Colorimetric Determination of C-2 Unsubstituted Phenothiazines, Using Morpholine and N-Bromosuccinimide

1986 ◽  
Vol 69 (5) ◽  
pp. 821-824 ◽  
Author(s):  
Salwa R El-Shabouri ◽  
Adel F Youssef ◽  
Fardous A Mohamed ◽  
Abdel Maboud I Rageh
Keyword(s):  
Analytical Data ◽  
Colorimetric Method ◽  
Pharmaceutical Preparations ◽  
Colorimetric Determination ◽  
Blue Color ◽  
Decomposition Products ◽  
Wide Range ◽  
Intact Drug ◽  
Pure Compounds

Abstract A colorimetric method for quantitative determination of 6 C-2 unsubstituted phenothiazine derivatives is described. The method is based on reaction of phenothiazine derivative with morpholine and N-bromosuccinimide reagents in aqueous methanol at 60°C to produce a blue color. Beer's law is obeyed in a wide range of concentrations for all 6 compounds at 660 nm. Optimum analytical conditions were determined and the produced color is stable for at least 24 h. Analytical data for determination of the pure compounds are presented together with the application of the proposed method to analysis of some pharmaceutical preparations. The results compare favorably with those of official methods. Furthermore, the method is specific for intact drug in the presence of oxidative decomposition products. The reaction product has been isolated and identified and a possible reaction mechanism is suggested.

Colorimetric Determination of Tetracycline Derivatives in Pharmaceutical Preparations

1989 ◽  
Vol 72 (2) ◽  
pp. 242-244 ◽  
Author(s):  
Utpal Saha
Keyword(s):  
Alkaline Medium ◽  
Copper Complexes ◽  
Colorimetric Method ◽  
Pharmaceutical Preparations ◽  
Cupric Chloride ◽  
Colorimetric Determination ◽  
Color Intensity ◽  
Yellowish Green ◽  
Maximum Absorbance

Abstract A quick colorimetric method is reported for the determination of tetracycline derivatives such as oxytetracycline hydrochloride (OTCH), chlortetracycline hydrochloride (CTCH), methacycline hydrochloride (MCH), and doxycycline hydrochloride (DCH). The method involves complexation of the above derivatives with cupric chloride in alkaline medium. The yellowish green copper complexes of OTCH, CTCH, MCH, and DCH show maximum absorbance at 395, 410, 400, and 400 nm, respectively. The color intensity obeys Beer's law in the concentration range of 0-20 μg/mL.

Colorimetric Determination of Diazepam in Pharmaceutical Preparations

1975 ◽  
Vol 58 (5) ◽  
pp. 875-878 ◽  
Author(s):  
Tulsidas R Baggi ◽  
Surinder N Mahajan ◽  
Griddaluru Ramana Rao
Keyword(s):  
Colorimetric Method ◽  
Pharmaceutical Preparations ◽  
Colorimetric Determination ◽  
Pyridoxine Hydrochloride ◽  
Yellow Solution ◽  
Beer's Law ◽  
Beer’S Law ◽  
Pure Drug ◽  
Solvent Blank

Abstract A colorimetric method is presented for the estimation of diazepam as the pure drug and in formulations. Diazepam is hydrolyzcd with 6N HC1 to 2-methyIamino-5-chlorobenzophenone, which is extracted with chloroform to give a yellow solution whose absorbance is measured at 410 nm against a solvent blank. The color obeys Beer's law in the concentration range of 0–30 μg/ml. In 5 determinations, recovery was 99.0±1.9%. The method is applicable to pure diazepam and its formulations for oral and parenteral use. No interferences were observed from pyridoxine hydrochloride and commonly used preservatives, vehicles, and colors.

Colorimetric Determination of Tetracycline Hydrochloride in Pharmaceutical Preparations

1987 ◽  
Vol 70 (4) ◽  
pp. 686-688 ◽  
Author(s):  
Utpal Saha
Keyword(s):  
Copper Complexes ◽  
Colorimetric Method ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Tetracycline Hydrochloride ◽  
Colorimetric Determination ◽  
Reagent Blank ◽  
Yellowish Green ◽  
Green Solution

Abstract A simple, sensitive, and rapid colorimetric method is presented for the estimation of tetracycline hydrochloride as the pure drug and in formulations. The proposed method is based on the reaction of tetracycline HC1 with cupric chloride in an alkaline medium to give a yellowish green solution whose absorbance is measured at 400 nm against a reagent blank. The color obeys Beer's law in the concentration range of 0-20 μg/mL. Molar absorptivity and Sandell's sensitivity of the yellowish-green copper complexes of tetracycline HC1 are 1.99 x 104 Lmol-1 cm-1 and 0.0241 ppm, respectively.

Spectrophotometric Determination of Some Benzene Sulfonamides with 7,7,8,8-Tetracyanoquinodimethane

1989 ◽  
Vol 72 (6) ◽  
pp. 885-889 ◽  
Author(s):  
Abdel-Maboud I Mohamed
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Analytical Data ◽  
Pharmaceutical Preparations ◽  
Pure Form ◽  
Wide Range ◽  
Beer's Law ◽  
Beer’S Law ◽  
Good Agreement

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.

Colorimetric Determination of Amoxicillin in Pure and some Pharmaceutical Formulations Via Reaction with Potassium Permanganate as Oxidant Reagent

2019 ◽  
Vol 10 (02) ◽  
Author(s):  
Abbas Shebeeb Al-kadumi ◽  
Sahar Rihan Fadhel ◽  
Mohammed Abdullah Ahmed ◽  
Luma Amer Musa
Keyword(s):  
Potassium Permanganate ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Atomic Emission ◽  
Basic Medium ◽  
Photometric Method ◽  
Colorimetric Determination ◽  
Spectrophotometric Methods ◽  
Label Claim

We proposed two simple, rapid, and convenient spectrophotometric methods are described for the determination of Amoxicillin in bulk and its pharmaceutical preparations. They are based on the measurement of the flame atomic emission of potassium ion (in first method) and colorimetric determination of the green colored solution for manganite ion at 610 nm formed after reaction of Amoxicillin with potassium permanganate as oxidant agent (in the second method) in basic medium. The working conditions of the methods were investigated and optimized. Beer's law plot showed a good correlation in the concentration range of 5-45 μg/ml. The detection limits and relative standared deviations were (2.573, 2.814 μg/ml) (2.137, 2.498) for the flame emission photometric method and (1.844, 2.016 μg/ml) (1.645,1.932) for colorimetric methods for capsules and suspensions respectively. The methods were successfully applied to the determination of Amoxicillin in capsules and suspensions, and the obtained results were in good agreement with the label claim. No interference was observed from the commonly encountered additives and expectancies.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

200. The colorimetric determination of pH in milk and whey by means of the “Wulff” pH tester

1938 ◽  
Vol 9 (3) ◽  
pp. 336-338 ◽  
Author(s):  
E. Aschaffenburg
Keyword(s):  
Colorimetric Method ◽  
Cheddar Cheese ◽  
Titratable Acidity ◽  
Colorimetric Determination ◽  
Expensive Equipment ◽  
Hydrogenion Concentration ◽  
The Relationship

It has been repeatedly pointed out(1, 2, 3) that the properties of cheese during the different stages of its manufacture should be correlated with the hydrogenion concentration rather than with the titratable acidity. Little systematic work has, however, so far been carried out in this direction, except for a study of the relationship between pH and titratable acidity in Cheddar cheese by Brown & Price(4). In planning work on similar lines, it was realized that the potentiometric methods of determining pH require expensive equipment and skilled attention, so that a supplementary colorimetric method, if sufficiently accurate to indicate the major changes in pH, should appeal more strongly to the practical cheesemaker on account of its cheapness and simplicity and the ease with which the outfit can be transported.

Determination of Bendiocarb Insecticide by Reverse Flow Injection Analysis Using a Solid-Phase Reactor Containing Micro PbO2, Nano PbO2 and Grafted SiO2 - PbO2 Immobilized

2020 ◽  
Vol 42 (1) ◽  
pp. 31-31
Author(s):  
Malik H Alaloosh Alamri Malik H Alaloosh Alamri ◽  
Sadeem Subhi Abed and Abdulkareem M A Alsammarraie Sadeem Subhi Abed and Abdulkareem M A Alsammarraie
Keyword(s):  
Flow Injection ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Reverse Flow ◽  
Blue Color ◽  
Wide Range ◽  
Solid Phase Reactor ◽  
Grafted Nanoparticles ◽  
Reverse Flow Injection

Bendiocarb (BEN) is an acutely toxic carbamate insecticide which used in public places and agriculture, it is also effective against a wide range of nuisance and disease vector insects. A new rapid and sensitive reverse flow injection spectrophotometric procedure coupled with on-line solid-phase reactor is designed in this article for the determination of BEN in its insecticidal formulations and water samples, by using three different solid-phase reactors containing bulk PbO2 (B-SPR), PbO2 nanoparticles (N-SPR) and grafted nanoparticles of SiO2-PbO2 (G-SPR) immobilized on cellulose acetate matrix (CA). This method of oxidative coupling is based on alkaline hydrolysis of the BEN pesticide, and then coupled with N,N dimethyl-p-phenylenediamine sulphate (DMPD) to give a blue color product which measured at λmax 675 nm. It worth to mentioned that under optimal conditions, Beer’s law is obeyed in the range of 1-175 μg mL-1 for B-SPR and 0.25-70 μg mL-1 of BEN for both N-SPR and G-SPR respectively within limit of detection (LOD) of 0.931, 0.234 and 0.210 μg mL-1 for B-SPR N-SPR and G-SPR respectively. The surface methodology of the solid phase was also investigated by using atomic force microscopy.

Automated Analysis of Organophosphorus Insecticides by Wet Digestion-Oxidation and Colorimetric Determination of the Derived Orthophosphate

1968 ◽  
Vol 51 (3) ◽  
pp. 697-708
Author(s):  
Daniel E Ott ◽  
Francis A Gunther
Keyword(s):  
Thin Layer ◽  
Automated Analysis ◽  
Automated System ◽  
Phosphorus Compounds ◽  
Colorimetric Determination ◽  
Total System ◽  
Blue Color ◽  
Automated Technique ◽  
Analytical System

Abstract Adaptation of an AutoAnalyzer system to the determination of phosphorus in organic compounds now provides an automated technique generally applicable for the analysis of organophosphorus inserticides. Following automated wet digestionoxidation of the compounds (some need preliminary alkaline hydrolysis) the resulting orthophosphate is determined automatically by a colorimetric system reading a phosphomolybdenum blue color at 815 mμ. The total system handles 10 samples per hour with a precision and sensitivity readily practical for organophosphorus insecticide analysis; the insecticidal solutions tested, at concentrations of 2 μg/ml or greater, gave repeatable responses within ± 10%. Manual cleanup procedures for most crop samples are required to remove interfering noninsecticidal phosphorus compounds before the system is applicable to total residue analyses. Thimet (phorate) and phosphamidon at 0.5 ppm in fortified stripping solutions of strawberries were analyzed separately without cleanup, however. Adsorption column chromatography on Florisil has provided rapid and efficient cleanup of fortified spinach extractives prior to automated analysis of Thimet and dimethoate. Autoanalysis of individual spots from thin layer chromatograms provides considerable specificity to this nonspecific analytical system, and for some crops provides all the cleanup necessary. Thin layer "spots" can be introduced directly into the automated system.

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