Quantitative Determination of Coumestrol in Dried Alfalfa and Alfalfa Leaf Protein Concentrates Containing Chlorophyll

1975 ◽  
Vol 58 (5) ◽  
pp. 983-986
Author(s):  
Benny E Knuckles ◽  
Raymond E Miller ◽  
E M Bickoff
Keyword(s):  
Quantitative Determination ◽  
Analytical Method ◽  
Leaf Protein ◽  
Improved Method ◽  
Alcohol Extract ◽  
Protein Concentrates ◽  
Coefficients Of Variation ◽  
Lower Standard ◽  
Alfalfa Leaf

Abstract An improved analytical method for the determination of coumestrol in dried alfalfa and leaf protein concentrates is described. In this method, chlorophyll is removed from an alcohol extract prior to the paper chromatographic-fluorometric measurement of coumestrol. Ninety-eight per cent of the coumestrol added to alfalfa leaf protein concentrates is recovered by this method. This improved method gives replicate values with lower standard deviations and coefficients of variation than the literature method.

Validation of an analytical method for the quantitative determination of selenium in bacterial biomass by ultraviolet–visible spectrophotometry

2018 ◽  
Vol 255 ◽  
pp. 182-186 ◽  
Author(s):  
Ana Paula Mörschbächer ◽  
Anja Dullius ◽  
Carlos Henrique Dullius ◽  
Cassiano Ricardo Bandt ◽  
Daniel Kuhn ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Analytical Method ◽  
Bacterial Biomass ◽  
Visible Spectrophotometry

Improved Method for Determination of Sulfites in Shrimp

1993 ◽  
Vol 76 (3) ◽  
pp. 565-569 ◽  
Author(s):  
Arantza Armentia-Alvarez ◽  
M Jesus Peña-Egedo ◽  
Concepcion Garcia-Moreno
Keyword(s):  
Aluminum Oxide ◽  
Improved Method ◽  
Edible Part ◽  
Coefficients Of Variation

Abstract A method for the determination of sulfites in shrimp developed by Kim and Kim and modified by Paino-Campa et al. for sausages has been further modified. Total sulfites are extracted by initially adding aluminum oxide to the sample and using an extraction solution at pH 12. In the reproducibility assays, coefficients of variation (CVs) were 4.8% for free sulfite and 7.8% for total sulfite in the edible part of the shrimp. In the inedible part, CVs were 7.5% and 8.9% for free and total sulfite, respectively. Mean recovery was 87.8% for the edible part and 84.4% for the inedible part of the shrimp. The method was compared with the optimized Monier- Williams method. The results obtained with both methods for determination of total SO2 in the edible part of the shrimp did not show significant differences (P= 0.05).

Improved Method for Determination of Polynuclear Aromatic Hydrocarbons in Pharmacopoeial Paraffin and Mineral Oils

1991 ◽  
Vol 74 (6) ◽  
pp. 968-973
Author(s):  
Aziz Geahchan ◽  
I Le Gren ◽  
Paul Chambon ◽  
Renee Chambon
Keyword(s):  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Aromatic Hydrocarbons ◽  
Detectable Level ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Improved Method ◽  
Fluorometric Determination ◽  
Mineral Oils

Abstract An improved method has been developed for quantitative determination of poiynuciear aromatic hydrocarbons (PAHs) in pharmacopoeial paraffin and medicinal white oil samples. This new method combines 2 liquid-liquid partition and adsorption chromatography procedures with a 2-step purification on Sephadex LH 20 and liquid chromatography with fluorometric determination. Selective elution of PAHs results in absence of background fluorescence. The minimum detectable level ranges from 0.2 ppt for benzofluoranthene isomers to 200 ppt for acenaphthene. Recoveries of PAHs added at 7 ppm varied from 92.1 to 111.4%. When a variety of medicinal white oil samples were analyzed by this improved method, 27 PAHs were identified, including 11 suspected carcinogens. Their identities were confirmed by capillary gas chromatography.

Gas Chromatographic Determination of Dioxathion and Chlorfenvinphos in Emulsifiable Formulations and Livestock Dips

1970 ◽  
Vol 53 (3) ◽  
pp. 566-568
Author(s):  
J E Paterson
Keyword(s):  
Quantitative Determination ◽  
Chromatographic Analysis ◽  
Chromatographic Method ◽  
Silicone Oil ◽  
Chromatographic Determination ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of dioxathion and chlorfenvinphos in emulsifiable concentrates and livestock dips. A convenient quantity of the emulsifiable formulation is dissolved in xylene and the aqueous dip is extracted with xylene for gas chromatographic analysis, using a mixed silicone oil stationary phase and a flame ionization detector. The coefficients of variation for the dioxathion and chlorfenvinphos determinations in the emulsifiable concentrate are 2.4 and 1.0%, respectively. Recoveries of the former from a fouled dip ranged from 97 to 103% and recoveries of the latter ranged from 92 to 97%.

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