scholarly journals Rapid determination of ascorbic acid, dehydroascorbic acid, and total vitamin C by electrochemiluminescence with a thin-layer electrochemical cell

2009 ◽  
Vol 393 (6-7) ◽  
pp. 1669-1675 ◽  
Author(s):  
Fumiki Takahashi ◽  
Jiye Jin
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Thin Layer ◽  
Electrochemical Cell ◽  
Rapid Determination ◽  
Dehydroascorbic Acid ◽  
Total Vitamin

Determination of Total Vitamin C by Ion Exclusion Chromatography with Electrochemical Detection

1989 ◽  
Vol 72 (4) ◽  
pp. 681-686
Author(s):  
Hie-Joon Kim
Keyword(s):  
Ascorbic Acid ◽  
Sulfuric Acid ◽  
Vitamin C ◽  
Retention Time ◽  
Acid Content ◽  
High Speed ◽  
Reference Electrode ◽  
Dehydroascorbic Acid ◽  
Total Vitamin

Abstract A rapid and sensitive liquid chromatographic method for determination of total vitamin C in foods and beverages is described. Ascorbic acid and dehydroascorbic acid are extracted with sulfuric acid solution, and the dehydroascorbic acid in the extract is reduced to ascorbic acid by dithiothreitol at pH 7. The reduction is complete in 2 min at room temperature. The resulting total ascorbic acid is separated on an anion exclusion/high speed column with 20mM sulfuric acid as eluant and detected amperometrically with a platinum electrode operating at +0.6-0.8 V vs Ag/AgCl reference electrode. Dithiothreitol (retention time, 3.2 min) does not interfere with the separation and detection of ascorbic acid (retention time, 1.3 min). The dehydroascorbic acid content can be estimated as the difference in ascorbic acid content measured with and without reduction by dithiothreitol. The completeness of the reduction was demonstrated by purposely allowing the oxidation of ascorbic acid in the food extract and determining the total vitamin C after reduction. The determinations of vitamin C content in selected foods and beverages were in good agreement with the expected values. Total analysis time for vitamin C is 10 min and the detection limit is 0.1 ng. The method is specific for vitamin C, and interference by other food constituents is minimal.

Automated Fluorometric Method for the Determination of Total Vitamin C in Food Products

1976 ◽  
Vol 59 (6) ◽  
pp. 1244-1250 ◽  
Author(s):  
Ram B Roy ◽  
Aldo Conetta ◽  
Jerry Salpeter
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Food Products ◽  
Total Vitamin ◽  
Automated Method ◽  
Highly Sensitive ◽  
Aoac Method ◽  
Analytical System

Abstract A specific microfluorometric method for the determination of ascorbic acid, dehydroascorbic acid, and total vitamin C in food products has been automated. The procedure developed is an adaptation of the official AOAC method (secs. 43.056–43.062), except that N-bromosuccinimide is used instead of Norit to oxidize vitamin C. Ascorbic acid is selectively oxidized by N-bromosuccinimide before other interfering substances that may be present, so this method is a highly sensitive and specific technique with extensive applicability. The proposed automated method is simple, rapid, reliable, and sufficiently sensitive to analyze as little as 2 × 10−3 to 0.1 mg ascorbic acid/ml. Analytical results obtained for ascorbic acid, dehydroascorbic acid, and total vitamin C in a wide variety of food products are reported. The analytical system developed has the capability of analyzing 50 samples/hr.

Observations on the use of 2,4-dinitrophenylhydrazine and of 2,6-dichlorophenolindophenol for the determination of vitamin C in raw and in heat-treated milk

1970 ◽  
Vol 37 (1) ◽  
pp. 29-45 ◽  
Author(s):  
Joyce Toothill ◽  
S. Y. Thompson ◽  
J. Edwards-Webb
Keyword(s):  
Escherichia Coli ◽  
Heat Treatment ◽  
Ascorbic Acid ◽  
Vitamin C ◽  
Thin Layer ◽  
Dehydroascorbic Acid ◽  
Heat Treated ◽  
Sterilized Milk ◽  
Layer Chromatography

SummaryA study has been made of methods using 2,4-dinitrophenylhydrazine (DNPH) or 2,6-dichlorophenolindophenol (DCP) for the determination of vitamin C (ascorbic acid+dehydroascorbic acid) in raw, UHT processed, evaporated and sterilized milk.Interfering substances were not detected in milk that had received a heat treatment no more severe than 145°C for 4 s (UHT process), so that either reagent could be used.With more drastic heat treatment, interfering substances were formed and only the DNPH method with column and thin layer chromatography of the DNPH derivatives was specific for vitamin C. With in-bottle sterilized milk, the values for ascorbic acid were (in mg/100 ml) 1·16 (DCP method with H2S reduction); 0·58 (DCP method with Escherichia coli reduction); 0·64 (DNPH method); 0·33 (DNPH method combined with chromatography).In our experience the DNPH method combined with chromatography of the derivatives is highly specific for vitamin C and should be used to check the results obtained by other and simpler methods.

Chromatographic and Extraction Techniques for Vitamin C Assay

1965 ◽  
Vol 48 (5) ◽  
pp. 985-991
Author(s):  
Elmer De Ritter
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Thin Layer ◽  
Dehydroascorbic Acid ◽  
Reduced Form ◽  
Extraction Techniques ◽  
Total Vitamin ◽  
High Efficient ◽  
Efficient Extraction ◽  
Layer Chromatography

Abstract A review is presented of chromatographic procedures used in the assay of vitamin C. Paper, thin layer, and column chromatography have been used to advantage for separating interfering substances. Even the closely related erythorbic acid, which has no vitamin C activity, can be separated from ascorbic acid by various techniques on paper. Total vitamin C can be determined chromatographically after reduction of dehydroascorbic acid with H2S or after oxidation of the reduced form to dehydroascorbic acid. A combination of column and thin layer chromatography on silica gel of the dinitrosazone formed by reaction of dehydroascorbic acid with 2,4-dinitrophenylhydraiine is recommended as an effective method for achieving specificity in vitamin C assays of foods and feeds where the level of interference is high. Efficient extraction procedures are described for determining added ascorbic acid in feeds and mineral premixes.

Automated Analysis of Vitamin C in Pharmaceutical Products

1975 ◽  
Vol 58 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Omer Pelletier ◽  
Rene Brassard
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Pharmaceutical Preparations ◽  
Automated Analysis ◽  
Pharmaceutical Products ◽  
Copper Salts ◽  
Total Vitamin ◽  
Automated Method

Abstract The determination of total vitamin C in the form of both L-ascorbic acid (AA) and dehydroascorbic acid (DHAA) present in pharmaceutical preparations has been automated. Total vitamin C (completely oxidized to DHAA) was determined by reaction with 2,4-dinitrophenylhydrazine while blanks utilized the same reagent after reducing all DHAA to AA. The automated method was applicable to a variety of multivitamin preparations including those containing iron and copper. The mean recovery of L-ascorbic acid added to 11 multivitamin preparations was 99.4% with a coefficient of variation of 2.5%. In the analysis of these products, results obtained by the automated method were essentially the same as those obtained by the original manual method. For preparations containing no copper salts, the results were also comparable to those obtained by titration with 2,6-dichloroindophenoI except in 1 product which contained some DHAA.

Notizen: Improved 2,4-Dinitrophenylhydrazine, Thin Layer Chromatography Methods for the Determination of Micro- and Macroamounts of Ascorbic Acid

1974 ◽  
Vol 29 (11-12) ◽  
pp. 777-780 ◽  
Author(s):  
A. Navon ◽  
H. Z. Levinson
Keyword(s):  
Acetic Acid ◽  
Vitamin C ◽  
Thin Layer ◽  
Condensation Reaction ◽  
Dehydroascorbic Acid ◽  
Previous Method ◽  
Aqueous Acetic Acid ◽  
Tlc Plates ◽  
Layer Chromatography

Microamounts of vitamin C could be readily determined in 20 μl-samples using the 2,4-dinitrophenylhydrazine method together with separation by thin layer chromato­graphy. The condensation reaction was carried out for 5 min at 100 °C on a glass fibre disc. Purification of vitamin C hydrazones was accomplished by repeated separation on TLC plates. An aqueous solution of 65% acetic acid was em­ployed to dissolve the vitamin C hydrazones, providing maxi­mal absorbance at 500 nm. The minimum amount detectable by this method is 0.4 μg of dehydroascorbic acid. The macrodetermination of vitamin C was improved by simpli­fying a previous method and employing 65% aqueous acetic acid as a solvent for the hydrazones.

scholarly journals Development and validation of a differential pulse polarography method for determination of total vitamin C and dehydroascorbic acid contents in foods

LWT ◽  
2020 ◽  
Vol 118 ◽  
pp. 108828
Author(s):  
Artur Mazurek ◽  
Marzena Włodarczyk-Stasiak ◽  
Urszula Pankiewicz ◽  
Radosław Kowalski ◽  
Jerzy Jamroz
Keyword(s):  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Total Vitamin ◽  
Pulse Polarography ◽  
Development And Validation

Liquid Chromatography, Microfluorometry, and Dye-Titration Determination of Vitamin C in Fresh Fruit and Vegetables

1983 ◽  
Vol 66 (6) ◽  
pp. 1377-1379
Author(s):  
Ron B H Wills ◽  
Pushparany Wimalasirl ◽  
Heather Greenfield
Keyword(s):  
Ascorbic Acid ◽  
Liquid Chromatography ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Fresh Fruit ◽  
Fruit And Vegetables ◽  
End Point ◽  
Liquid Chromatographic ◽  
Good Agreement

Abstract The vitamin C content of several fresh fruit and vegetables was determined by a liquid chromatographic (LC) method which gave simultaneous separate values for ascorbic acid and dehydroascorbic acid (DHA) and by the official AOAC methods of microfluorometry and dye-titration. The levels of ascorbic acid obtained by LC and dye-titration were in good agreement, except for a few colored products where it was difficult to determine the end point of the titration. The combined values for ascorbic acid and DHA obtained by LC and microfluorometry were in agreement for most produce, but for about one-third of the samples, the values obtained by microfluorometry were significantly higher.

Determination of Total Vitamin C in Various Food Matrixes by Liquid Chromatography and Fluorescence Detection

1992 ◽  
Vol 75 (5) ◽  
pp. 887-890 ◽  
Author(s):  
Karen Y Dodson ◽  
Edna R Young ◽  
Abdel-Gawad M Soliman
Keyword(s):  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Green Beans ◽  
Total Vitamin ◽  
Liquid Chromatographic Method ◽  
Medical Foods ◽  
Canned Corn ◽  
Liquid Chromatographic ◽  
Fluorescent Derivative

Abstract A liquid chromatographic method was developed for quantitation of total vitamin C content in various food matrixes. The method includes extraction with 3% mete-phosphoric acid-acetic acid and oxidation of ascorbic acid to dehydroascorbic acid with Norit, followed by reaction with ophenylenediamine to form a fluorescent derivative. The fluorescent derivative is separated on a µBondapak C18 (10 µm) column with methanol-water (55 + 45) and detected fluorometrically. This method is demonstrated to be suitable for several sample matrixes, including complex matrixes of canned corn, potatoes, green beans, potato chips, and cereals. Other products analyzed include infant formula, medical foods, fruit juice, and multivitamin tablets. Recoveries are in the range of 90-108%. Comparison of results with those by the AOAC fluorometric method shows excellent agreement.

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