Komarowsky Color Reaction for Aliphatic Alcohols. Liminations and Sensitivity

Coles, Harold W.; Tournay, William

doi:10.1021/i560101a007

Cited by 13 publications

(2 citation statements)

References 2 publications

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“…This commm~ication reports on the factors governing reproducible quantitative assay of piperine with the above reagent. Also given are data on the reaction with concentrated sulfuric acid plus other aromatic alclehycles, known as the Komarowsky reaction (Coles and Tournay, 1942 ;Nogare and Mitchell, 1953 (Marion, 1950) and recrystallized from alcohol to a constant melting point of 129-13O"C, and the purity was checked by the ultraviolet method (Fagen et al, 1955). Sulfuric acid was reagent grade, 95-98%, sp.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Determination of Piperine. I. The Komarowsky Reaction

Graham

1965

Journal of Food Science

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SUMMARY A highly stable reagent consisting of para‐dimethylaminobenzaldehyde (I) or para‐hydroxybenzaldehyde (II) or other cylic aldehydes, plus thioureau in concentrated sulfuric acid, has been developed for use in determining piperine. The slightly yellow reagent, if stored under refrigeration in a brown bottle, maintains a constant chromogenic capacity for 4–6 weeks. Piperine when heated with this reagent for 15 min at 100°C develops a red color (I max. 490 mp) or purple color (II max. 570 mμ) whose intensity is proportional to the amount of piperine present. Water inhibits color development, but a small amount of methyl alcohol is necessary. Ethyl alcohol cannot be used, since it develops color with the reagent. Critical factors for reproducible, quantitative assay are the concentration of acid and thiourea in the reagent and the time and temperature of heating the reaction mixture. For I, the most sensitive of the aldehydes used, good precision, with a standard deviation of it ± 3470, was attained. Between the levels of 0.01 and 0.06μM of piperine per ml of reagent, there is a linear relation which may be described by the least‐squares equation. X = 0.088 Y + 0.00175 where X = concentration (μM) of piperine per ml of reagent Y = absorbance at 490 μM Percent piperine in sample = X (0.28533) (dilution factor)′ 100 Sample weight (mg)

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Section: Introductionmentioning

confidence: 99%

Quantitative Determination of Piperine. I. The Komarowsky Reaction

Graham

1965

Journal of Food Science

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“…Previous workers have studied in some detail the color reactions between aromatic aldehydes and alcohols in concentrated sulfuric or hydrochloric acid (Komarowsky reaction). Both dehydration (5,9) and aldol condensation (7) have been suggested as steps in the reaction. It seemed possible, as suggested (£?…”

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confidence: 99%

Spectrophotometric Determination of Olefins

Altshuller¹,

Sleva²

1961

Anal. Chem.

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Beer Flavour: I. Volatile Products of Fermentation: A Review

Stevens

1960

Journal of the Institute of Brewing

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The flavour of beer and other fermented beverages is conditioned by the volatile components present. Many of these compounds are concentrated into the higher alcohol or fusel oil fraction. The various substances which have been identified in fusel oils are discussed together with the methods available for their analysis and the values obtained when these methods are applied to beers, wines and spirits. The biochemical pathways which have been proposed for the formation of the higher alcohols as well as diacetyl and its precursors during fermentation are also considered. Mention is made of the physiological effects of these compounds.

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Komarowsky Color Reaction for Aliphatic Alcohols. Liminations and Sensitivity

Cited by 13 publications

References 2 publications

Quantitative Determination of Piperine. I. The Komarowsky Reaction

Quantitative Determination of Piperine. I. The Komarowsky Reaction

Spectrophotometric Determination of Olefins

Beer Flavour: I. Volatile Products of Fermentation: A Review

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