Biomaterial Database

Flow injection system with chemiluminometric detection for enzymatic determination of ascorbic acid. 2000

A F Dãnet, and M Badea, and H Y Aboul-Enein

University of Bucharest, Faculty of Chemistry, PO Box 164, Bucharest 15, Romania.

A simple, selective and rapid method for determination of ascorbic acid from fruit juices was developed by combining a flow injection analysis (FIA) system with a chemiluminometric detector and a reactor with L-ascorbate oxidase immobilized on controlled pore glass. It was found that some reducing agents (eg ascorbic acid and mercaptoacetic acid) give chemiluminescence with luminol in the presence of hexacyanoferrate (III) in an alkaline solution. We used this new type of chemiluminescent reaction for the enzymatic determination of ascorbic acid. The background substraction method was used in order to avoid interference during ascorbic acid determination. Accordingly, two chemiluminometric signals were registered for each determination, one signal corresponding to the sample that passed through the enzymatic reactor that decomposed the ascorbic acid completely, and the second signal corresponding to the sample that does not pass through the reactor. The difference between the two signals corresponds to ascorbic acid from the sample. The linear range of the method was 10-1000 micromol/L of ascorbic acid and the detection limit was 5 micromol/L The throughput was four samples/h and RSD 3.13% (n = 10). This method was applied for determination of ascorbic in fruit juices. The results were compared with those found by the reference method, based on titrimetric determination with 2,6-dichlorophenolindophenol, and the concordance was excellent.

UI	MeSH Term	Description	Entries
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D008163	Luminescent Measurements	Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.	Bioluminescence Measurements,Bioluminescent Assays,Bioluminescent Measurements,Chemiluminescence Measurements,Chemiluminescent Assays,Chemiluminescent Measurements,Chemoluminescence Measurements,Luminescence Measurements,Luminescent Assays,Luminescent Techniques,Phosphorescence Measurements,Phosphorescent Assays,Phosphorescent Measurements,Assay, Bioluminescent,Assay, Chemiluminescent,Assay, Luminescent,Assay, Phosphorescent,Assays, Bioluminescent,Assays, Chemiluminescent,Assays, Luminescent,Assays, Phosphorescent,Bioluminescence Measurement,Bioluminescent Assay,Bioluminescent Measurement,Chemiluminescence Measurement,Chemiluminescent Assay,Chemiluminescent Measurement,Chemoluminescence Measurement,Luminescence Measurement,Luminescent Assay,Luminescent Measurement,Luminescent Technique,Measurement, Bioluminescence,Measurement, Bioluminescent,Measurement, Chemiluminescence,Measurement, Chemiluminescent,Measurement, Chemoluminescence,Measurement, Luminescence,Measurement, Luminescent,Measurement, Phosphorescence,Measurement, Phosphorescent,Measurements, Bioluminescence,Measurements, Bioluminescent,Measurements, Chemiluminescence,Measurements, Chemiluminescent,Measurements, Chemoluminescence,Measurements, Luminescence,Measurements, Luminescent,Measurements, Phosphorescence,Measurements, Phosphorescent,Phosphorescence Measurement,Phosphorescent Assay,Phosphorescent Measurement,Technique, Luminescent,Techniques, Luminescent
D008165	Luminol	5-Amino-2,3-dihydro-1,4-phthalazinedione. Substance that emits light on oxidation. It is used in chemical determinations.
D002957	Citrus	A plant genus of the family RUTACEAE. They bear the familiar citrus fruits including oranges, grapefruit, lemons, and limes. There are many hybrids which makes the nomenclature confusing.	Citron Tree,Fruit, Citrus,Lemon Tree,Orange Tree, Bitter,Orange Tree, Mandarin,Orange Tree, Seville,Orange Tree, Sour,Pomelo Tree,Pummelo Tree,Tangerine Tree,Citrus Fruit,Citrus aurantium,Citrus bergamia,Citrus grandis,Citrus hystrix,Citrus limon,Citrus maxima,Citrus medica,Citrus reticulata,Kaffir Lime,Bitter Orange Tree,Bitter Orange Trees,Citron Trees,Citrus aurantiums,Citrus bergamias,Citrus grandi,Citrus hystrices,Citrus medicas,Citrus reticulatas,Lemon Trees,Lime, Kaffir,Mandarin Orange Tree,Mandarin Orange Trees,Orange Trees, Bitter,Orange Trees, Mandarin,Orange Trees, Seville,Orange Trees, Sour,Pomelo Trees,Pummelo Trees,Seville Orange Tree,Seville Orange Trees,Sour Orange Tree,Sour Orange Trees,Tangerine Trees,Tree, Bitter Orange,Tree, Citron,Tree, Lemon,Tree, Mandarin Orange,Tree, Pomelo,Tree, Pummelo,Tree, Seville Orange,Tree, Sour Orange,Tree, Tangerine,Trees, Bitter Orange,Trees, Citron,Trees, Lemon,Trees, Mandarin Orange,Trees, Pomelo,Trees, Pummelo,Trees, Seville Orange,Trees, Sour Orange,Trees, Tangerine,aurantium, Citrus,bergamia, Citrus,hystrices, Citrus,maxima, Citrus,medicas, Citrus,reticulata, Citrus
D004800	Enzymes, Immobilized	Enzymes which are immobilized on or in a variety of water-soluble or water-insoluble matrices with little or no loss of their catalytic activity. Since they can be reused continuously, immobilized enzymes have found wide application in the industrial, medical and research fields.	Immobilized Enzymes,Enzyme, Immobilized,Immobilized Enzyme
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D005292	Ferricyanides	Inorganic salts of the hypothetical acid, H3Fe(CN)6.
D005638	Fruit	The fleshy or dry ripened ovary of a plant, enclosing the seed or seeds.	Berries,Legume Pod,Plant Aril,Plant Capsule,Aril, Plant,Arils, Plant,Berry,Capsule, Plant,Capsules, Plant,Fruits,Legume Pods,Plant Arils,Plant Capsules,Pod, Legume,Pods, Legume
D001204	Ascorbate Oxidase	An enzyme that converts ascorbic acid to dehydroascorbic acid. EC 1.10.3.3.	Ascorbase,Ascorbino Dehydrogenase,L-Ascorbate Oxidase,Dehydrogenase, Ascorbino,L Ascorbate Oxidase,Oxidase, Ascorbate,Oxidase, L-Ascorbate
D001628	Beverages	Liquids that are suitable for drinking. (From Merriam Webster Collegiate Dictionary, 10th ed)	Beverage