Colorimetric determination of the dissociation constant of acetic acid

1959 ◽  
Vol 36 (6) ◽  
pp. 289 ◽  
Author(s):  
Wendell Forst
Keyword(s):  
Acetic Acid ◽  
Dissociation Constant ◽  
Colorimetric Determination

Conductometric and Colorimetric Determination of Volatile Acidity of Vinegars by Flow-Injection Analysis

1991 ◽  
Vol 74 (2) ◽  
pp. 346-350 ◽  
Author(s):  
Matthieu Tubino ◽  
Flavio G Barros
Keyword(s):  
Acetic Acid ◽  
Colorimetric Determination ◽  
Bromocresol Purple ◽  
Water Stream ◽  
Ptfe Membrane ◽  
Volatile Acidity ◽  
Relative Standard ◽  
Significant Difference ◽  
Membrane Separator

Abstract Recent methods for determination of the volatile acidity of vinegars are relatively slow (about 40 mln) and involve techniques subject to a variety of errors (ca 2.5%). The present paper describes a method that provides results in a shorter time (ca 2 mln, Including dilution), with a smaller relative error rate (ca 1%). Conductometric analysis consists of the Injection of the sample In a deionlzed water stream that then flows past a PTFE membrane separator. Acetic acid diffuses through the membrane to another deionlzed water stream that passes through a conductivity cell. Colorimetric analysis also consists of sample injection into a deionlzed water stream that passes through the same PTFE membrane separator. However, the acetic acid diffuses into a bromocresol purple solution stream at pH 7. This solution passes through a flow cell In a spectrophotometer set at 540 nm. Before injection, samples were treated with hydrogen peroxide to ensure complete oxidation of sulfite to sulfate. Results of the proposed method were also compared with another similar method. At a 95% confidence level, the statistical t-test Indicates no significant difference between them. Typical estimates of the relative standard deviations obtained with the new methods are ca 1%. Analyses were performed with red and white wine vinegars.

Effects of Tomatine on the Colorimetric Determination of Cholesterol by the Zak Procedure

1967 ◽  
Vol 13 (6) ◽  
pp. 468-474 ◽  
Author(s):  
Cleamond D Eskelson ◽  
Arthur L Dunn ◽  
Clarence R Cazee
Keyword(s):  
Acetic Acid ◽  
Free Cholesterol ◽  
Colorimetric Determination ◽  
Acid Reagent ◽  
Standard Solution

Abstract The iron-acetic acid reagent used for cholesterol determinations produces a color with tomatine, which is reported to be a more specific precipitant for cholesterol. To circumvent the interferen:e of tomatine found in a cholesterol-tomatinide complex, a standard solution containing stoichiometric amounts of tomatine and cholesterol was used and proved to be reliable for the determination of free cholesterol in serum.

Experimental Improvements on Determination of Dissociation Constant of Acetic Acid by Conductometry

Daxue Huaxue ◽  
2016 ◽  
Vol 31 (6) ◽  
pp. 58-61
Author(s):  
Yu-Huan CHEN ◽  
◽  
◽  
Shu-Ming ZHANG ◽  
Gui-Xiang WANG ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Dissociation Constant

Colorimetric Determination of Thymol and Eugenol in Volatile Oils

1978 ◽  
Vol 61 (1) ◽  
pp. 169-171
Author(s):  
Mohamed A Korany ◽  
Nabil Abdel-Salam ◽  
Mohamed Abdel-Salam
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide Solution ◽  
Colorimetric Method ◽  
Aqueous Acetic Acid ◽  
Colorimetric Determination ◽  
Clove Oil ◽  
Volatile Oils ◽  
Thyme Oil ◽  
Yellow Color

Abstract A colorimetric method for determining thymol and eugenol in volatile oils is presented. Thymol and eugenol are reacted with sodium cobaltinitrite in aqueous acetic acid. The yellow color produced is measured at 330 and 370 nm in chloroform, and at 396 and 450 nm in sodium hydroxide solution for thymol and eugenol, respectively. The method is applied to the assay of thyme oil (thymol type) and clove oil. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.

Colorimetric determination of ethylenediaminetetra-acetic acid in foods

1985 ◽  
Vol 180 (4) ◽  
pp. 280-283 ◽  
Author(s):  
Takashi Hamano ◽  
Yukimasa Mistuhashi ◽  
Kisaku Tanaka ◽  
Yukio Matsuki ◽  
Yoshikiyo Oji ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Colorimetric Determination

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

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
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

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

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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