University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Beverage -> non alcoholic

Citations 5

"Potentiometric-stripping Analysis Of Lead And Tin With A Continuous-flow System"
Analyst 1984 Volume 109, Issue 7 Pages 905-907
Saverio Mannino

Abstract: The flow cell is as used by Anderson et al. (cf. Anal. Abstr., 1983, 44, 2J123) and contains mercury-film (on vitreous carbon, prepared in situ) working and counter-electrodes and a silver - AgCl reference electrode. The sample is pumped through the cell at a constant rate and electrolysis is carried out for an appropriate time at -1.2 V. Then de-aerated ammonium citrate buffer solution (pH 4.6) containing 10 ppm of Hg(II) is passed through the cell for 30 s, the flow is stopped and the potentiometric-stripping curve is recorded. Quantitation is by the method of standard additions. The method was applied to eight samples of fruit juices or soft drinks, and results agreed with those by AAS (for Pb) or anodic-stripping voltammetry (for Sn). The proposed method can be used to determine 0.1 ppb of Sn and Pb.
Tin Lead Electrode Potentiometric stripping analysis Method comparison Simultaneous analysis Standard additions calibration

"Flow Injection Extraction In Theory And Practice"
Fresenius J. Anal. Chem. 1988 Volume 329, Issue 6 Pages 660-662
Bo Karlberg

Abstract: Flow injection schemes involving solvent extraction are reviewed, with examples. Procedures are given for the extractions of caffeine from beverages, anionic surfactants from aqueous samples, codeine from drugs, bitterness compounds from beer, and phenol from water. The organic extractant is 2,2,4-trimethylpentane (for beer) or CHCl3 (others). A typical system is characterized by low comsumption of organic phase (0.5 to 2 mL per sample), low sample volume (20 to 200 µL) and high sample throughput (45 to 120 h-1). (9 references).
Bittering compounds Caffeine Codeine Phenol Surfactants, anionic Sample preparation Extraction Review Tecator Theory

"Applications Of Immobilized Enzymes In Flow Injection Analysis"
Anal. Proc. 1985 Volume 22, Issue 1 Pages 6-8
Stephen, M. Masoom, Alan Townshend

Abstract: Samples of blood serum and soft drinks were injected into a stream of phosphate buffer solution (pH 7) which then passed through a glass column (2.5 cm x 2.5 mm) containing glucose oxidase (immobilized on controlled-pore glass) to a flow-through amperometric detector for the determination of H2O2. Sucrose in soft drinks was determined by use of immobilized β-D-fructofuranosidase, aldose 1-epimerase and glucose oxidase. The limit of detection was 1 µM-H2O2.
Glucose Sucrose Amperometry Immobilized enzyme Controlled pore glass

"Determination Of Vitamin C By FIA With Reversed Merging Zone"
Fenxi Shiyanshi 1996 Volume 15, Issue 2 Pages 34-36
Huang, Y.S.;Fang, Q.;Huang, J.;Sun, Y.Q.

Abstract: Sample (60-150 µL) was injected into the flow injection manifold (schematic illustrated) and transported by a carrier stream of 0.75 M acetic acid to a merging reactor (1.5 m x 0.5 mm i.d.) and mixed with a reagent stream of 84 µM-KIO3/0.2 M KI. The excess I3- generated by the reaction was detected at 350 nm. The calibration graph was linear up to 50 µM-vitamin C (ascorbic acid; I). Only starch (50 µg), 10 µg Cu(II) and 10 µg Fe(III) interfered. The method was applied to the analysis of canned lychee drinks, fruit cocktail, and I sugar-coated pills, with recoveries of 98.7-99.8% and RSD (n = 5) of 0.5-1.7%.
Ascorbic acid Spectrophotometry Interferences Merging zones

"Removal Of Ascorbic Acid Interference In The Determination Of Glucose And Sucrose In Non-alcoholic Beverages"
Food Chem. 1993 Volume 48, Issue 1 Pages 95-98
S. M. Tzouwara-Karayanni*, M. I. Karayannis* and S. R. Crouch*

Abstract: With use of a computer-controlled flow injection system, one portion of the degassed or (for natural orange juice) centrifuged sample was diluted with 0.05 M phosphate buffer of pH 6.86 and injected into the same buffer as carrier. The stream was passed through a single-bead string reactor containing glucose oxidase immobilized on glass beads and then mixed with Trinder reagent (containing 0.8 mg/ml of peroxidase, 1 mM 4-aminoantipyrine and 1 mM 3,5-dichloro-2-hydroxybenzenesulfonic acid). The absorbance of the product was recorded at 510 nm. A second portion of sample was treated with invertase (β-fructofuranosidase) and analyzed similarly to determine sucrose. A third portion was treated with invertase and made 40 µm in ascorbic acid (I) before analysis to determine the contribution of I. A fourth portion was treated with invertase, I and ascorbase (L-ascorbate oxidase) to remove the ascorbic acid and also to invert sucrose. Application of a standard addition method for glucose indicated recoveries in the range 99.1-102.7%, and the RSD (n = 6) for 1.1 mM glucose was 3%.
Glucose Sucrose Spectrophotometry Interferences Glass beads