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.

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.

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

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.

Non-Destructive Measurement of the Internal Quality of Citrus Fruits Using a Portable NIR Device

2020 ◽  
Author(s):  
Carla S P Santos ◽  
Rebeca Cruz ◽  
Diogo B Gonçalves ◽  
Rafael Queirós ◽  
Mark Bloore ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Soluble Solids ◽  
Internal Quality ◽  
Total Acidity ◽  
Citrus Fruits ◽  
Citrus Industry ◽  
Total Vitamin ◽  
Non Destructive

Abstract The citrus industry has grown exponentially as a result of increasing demand on its consumption, giving it high standing among other fruit crops. Therefore, the citrus sector seeks rapid, easy, and non-destructive approaches to evaluate in real time and in situ the external and internal changes in physical and nutritional quality at any stage of fruit development or storage. In particular, vitamin C is among the most important micronutrients for consumers, but its measurement relies on laborious analytical methodologies. In this study, a portable near infrared spectroscopy (NIRS) sensor was used in combination with chemometrics to develop robust and accurate models to study the ripeness of several citrus fruits (oranges, lemons, clementines, tangerines, and Tahiti limes) and their vitamin C content. Ascorbic acid, dehydroascorbic acid, and total vitamin C were determined by HILIC-HPLC-UV, while soluble solids and total acidity were evaluated by standard analytical procedures. Partial least squares regression (PLSR) was used to build regression models which revealed suitable performance regarding the prediction of quality and ripeness parameters in all tested fruits. Models for ascorbic acid, dehydroascorbic acid, total vitamin C, soluble solids, total acidity, and juiciness showed Rcv2 = 0.77–0.87, Rcv2 = 0.29–0.79, Rcv2 = 0.77–0.86, Rcv2 = 0.75–0.97, Rcv2 = 0.24–0.92, and Rcv2 = 0.38–0.75, respectively. Prediction models of oranges and Tahiti limes showed good to excellent performance regarding all tested conditions. The resulting models confirmed that NIRS technology is a time- and cost-effective approach for predicting citrus fruit quality, which can easily be used by the various stakeholders from the citrus industry.

Note: Quantification of Ascorbic Acid and Dehydroascorbic Acid in Fresh Olives and in Commercial Presentations of Table Olives

2005 ◽  
Vol 11 (3) ◽  
pp. 199-204 ◽  
Author(s):  
A. López ◽  
A. Montaño ◽  
P. Garcia ◽  
A. Garrido
Keyword(s):  
Ascorbic Acid ◽  
High Performance Liquid Chromatography ◽  
Vitamin C ◽  
High Performance ◽  
Dehydroascorbic Acid ◽  
Maximum Level ◽  
Table Olives ◽  
Total Vitamin ◽  
Low Levels ◽  
To Come

Ascorbic acid (AA) and dehydroascorbic acid (DHAA) were determined by high performance liquid chromatography (HPLC) in fresh green olives as well as a diversity of commercial presentations of table olives (based on both Spanish-style green olives and directly brined olives). Fresh green olives (Manzanilla cv.) immediately after harvest contained about 9mg total ascorbic acid/100g f.w., with DHAA representing more than 90% of this amount. During the post-harvest period (till 2 weeks) the total vitamin C remained stable when olives were stored at 6°C, but significant degradation occurred at ambient temperature (~35% loss after 7 days). In commercial presentations of table olives, in general, the main contribution to the total vitamin C level appeared to come from AA added as an antioxidant, the maximum level being found in Manzanilla olives stuffed with anchovy streams (36.1mg/100g f.w.). However, in some samples (e.g. plain olives) that did declare any added AA, very low levels (0.1-0.6mg total AA/100g f.w.) were found. Our hypothesis is that, in those samples, AA would be degraded by lactic acid bacteria and/or yeast from olive fermentation, whereas pasteurisation in other presentations (e.g. stuffed olives) would stabilise added AA.

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