Ascorbic acid determination in biological fluids using ascorbate oxidase immobilized on alkylamine glass beads in a flow injection potentiometric system

1994 ◽  
Vol 44 (1) ◽  
pp. 81-89 ◽  
Author(s):  
I. D. H. C. Marques ◽  
E. T. A. Marques ◽  
A. C. Silva ◽  
W. M. Ledingham ◽  
E. H. M. Melo ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Flow Injection ◽  
Biological Fluids ◽  
Glass Beads ◽  
Ascorbate Oxidase ◽  
Ascorbic Acid Determination ◽  
Alkylamine Glass ◽  
Acid Determination

scholarly journals The comparison of techniques and methods for L-ascorbic acid determination in the fruits

2012 ◽  
Vol 66 (4) ◽  
pp. 553-558 ◽  
Author(s):  
Biljana Cvetkovic ◽  
Radomir Malbasa ◽  
Eva Loncar ◽  
Zvonko Njezic ◽  
Olivera Simurina ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Acetic Acid ◽  
Vitamin C ◽  
Ascorbate Oxidase ◽  
Local Market ◽  
Acid Extraction ◽  
Metaphosphoric Acid ◽  
Significant Difference ◽  
Ascorbic Acid Determination ◽  
Acid Determination

Vitamin C is an essential vitamin for human nutrition; with the L-ascorbic acid (AA) being the active form of vitamin C. Hence, determination of the L-ascorbic acid in the natural and processed foods is very important. In the past, plenty of methods based on the reversible redox reaction of AA oxidation/DHA reduction were developed. Because of L-ascorbic acid instability in aqueous solutions, it is useful to analyze various types of extraction. The aim of this study is to compare three different methods and three different extractants for the L-ascorbic acid determination. Fruits (kiwi, lemon, orange, and grapefruit) were purchased from a local market. The L-ascorbic acid in these four samples was determined by the three different methods: the AOAC, the HPLC method with three different types of extractions, and the colorimetric method using ascorbate-oxidase. For the HPLC measurements, one part of the fruits was extracted with distilled water, the second with potassium hydrogen phosphate, and the third with 3% meta-phosphoric acid (MPA) in 8% acetic acid. The HPLC measurements of each sample were repeated three times, the AOAC titration was repeated five times, and in the calorimetric method three measurements were performed. The results were statistically evaluated related to sample basis. Statistical analysis shows that there is a significant difference between the results for all three methods of extraction for all samples, except for the grapefruit sample where no significant difference was observed between the results obtained after the buffer extraction (E2) and the metaphosphoric acid in acetic acid extraction (E3). Discriminative analysis for the HPLC determinations proves that there is a clear difference and defined border between the samples in relation to the methods of extraction during the HPLC determination.

Ascorbic acid biosensor using ascorbate oxidase immobilized on alkylamine glass beads

1992 ◽  
Vol 32 (1-3) ◽  
pp. 73-78 ◽  
Author(s):  
E. T. A. Marques ◽  
J. L. Lima Filho
Keyword(s):  
Ascorbic Acid ◽  
Glass Beads ◽  
Ascorbate Oxidase ◽  
Alkylamine Glass

scholarly journals Ascorbate Oxidase-Based Amperometric Biosensor for L-Ascorbic Acid Determination in Beverages

2016 ◽  
Vol 54 ◽  
Author(s):  
Gábor Csiffáry ◽  
◽  
Péter Fűtő ◽  
Nóra Adányi ◽  
Attila Kiss ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Amperometric Biosensor ◽  
Ascorbate Oxidase ◽  
Ascorbic Acid Determination ◽  
Acid Determination

Amperometric sensor for L-ascorbic acid determination based on MnO 2 bulk modified screen printed electrode

2000 ◽  
Vol 368 (5) ◽  
pp. 466-470 ◽  
Author(s):  
E. Turkusic ◽  
V. Milicevic ◽  
H. Tahmiscija ◽  
M. Vehabovic ◽  
S. Basic ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Amperometric Sensor ◽  
Screen Printed Electrode ◽  
Ascorbic Acid Determination ◽  
Acid Determination ◽  
Screen Printed
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