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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Soft drink Coca cola

Classification: Beverage -> non alcoholic -> soft drink -> coca cola

Citations 3

"Flow Injection Analysis With A Fluorimetric Detector For Determinations Of Glycine And Albumin"
Anal. Chim. Acta 1979 Volume 106, Issue 2 Pages 395-399
Joy I. Braithwaite and J. N. Miller

Abstract: Flow injection analysis with fluorometric detection was used in the determination of glycine and albumin, with o-phthalaldehyde being used in determination of the latter. Preliminary variables and applications of flow injection analysis were examined, using quinine sulfate and m-hydroxybenzoic acid which are intrinsically fluorescent. System response was linear in the range of 0-8 µg/mL for glycine and concentrations as low as 2 pg/mL were detectable. The level of glycine in orange juice and dietetic cola was 0.33-0.41 and 0.17 g/dL, respectively. Serum albumin determinations flow injection analysis had a relative standard deviation of 1.8%. The method allowed sampling rates of 180/h for both glycine and albumin.
Glycine Albumin Clinical analysis Fluorescence Optimization

"Flow Injection Potentiometric Determination Of Coke Acidity And Acetic Acid Content In Vinegar Using An Antimony Electrode"
Anal. Lett. 1996 Volume 29, Issue 5 Pages 711-724
Capelato, M.D.;Marli Dos Santos, A.;Fatibello, O.;Gama, R.

Abstract: An Sb/Sb2O3 electrode was used to measure the acidity of coke and vinegar samples by FIA. Sample (50 µL) was injected into a carrier solution of 0.1 M NaNO3 of pH 6.5 (2 ml/min) via a flow manifold (schematic given). Phosphate buffer solutions were used as pH standards. Solutions passed through a 50 cm helicoidal tubular reactor and on to a potentiometric detector cell comprising a circular plane Sb indicator electrode and a Ag/AgCl/0.1 M NaCl, 3 M NaNO3 as reference electrode. A linear response to acidity was achieved for 3.16-100 mM acetic acid with a slope of 30.1 mV/decade and a sample throughput of 23 samples/h. The average standard deviation was ±0.5%. The method should be suitable for routine analyzes.
Acetic acid pH Potentiometry Electrode Reactor

"Sequential Injection Spectrophotometric Determination Of Orthophosphate In Beverages, Wastewaters And Urine Samples By Electrogeneration Of Molybdenum Blue Using Tubular Flow-through Electrodes"
Anal. Chim. Acta 2004 Volume 510, Issue 1 Pages 61-68
Francisca Mas-Torres, José Manuel Estela, Manuel Miró, Andreu Cladera and Víctor Cerdà

Abstract: A novel and automated sequential injection procedure is proposed for the spectrophotometric determination of orthophosphate without requiring unstable chemical reducing species used in the classical molybdenum blue method. The flowing methodology is based on the on-line generation of the detectable species by electrochemical reduction of the 12-molybdophosphoric acid complex using a stainless steel tubular flow-through working electrode. The established method is linear up to 20 mg/l P, with coefficients of variation (n=10) of 2.4 and 1.8% for 2.0 and 10 mg/l P, respectively. The versatility of the sequential injection method to analyze samples containing high orthophosphate levels has been demonstrated by the implementation of a dilution chamber as well as flow-reversal techniques, yielding relative standard deviations (n=17) better than 2.0% for standards containing 200 and 800 mg/l P. The proposed analyzer. features an extremely wide dynamic range (viz., 0.3-800 mg/l) as well as improved tolerance to silicate interference, so that Si/P ratios higher than 50 are tolerated at the 5% level. Electrochemical conditions, reagent concentrations and physical variables have been thoroughly investigated. The method has been applied to the determination of orthophosphate in wastewaters as well as beverages and biological samples containing high concentrations of the target analyte. The t-test comparison of the means for the developed sequential injection system with electroreduction and both the molybdenum blue classical spectrophotometric batch procedure and inductively coupled plasma-optical emission spectrometric detection selected as external reference methods revealed that there is no evidence of significant differences between the obtained results at the 95% confidence level.
Phosphate Spectrophotometry Sequential injection Method comparison Interferences Flow reversal Gradient technique Mixing chamber Electrochemical reagent generation