopramide Hydrochloride Usina 1,10 Phenanttrroline—Fe(lll) Reaqent

2004 ◽  
Vol 72 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Marwa S. Elazazy ◽  
Abdalla Shalaby ◽  
M. N. Elbolkiny ◽  
Hawa M. Khalil
Keyword(s):  
Spectrophotometric Determination ◽  
Pharmaceutical Formulations ◽  
Accurate Method ◽  
Pure Form ◽  
Reagent Blank ◽  
Experimental Conditions ◽  
Beer's Law ◽  
Beer’S Law ◽  
Metoclopramide Hydrochloride

A simple, rapid, sensitive and accurate method for the determination of aciclovir, cefepime HCI, etamsylate and metoclopramide HCI in pure form and in pharmaceutical formulations is developed.The method is based on the fomabon of tris(o-phenanthroline) iron(ll) complex (Ferroin) upon the reaction of the ated drugs wrth iron(lll )-o- phenanthroline mixture. The ferroin complex is colorimetncally measured at λmax 510 nm against a reagent blank. 0ptimization of the experimental conditions is described. Beer's law is obeyed in the concentration range from 0.25–30 µg ml−1 with molar absorpitivities (ε) ranging from 4.796 x 103–9.51 2 x 104 L.mol−1.cm−1 and Sandell sensitivities (S) of 2.129 x 10−3–34.5 x 10−3 µg cm−2. The developed method is applied successfully for the determination of the cited drugs in pure forms and in the corresponding pharmaceutical formulations without any interferences from common excipients.

scholarly journals A spectrophotometric method for determination of fluorophore-to-protein ratios in conjugates of the blue fluorophore 7-amino-4-methylcoumarin-3-acetic acid (AMCA)

1990 ◽  
Vol 38 (1) ◽  
pp. 87-94 ◽  
Author(s):  
M W Wessendorf ◽  
S J Tallaksen-Greene ◽  
R M Wohlhueter
Keyword(s):  
Acetic Acid ◽  
Optical Density ◽  
Extinction Coefficient ◽  
Spectrophotometric Method ◽  
Extinction Coefficients ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Given

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.

scholarly journals Rapid Spectrophotometric Determination of Phenoxazine

2010 ◽  
Vol 7 (2) ◽  
pp. 1001-1005
Author(s):  
Baghdad Science Journal
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Acidic Medium ◽  
Absorption Maximum ◽  
Aqueous Samples ◽  
Economic Method ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Stability

A rapid high sensitive and inexpensive economic method has been developed for the Determination of phenoxazine by using molecular spectrophotometry. The method is based on the oxidation of phenoxazine by potassium (meta)periodate in acidic medium. The oxidation conditions were selected to enhance the sensitivity and the stability of the pink colored species which shows an absorption maximum at 530 nm. The Beer’s law was obeyed for phenoxazine concentration range from 1 to 6 µg mL-1 with 0.003 µg mL-1 detection limit and provided variation coefficients between 0.4 to 1.7 %. This method was successfully applied for the determination of phenoxazine in aqueous samples

A Rapid Method for the Determination of Manganese Ethylenebisdithiocarbamate and its Residues on Grains

1975 ◽  
Vol 58 (6) ◽  
pp. 1232-1234
Author(s):  
Jois R Rangaswamy ◽  
Yadathore N Vijayashankar
Keyword(s):  
Rapid Method ◽  
Active Ingredient ◽  
Residue Analysis ◽  
Periodate Oxidation ◽  
Zinc Ion ◽  
Beer's Law ◽  
Beer’S Law ◽  
Permanganic Acid ◽  
The Relationship

Abstract A method has been developed, based on the periodate oxidation of the manganese in the coordination product of zinc ion and manganese ethylene bisdithiocarbamate to permanganic acid, to determine DithaneM-45. The relationship between the intensity of color and the concentration of manganese obeys Beer’s law up to 100 μg at 540 nm. The method can be easily applied to the determination of the active ingredient in formulations and also for residue analysis. The method is sensitive to 0.6 μg and can be used to determine 6 /xg fungicide at the 20 g sample level.

scholarly journals Determination of Two Antibacterial Binary Mixtures by Chemometrics-Assisted Spectrophotometry

2007 ◽  
Vol 90 (1) ◽  
pp. 128-141 ◽  
Author(s):  
Abd El-Maaboud I Mohamed ◽  
Osama H Abdelmageed ◽  
Ibrahim H Refaat
Keyword(s):  
Binary Mixtures ◽  
Colorimetric Method ◽  
Correlation Coefficients ◽  
Dosage Forms ◽  
Considerable Degree ◽  
Zero Crossing ◽  
First Derivative ◽  
Beer's Law ◽  
Beer’S Law

Abstract Simple chemometrics-assisted spectrophotometric methods are described for determination of 2 antibacterial binary mixtures. The mixtures are composed of norfloxacin in combination with tinidazole and erythromycin (as ethylsuccinate ester or stearate salt) in combination with trimethoprim. The normal UV absorption spectra of each pair of drugs in the studied mixtures, in the range of 200-400 nm, showed a considerable degree of spectral overlapping: 77.5% for the norfloxacintinidazole mixture and 84.3% for the erythromycintrimethoprim mixture. Resolution of the norfloxacintinidazole mixture and trimethoprim in the presence of erythromycin was accomplished successfully by using zero-crossing first derivative (1D), classical least-squares (CLS) regression analysis, and principal component regression (PCR) analysis methods. In addition, an alternative simple and accurate colorimetric method was developed for the determination of erythromycin in the presence of trimethoprim using 2,4-dinitrophenylhydrazine. All variables affecting the development of the colored chromogen were studied and optimized, and the product was measured at 526-529 and 538-542 nm for erythromycin stearate and erythromycin ethylsuccinate, respectively. For zero-crossing, first derivative technique Beer’s law was obeyed in the general concentration range of 250 μg/mL for norfloxacin, tinidazole, and trimethoprim with good correlation coefficients (0.9994-0.9996). Overall limits of detection (LOD) and quantification (LOQ) ranged from 0.59 to 2.81 and 1.96 to 9.33 μg/mL, respectively. The obtained results from CLS and PCR were compared with those obtained from a 1D spectrophotometric method. With the exception of erythromycin, overall recoveries in the average range of 97.33-103.0% were obtained with a considerable degree of accuracy when the suggested methods were applied to analysis of synthetic binary mixtures, some commercial dosage forms such as tablets and oral suspension without interference from the commonly encountered excipients and additives. For the colorimetric method, Beer's law was obeyed in the general concentration range of 7.21-28.84 μg/mL erythromycin with good correlation coefficients (0.9980-0.9996). Overall LOD and LOQ ranged from 0.73 to 1.65 and 2.43-5.49 μg/mL, respectively. Erythromycin derivatives were determined in the commercial dosage form, without interference from trimethoprim-encountered excipients and additives. The obtained results, with both chemometric and colorimetric methods, have been compared with those obtained from reported methods, and proper F- and t-values were observed, indicating no significant difference between the results of the suggested methods and reported method(s). The good percentage recoveries and proper statistical data obtained proved the efficiency of the proposed procedures for the determination of the studied drugs in their binary mixtures as well as in the commercial dosage forms with quite satisfactory precision.

Spectrophotometric Determination of Pyridoxine Hydrochlorine in Pharmaceutical Preparations and Foods

1997 ◽  
Vol 80 (6) ◽  
pp. 1368-1373 ◽  
Author(s):  
Kailasam Srtvidya ◽  
Natesan Balasubramanian
Keyword(s):  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Spectrophotometric Assay ◽  
Stable Complex ◽  
Pyridoxine Hydrochloride ◽  
Beer's Law ◽  
Rice Samples ◽  
Beer’S Law ◽  
Aqueous Volume

Abstract An easy and sensitive spectrophotometric assay of pyridoxine is described. The procedure is based on formation of an azo dye by the reaction of pyridoxine with diazotized 2,4-dinitroaniline followed by the reaction of the dye with Hg2+ ions to form a stable complex with maximum absorbance at 545 nm. The system obeys Beer’s law for 4–75 μg pyridoxine hydrochloride in an overall aqueous volume of 25 mL (correlation coefficient, 0.9998). On extraction into 5 mL butan-1-ol, the system obeys Beer’s law in the range 0.8–15 μg pyridoxine hydrochloride at 545 nm. The color is stable for 60 min in both aqueous and organic phases (molar absorptivity, 3.7 × 104 L/mol · cm; coefficient of variation, 3.1%, n = 10). The pyridoxine contents of pharmaceutical preparations, a processed foodstuff, and 2 rice samples were determined by using the proposed method. Assay reliability was established by recovery studies and parallel determination using a reported method.

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
Keyword(s):  
Spectrophotometric Method ◽  
Apple Fruit ◽  
Titration Method ◽  
Red Color ◽  
Beer's Law ◽  
Photometric Titration ◽  
Beer’S Law ◽  
Formulation Analysis

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.

scholarly journals Spectrophotometric Determination of Ziram in a Commercial Sample and Wheat by Extraction of Its Copper Dimethyldithiocarbamate Complex into Molten Naphthalene

2002 ◽  
Vol 85 (1) ◽  
pp. 146-148
Author(s):  
Ashok Kumar Malik ◽  
Avasarla L J Rao
Keyword(s):  
Spectrophotometric Determination ◽  
Final Solution ◽  
Wheat Grain ◽  
Reagent Blank ◽  
Commercial Sample ◽  
Dithiocarbamate Complex ◽  
Beer's Law ◽  
Beer’S Law

Abstract A method was developed for the determination of zinc(II) dimethyldithiocarbamate by converting it into the copper(II) dithiocarbamate complex, which is then extracted into molten naphthalene. The absorbance is measured at 430 nm versus a reagent blank. Beer's law is obeyed for concentrations of 0.63 × 10−3 to 17.2 × 10−3 g/L in the final solution. The method is sensitive and was applied to the determination of ziram in a commercial sample and in wheat grain.

scholarly journals Spectrophotometric Stability-Indicating Methods for the Determination of Leflunomide in the Presence of Its Degradates

2006 ◽  
Vol 89 (6) ◽  
pp. 1524-1531 ◽  
Author(s):  
Samah S Abbas ◽  
Lories I Bebawy ◽  
Laila A Fattah ◽  
Heba H Refaat
Keyword(s):  
Dosage Forms ◽  
Derivative Spectrophotometry ◽  
Reaction Conditions ◽  
Pharmaceutical Dosage Forms ◽  
First Derivative ◽  
Beer's Law ◽  
First Derivative Spectrophotometry ◽  
Colored Product ◽  
Beer’S Law

Abstract Five simple and sensitive methods were developed for the determination of leflunomide (I) in the presence of its degradates 4-trifluoromethyl aniline (II) and 3-methyl-4-carboxy isoxazole (III). Method A was based on differential derivative spectrophotometry by measuring the △1D value at 279.5 nm. Beer's law was obeyed in the concentration range of 2.0020.00 μg/mL with mean percentage accuracy of 100.07 1.32. Method B depended on first-derivative spectrophotometry and measuring the amplitude at 253.4 nm. Beer's law was obeyed in the concentration range of 2.0016.00 μg/mL with mean percentage accuracy of 98.42 1.61. Method C was based on the reaction of degradate (II) with 2,6-dichloroquinone-4-chloroimide (Gibbs reagent). The colored product was measured at 469 nm. Method D depended on the reaction of degradate (II) with para-dimethyl aminocinnamaldehyde (p-DAC). The absorbance of the colored product was measured at 533.4 nm. Method E utilized 3-methyl-2-benzothiazolinone hydrazone in the presence of cerric ammonium sulfate with degradate (II). The green colored product was measured at 605.5 nm. The linearity range was 40.00-280.00, 2.40-24.00, and 30-250 μg/mL with mean percentage accuracy of 100.75 1.21, 100.13 1.45, and 99.74 1.39 for Methods CE, respectively. All variables were studied to optimize the reaction conditions. The proposed methods have been successfully applied to the analysis of leflunomide in pharmaceutical dosage forms and the results were statistically compared with that previously reported.

Colorimetric Determination of Sympathomimetic Amines Methyldopa and Noradrenaline

1985 ◽  
Vol 68 (1) ◽  
pp. 91-95
Author(s):  
Mohamed I Walash ◽  
Abed Abou Ouf ◽  
Fatma B Salem
Keyword(s):  
Alkaline Solution ◽  
Dosage Forms ◽  
Colorimetric Determination ◽  
Sympathomimetic Amines ◽  
Chromogenic Reagent ◽  
Beer's Law ◽  
Beer’S Law ◽  
Orange Color

Abstract The chromogenic reagent p-dimethylaminocinnamaldehyde (PDAC) is introduced for the determination of the sympathomimetic amines methyldopa and noradrenaline. The method is based on measurement of the orange color developed when the alkaline solution of methyldopa and noradrenaline is allowed to react with PDAC at pH 5.0. The color developed obeys Beer's law in the concentration range 0.1-1.5 mL of 2 x 103M solution of noradrenaline and methyldopa. The results are compared with those obtained with another chromogenic reagent, pdimethylaminobenzaldehyde (PDAB). Determinations on dosage forms of the drugs, using PDAC and PDAB reagents, agreed well with results of determinations by official pharmacopoeia! methods.

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