COLORIMETRIC DETERMINATION OF TITRATION CURVES WITHOUT BUFFER MIXTURES.

Louis J. Gillespie

doi:10.1021/ja01449a011

Titrimetric Determination of N,N′-Disubstituted p-Phenylenediamines

Rubber Chemistry and Technology ◽

10.5254/1.3539946 ◽

1962 ◽

Vol 35 (3) ◽

pp. 676-683 ◽

Cited By ~ 1

Author(s):

Otto Lorenz ◽

C. R. Parks

Keyword(s):

Rapid Detection ◽

Spot Test ◽

Nonaqueous Solvents ◽

Oxidation Products ◽

Colorimetric Determination ◽

Titration Curves ◽

Rubber Compounds ◽

Titrimetric Determination

Abstract Three types of p-phenylenediamine derivatives used extensively as antioxidants and antiozonants in rubber compounds are N,N′-di-sec-alkyl-, N-sec-alkyl-N′-aryl-, and N,N′-diaryl-p-phenylenediamines. Available methods for these compounds are based mainly on a colorimetric determination of their colored oxidation products, the Wurster's salts or the p-quinonediimines. The deep coloration of the Wurster's salts was used as the basis of a spot test for the rapid detection of these diamines in rubber compounds. This test permits one to differentiate the three types of p-phenylenediamines. An investigation of the neutralization of p-phenylenediamines in nonaqueous solvents showed that N,N′-di-sec-alkyl- and N-sec-alkyl-N′-aryl-p-phenylenediamines could be determined readily in this way. The N,N′-diaryl derivatives did not give satisfactory titration curves because of their low basicity. By the addition of chloranil, however, diaryl-p-phenylenediamines were oxidized to the Wurster's salts with the formation of one equivalent of base which could be neutralized by acid. A similar procedure was applicable to the determination of N,N′-diaryl-p-quinonediimines, or mixtures of these diamines and diimines.

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A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

Gastroenterology ◽

10.1016/s0016-5085(59)80003-2 ◽

1959 ◽

Vol 36 (2) ◽

pp. 193-201 ◽

Cited By ~ 46

Author(s):

Julius A. Goldbarg ◽

Esteban P. Pineda ◽

Benjamin M. Banks ◽

Alexander M. Rutenburg

Keyword(s):

Enzymatic Activity ◽

Colorimetric Determination ◽

Health And Disease ◽

Urine Serum

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Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v12i7.6703 ◽

2013 ◽

Vol 12 (7) ◽

pp. 460-465

Author(s):

Sameer Amereih ◽

Zaher Barghouthi ◽

Lamees Majjiad

Keyword(s):

Drinking Water ◽

Detection Limit ◽

Complex Formation ◽

Molar Absorptivity ◽

Colorimetric Determination ◽

Zirconium Complex ◽

Reliable Determination ◽

Percentage Recovery ◽

Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

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

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.10.2.2 ◽

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.

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