Polarographic determination of vitamin C after derivatization with o-phenylenediamine

2010 ◽  
Vol 75 (7) ◽  
pp. 731-741 ◽  
Author(s):  
José António Rodrigues ◽  
Inês Maria Valente ◽  
Luís Moreira Gonçalves ◽  
João Grosso Pacheco ◽  
Aquiles Araújo Barros
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Hydrolytic Degradation ◽  
Dehydroascorbic Acid ◽  
Differential Pulse ◽  
Fruit Juices ◽  
Polarographic Determination ◽  
Initial Oxidation ◽  
The Common

A differential pulse polarographic (DPP) method has been developed for the determination of ascorbic acid (AA) and dehydroascorbic acid (DHA), the two main forms of Vitamin C. The method consists of the DPP analysis of a quinoxaline obtained by the derivatization of DHA with o-phenylenediamine. Results using the proposed method correlated well with those obtained by two reference methodologies: the common iodometric method and a published chromatographic methodology. It was also used in the study of Vitamin C degradation in fruit juices, showing that it involves an initial oxidation of AA to DHA, followed by hydrolytic degradation of the latter.

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.

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

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.

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.

Differential-pulse polarographic determination of iron in acids, waters, fruit juices and wines

The Analyst ◽  
1994 ◽  
Vol 119 (7) ◽  
pp. 1571-1574 ◽  
Author(s):  
M. E. Vázquez Diaz ◽  
J. C. Jiménez Sánchez ◽  
M. Callejón Mochón ◽  
A. Guiraúm Pérez
Keyword(s):  
Differential Pulse ◽  
Fruit Juices ◽  
Polarographic Determination

scholarly journals PENGARUH METODE PENGGERUSAN TABLET VITAMIN C TERHADAP KADAR BAHAN AKTIF

2019 ◽  
Vol 4 (2) ◽  
pp. 94
Author(s):  
Damaranie Dipahayu Dipahayu ◽  
Silfiana Nissa Permatasari
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dosage Form ◽  
Ascorbic Acid Content ◽  
Hplc Method ◽  
Active Ingredients ◽  
Grinding Method ◽  
The Common ◽  
Grinding Technique

One form of prescription service is preparing pulveres dosage form. Pulveres are generally obtained from the grinding technique of several tablet preparations and mixing them. The common grinding technique is manually using a mortar-stamper and a blender (pulverization machine). The use of a blender is considered more practical and shortens the time but the heat of blender can reduce levels of active ingredients which is unstable of high temperature. This study aims to determine whether the manual grinding method and blender of vitamin C tablets will affect the levels of active ingredients. Determination of levels of active ingredients of vitamin C tablets that was crushed by the HPLC method. Based on the results of the study, it is known that the levels of manually crushed vitamin C are 191,919 mg and 192,872 mg, while the blended vitamin C levels are 181,204 mg and 179,886 mg. The conclusion of this study shows that the blender method can cause a decrease in vitamin C levels greater than the manual method however, both methods can still maintain the availability of ascorbic acid content in the concentration range of 90% - 110.0%.

scholarly journals The effect of selected substances on the stability of standard solutions in voltammetric analysis of ascorbic acid in fruit juices

2019 ◽  
Vol 17 (1) ◽  
pp. 655-662
Author(s):  
Radosław Kowalski ◽  
Artur Mazurek ◽  
Urszula Pankiewicz ◽  
Marzena Włodarczyk-Stasiak ◽  
Monika Sujka ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Room Temperature ◽  
Nutritive Value ◽  
Fruit Juices ◽  
Optimum Concentration ◽  
Voltammetric Analysis ◽  
The Stability ◽  
Standard Solutions

AbstractThe objective of the study was to identify suitable additives stabilizing standard solutions of ascorbic acid (AA) that would not cause interference in the analytical process with the use of voltammetry in the determination of the AA content in food products. In addition, the effect of various conditions of storage of selected fruit juices and drinks on the concentration of vitamin C was studied. The study demonstrated that AA degradation was inhibited the most effectively by tartaric acid and its optimum concentration was set to 200 mg L-1. Analysis of selected fruit juices stored in various temperature conditions confirmed that an elevation of temperature and extension of the time of storage caused a decrease in the content of vitamin C in the analyzed samples, while closing the packages caused a limitation of the changes in concentration of this vitamin. On the basis of literature data and of the results obtained in the present study it can be concluded that fruit juices should be stored at a temperature lower than room temperature to retain their nutritive value.

The determination of vitamin C in evaporated and fortified sterilized milks

1970 ◽  
Vol 37 (3) ◽  
pp. 521-527 ◽  
Author(s):  
Joyce Toothill ◽  
S. Y. Thompson ◽  
W. B. Hill
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Chromatographic Separation ◽  
Dehydroascorbic Acid ◽  
Reconstituted Milk

SummaryA study has been made of the use of 2,6-dichlorophenolindophenol (DCP) and also of 2,4-dinitrophenylhydrazine (DNPH) with and without chromatography of the DNPH derivatives, for the determination of ascorbic acid (AA) and dehydroascorbic acid (DHA) in evaporated milks, and of AA in AA-fortified sterilized milks.In the DNPH method, when interfering compounds were removed by the chromatographic separation of the DNPH derivatives, absorption curves typical of the pure DHA derivative were obtained.The DCP method gave erroneously high values for the AA and DHA content, and the lower values obtained by the DNPH method with chromatography of the DNPH derivatives were judged correct. Thus for an evaporated milk, the values for vitamin C content (AA + DHA) were, in mg/100ml reconstituted milk, 0·88 (DCP method), 0·66 (DNPH method without chromatography), and 0·48 (DNPH method combined with chromatography). The AA contents (mg/100 ml) of the 2 fortified sterilized milks were 3·63 and 5·78 (DCP method); 3·01 and 4·28 (DNPH method combined with chromatography).The AA contents of the 5 different evaporated milks, determined by chromatography of the DNPH derivatives, ranged from 0·07 to 0·63 mg/100 ml reconstituted milk. The DHA content was negligible.As judged by the shape of the absorption curves after chromatography of the DNPH derivatives, it is concluded that this method is the most reliable of those studied.

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