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Biomedical subjects

E D Coppola

Publications and source records attributed to E D Coppola.

At least 19 recordsLinked to original sources
PubMed1978

High pressure liquid chromatographic determination of major organic acids in cranberry juice.

A reverse phase high pressure liquid chromatographic method is presented for the simultaneous separation and determination of quinic, malic, and citric acids in single strength, undiluted cranberry juice. After a 1 : 10 dilution and cleanup through a disposable column, major organic acids in cranberry juice are separated on a Bondapak/C18 column and quantitated by using a differential refractometer. Twenty-seven samples of different single strength cranberry juice were analyzed using this method; the mean content of quinic, malic, and citric acids were 1.32 (std dev. 0.150), 0.92 (std dev. 0.079), and 1.08% (std dev. 0.111), respectively. Mean percent recoveries of each acid were quinic 95.4 (std dev. 6.8), malic 96.6 (std dev. 5.8), and citric 94.0% (std dev. 4.8).

Acids↗
PubMed1976

Nitrite in meat products determined by fluorescence quenching of p-aminobenzoate ion.

A direct fluorometric method is presented for determining nitrites in meat products by means of quenching. The extracted sodium nitrite is consumed in a diazotization reaction with a measured excess of the fluorescent reagent p-aminobenzoic acid (PABA) in boiling water and at pH less than or equal to 1.4. The amount of decrease in fluorescence (quenching) of PABA, in alkaline medium (pH 11.0) with excitation at 265 nm and fluorescence at 339 nm, is directly related to the amount of nitrite present. The slope for that standard curve is 1% decrease in relative fluorescence intensity per 2.76 ppm NaNO2. Results obtained for a series of 20 meat samples analyzed by this fluorometric method are in good agreement with results obtained by a colorimetric method with an average difference of +/- 6.1 ppm NaNO2.

Aminobenzoates↗
PubMed1975

Fast, short-column separation and fluorometric determination of monosodium glutamate in foods.

In a simple and fast procedure, monosodium glutamate in food products is first separated by a short ion exchange column and subsequently determined fluorometrically with fluorescamine. An average recovery of 90.8% with a standard deviation of plus or minus 6.67% was obtained for added monosodium glutamate in a series of 8 products. As little as 0.05% monosodium glutamate can be determined. The method is faster than the official method and saves 5 hr/determination.

Chromatography, Ion Exchange↗
PubMed1975

Fluorometric determination of nitrite in cured meats.

An indirect fluorometric method for determining sodium nitrite in meat products is presented. The extracted sodium nitrite is consumed in a diazotization reaction with a measured excess of sulfanilic acid. Fluorescamine, which acts selectively with primary amines such as sulfanilic acid, is a fluorogenic reagent for the excess amine. The amine consumed, calculated by difference from the total originally present, is directly related to the sodium nitrite content of the sample. Interferences from amino acids and soluble proteins in the meat extract are eliminated by judicious use of a secondary peak in the fluorescence spectra (436 nm excitation, 495 nm fluorescence) combined with measurement at low pH (3.30). The recoveries of sodium nitrite ranged from 83.2 to 99.6% with an average of 93.4 and a standard deviation of +/- 5.28% for 11 determinations.

Food Additives↗