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

Citations 27

"Evaluation Of The Terbium(III)-sensitized Luminescence With Benzenepolycarboxylic Acids. Determination Of Terephthalic Acid In Drink Samples"
Anal. Chim. Acta 2000 Volume 407, Issue 1-2 Pages 53-60
M. A. Caro de la Torre and A. Gómez-Hens

Abstract: The reaction of terbium(III) with several benzenepolycarboxylic acids, viz. phthalic, isophthalic, terephthalic, hemimellitic, trimellitic and trimesic acids, was systematically studied in order to determine the effect of the geometry of these compounds on the luminescence intensity obtained. This study showed that terephthalic acid gave a very high luminescence signal with terbium(III) in the presence of trioctylphosphine oxide as synergistic agent and Triton X-100 as micellar medium, and by using the time-resolved mode. The system was used for the development of a very sensitive and fast method for the determination of terephthalic acid, which can be applied to migration studies of this compound released to drinks stored in plastic bottles of polyethylene terephthalate. Initial rate and equilibrium signal measurements were obtained in only 0.2 and 2 s, respectively, by using the stopped-flow mixing technique, although the features of the kinetic method were better than those of the equilibrium method. The calibration graph of the kinetic method was linear over the range 0.01-3.0 mg mL-1 and the detection limit was s ng mL-1. The relative standard deviation was close to 2%. The analytical recoveries obtained by applying the method to the analysis of drink samples ranged from 92.5 to 107.0%. The method can be extended to the determination of terephthalic acid esters, such as dimethyl terephthalate, after their alkaline hydrolysis.
Terephthalic acid Chemiluminescence Micelle Triton X Kinetic Stopped-flow

"Flow Electrochemical Determination Of Ascorbic Acid In Real Samples Using A Glassy Carbon Electrode Modified With A Cellulose Acetate Film Bearing 2,6-dichlorophenolindophenol"
Anal. Chim. Acta 2000 Volume 409, Issue 1-2 Pages 113-121
Ageliki B. Florou, Mamas I. Prodromidis, Miltiades I. Karayannis and Stella M. Tzouwara-Karayanni

Abstract: An ascorbate sensor based on a glassy carbon electrode modified with a cellulose acetate polymeric film bearing 2,6-dichlorophenolindophenol (CA/DCPI-CME) was constructed. The overall reaction obeys a catalytic regeneration mechanism (EC mechanism) and the electrochemical rate constant kf for the electrocatalytic oxidation of ascorbic acid was evaluated. The modified electrodes were mounted in a flow injection (FI) manifold, poised at +100 mV versus Ag/AgCl/3 M KCl at pH 6.5 and utilized for the determination of ascorbic acid in beverages and pharmaceuticals. Good correlation with a reference method was attained. Interferents of various molecular sizes were tested. Calibration graphs were linear over the range 0.02-1 and 0.1-6 mM ascorbic acid for CA/DCPI sensors hydrolyzed in KOH and ZnCl2 solution, respectively. The throughput was 25 samples per hour and the CV was for a 0.4 mM ascorbic acid solution 0.75 (n=14) and 1.2% (n=10) for CA/DCPI sensors hydrolyzed in KOH and ZnCl2 solution, respectively. The recovery was 92-110%. The sensors showed very good repeatability and operational stability.
Ascorbic acid Electrode Electrode Method comparison Interferences

"Preconcentration And Differential Pulse Voltammetry Of Butylated Hydroxyanisole At A Carbon Paste Electrode"
Anal. Chim. Acta 1983 Volume 154, Issue 1 Pages 87-94
Joseph Wang and Bassama A. Freiha

Abstract: Butylated hydroxyanisole (I) and tocopherols were pre-concentrated by accumulation on carbon-paste electrodes (2.5 g of Acheson graphite, grade 38, plus 1.5 g of Dow Corning silicone grease). After pre-concentration for 5 min, a detection limit of ~20 µM-I was obtained. Enhanced selectivity was achieved by transferring the electrode to an electrolytic blank solution before the measurement step; this enabled the surface-bound species to be measured without interference from species in solution The differential pulse stripping response was evaluated with respect to concentration. dependence, reproducibility, pre-concentration period, detection limit and other variables. The cited method was used in the selective detection of I in a flow injection system based on a recently developed manifold procedure (Anal. Chem., 1983, 55, 1285). The method was applied to, e.g., soft drinks, maize oil and multivitamin tablets.
Butylated hydroxyanisole Tocopherols Electrode Voltammetry Interferences Preconcentration

"Fluoride Ion-selective Electrode In Flow Injection Analysis. 3. Applications"
Anal. Chim. Acta 1986 Volume 188, Issue 1 Pages 151-164
Wolfgang Frenzel and Peter Brätter

Abstract: Optimum conditions are described for the determination of trace amounts of F- in tap water, beverages and urine by flow injection potentiometry with a F--selective electrode. Good sensitivity (1 µg l-1) and long-term stability were obtained, with a sample throughput of 30 to 40 h-1, based on triplicate injections at 120 h-1. Total ionic strength adjustment buffer (TISAB-III) was unsuitable for the analysis of undiluted tea and urine. Such samples with high inherent I and large amounts of interfering elements required a modified citrate-containing TISAB buffer. Recoveries of 0.01 to 1 mg L-1 of F- added to tap water, tea and urine were 91 to 106%. The apparatus allowed rapid changes between buffers and carrier streams.
Fluoride Electrode Potentiometry Interferences

"Determination Of L-alanine In A Flow Injection System With An Immobilized Enzyme Reactor"
Anal. Chim. Acta 1990 Volume 239, Issue 2 Pages 307-310
Nobutoshi Kiba, Hirohisa Tagami and Motohisa Furusawa

Abstract: The sample was injected into a merged stream of 15 mM NAD+ and 0.2 M glycine - NaCl - NaOH buffer, pH 10.3, at 0.8 mL min-1, which flowed into a reactor of alanine dehydrogenase immobilized on poly(vinyl alcohol) beads at 40°C. The fluoresence of the NADH produced was measured at 465 nm (excitation at 340 nm). The response was rectilinear from 0.5 to 500 µM, with a limit of detection of 0.2 µM and a coefficient of variation (n = 9) of 0.9% for 100 µM. The coefficient (n = 5) for serum and beverages were between 1% for 0.02 to 410 µM.
l-Alanine Fluorescence Immobilized enzyme Buffer Detection limit

"Automatic Implementation Of The Method Of Standard Additions In Unsegmented Flow Systems"
Anal. Chim. Acta 1995 Volume 308, Issue 1-3 Pages 77-84
Manuel Agudo, Angel Ríos and Miguel Valcárcel*

Abstract: A flow system was described for the preparation of sample and standard solutions for calibration by the method of standard additions. The system allowed variable volumes of both sample and standard solution added to a carrier. After homogenizing, a portion was injected into the FIA manifold for analysis. The methodology was applied to the determination of glucose and fructose in various types of drinks using various immobilized enzymes. The combined concentration of glucose and fructose was obtained by reaction with adenosine-5-triphosphate and β-NADP+ in the presence of the immobilized enzymes hexokinase, phosphoglucose isomerase (PGI) and glucose-6-phosphate dihydrogenase. The NADPH formed was monitored at 340 nm. Glucose was determined by omitting PGI from the enzyme column which enable fructose to be calculated by difference. Glucose and fructose were determined in the ranges 0.01-0.1 g/l and 0.02-0.1 g/l, respectively, and the RSD was ±0.8% for 0.05 g/l glucose and ±1% for 0.07 g/l fructose. The analysis of drinks yielded average errors of 3.8% for glucose and 4.6% for fructose.
Fructose Glucose Spectrophotometry Column Immobilized enzyme Standard additions calibration

"Glucose Oxidase Polyion Complex-bilayer Membrane For Elimination Of Electroactive Interferents In Amperometric Glucose Sensor"
Anal. Chim. Acta 1998 Volume 364, Issue 1-3 Pages 173-179
Fumio Mizutani*, Yukari Sato, Yoshiki Hirata, Takahiro Sawaguchi and Soichi Yabuki

Abstract: An amperometric glucose-sensing electrode was prepared by immobilizing glucose oxidase (GOx) on a polyion complex membrane. First, a monolayer of 3-mercaptopropionic acid (MPA) was made on the surface of a gold electrode by immersing it in an ethanol solution containing MPA. Aqueous solutions of poly-L-lysine and poly-4-styrenesulfonate were successively placed on the electrode surface and allowed to dry. A GOx layer was then formed on the poly-L-lysine/poly-4-styrenesulfonate-complex layer by crosslinking the enzyme by the addition of a glutaraldehyde solution. The polyion complex layer was effective for eliminating electrochemical interferents such as L-ascorbic acid, uric acid and acetaminophen. whereas the hydrogen peroxide produced through the GOx-catalyzed reaction permeated rapidly through the layer. This resulted in a rapid response (100% response in <5 s) with a low interference level (e.g., the ratio of response for L-ascorbic acid to that for the same concentration of glucose was 0.07). The electrode was applied to the assay of glucose in beverages and sera, and could be used for more than two months,
Glucose Amperometry Electrode Electrode Electrode Interferences Apparatus Detector

"Flow Injection Spectrophotometric Determination Of Citric Acid In Beverages Based On A Photochemical Reaction"
Anal. Chim. Acta 1998 Volume 366, Issue 1-3 Pages 231-240
Encarnaci&oacute;n Luque-P&eacute;rez, Angel R&iacute;os and Miguel Valc&aacute;rcel*

Abstract: A photochem. method for the determination of citric acid in beverages using a flow injection system is proposed. The basis for the determination is the reaction that takes place between citric acid and Fe3+ upon irradn. with visible or UV light. Fe3+ is photochem. reduced by citric acid to Fe2+, which reacts with 1,10-phenanthroline, forming the reddish orange Fe(phen)2+3 complex. This complex (ferroin) is spectrophotometrically monitored at 512 nm, and the signal is directly related to the concentration. of citric acid in the sample. The method shows a linear range between 1 and 120 µg mL-1, with a relative standard deviation of 2.8% and a sample throughput of 40 samples h-1.
Citric acid Spectrophotometry Photochemistry UV reactor Complexation Indirect

"Flow Injection Stopped-flow Kinetic Spectrophotometric Determination Of Drugs, Based On Micellar-catalysed Reaction With 1-fluoro-2,4-dinitrobenzene"
Talanta 1991 Volume 38, Issue 7 Pages 689-696
Constantinos A. Georgiou, Michael A. Koupparis* and Themistocles P. Hadjiioannou,

Abstract: Dihydralazine (I), isoniazid (II), levodopa (III) and aspartame (IV) are determined in a flow injection system in which a solution of 8.40 mM 1-fluoro-2,4-dintrobenzene in aqueous 20% ethanol acidified with 1 mM HCl was pre-mixed with 0.10 M borate buffer (pH 9.5) containing hexadecyltrimethyl-ammonium bromide (3.5 mM for I and II, 1.5 mM for III and IV) before merging with the aqueous injected sample stream. After mixing, the reaction mixture flow was stopped for 16 s followed by 2 s of mixture equilibration before multiple (40 to 256) absorbance measurements were recorded during 15 to 40 s at 428 nm for I and II and 340 and 342 nm for III and IV, respectively. The calibration graphs were rectilinear from 0.01 to 0.2 mM (III) and from 0.05, 0.01 and 0.06 to 0.6 mM (I, II and IV, respectively), and the respective detection limits were 18, 0.9, 6.3 and 20 µM for I, II, III and IV. The method, which may also be used to determine several other drugs which form soluble derivatives with the reagent, was used to determine II, III and IV in pharmaceutical formulations, II in formulations containing rifamycin, and IV in colored beverages. The results agreed well with those of reference methods.
Drugs Spectrophotometry Buffer Catalysis Detection limit Kinetic Micelle Stopped-flow Method comparison

"Potentiometric Determination Of Fluoride By A Combination Of Continuous-flow Analysis And The Gran Addition Method"
Analyst 1981 Volume 106, Issue 1269 Pages 1275-1280
J.-Cl. Landry, F. Cupelin and C. Michal

Abstract: method is described for the determination of fluoride ion by continuous-flow analysis combined with the Gran addition method using an ion-selective electrode.The Gran addition method is a reliable potentiometric technique and an advantage of its use is that, in addition to the determination of the free and total fluoride concentration in a complexed medium, the complexation rate is also measured. The drawback of the method is the difficulty in adjusting the peristaltic pumps, which is time consuming. However, this extra time is compensated for by the simultaneous determination of fluoride ion concentration and the complexation rate.For concentrations of fluoride ion between 0.5 and 100 mg 1-1, the precision is 5%.
Fluoride Potentiometry

"Bioluminescent Flow-sensing Device For The Determination Of Magnesium(II)"
Analyst 1993 Volume 118, Issue 7 Pages 849-853
Stefano Girotti, Elida Ferri, Severino Ghini, Pavel Rauch, Giacomo Carrea, Roberto Bovara, Aldo Roda, Maria Antonietta Giosu&eagrave;, Piero Masotti and Gianni Gangemi

Abstract: A continuous-flow system was developed for the determination of magnesium in serum, drugs and beverages. The system used firefly luciferase (LUC) or recombinant luciferase (r-LUC) from Escherichia coli (1 mg/ml) immobilized on a nylon coil activated with triethyloxonium tetrafluoroborate, 1,6-diaminohexane and glutaraldehyde or immobilized on a column of epoxy methacrylate (Eupergit) placed inside a luminometer. The bioluminescence continuous-flow assay manifold for the nylon coil system involved two streams. The first supplied the coil with the working bioluminescent solution and the second was a continuous-flow of air into which a known volume (5-20 µL) of sample was injected. The same system was used for the Eupergit column except that the air was replaced with Tris acetate buffer. The optimal conditions were 0.05 mM luciferin and 0.3 mM ATP at a flow rate of 0.4 ml/min for an LUC-Eupergit column or an r-LUC-nylon coil; the corresponding responses were linear for 0.05-6.7 and for 0.01-6.7 mM Mg. Both the intra- and inter-assay RSD were 7%. There was no interference from Ca(II), Mn(II), Fe(II), Cu(II), Zn(II), or Co(II).
Magnesium(II) Bioluminescence Interferences

"Atomic Spectrometry Update: Clinical And Biological Materials, Foods And Beverages"
J. Anal. At. Spectrom. 1991 Volume 6, Issue 3 Pages 69R-107R
Simon Branch, Helen M. Crews, David J. Halls and Andrew Taylor

Abstract: This Update contains reviews on recent developments in the application of atomic spectrometry to the analysis of clinical and biological materials and of foods and beverages. These two reviews cover the references 90/1159-90/4166 and 91/1-91/825 which are listed fully as Atomic Spectrometry Update References in Volumes 5 and 6 of JAAS, respectively. A list of references to published papers in abbreviated form appears at the end of this Update. The Tables, in an improved format, summarise the methods and studies covered in these reviews. Last year's Update (J. Anal. Atomic Spectrom., 1990, 5, 75R) covered developments in the preceding year.
Fluorescence Mass spectrometry Spectrophotometry Voltammetry Clinical analysis Review Supercritical fluid Reference material Principal component analysis

"Determination Of Salicylate In Beverages And Cosmetics By Use Of An Amperometric Biosensor"
Fresenius J. Anal. Chem. 1996 Volume 356, Issue 1 Pages 75-79
M. Ehrendorfer, G. Sontag Contact Information and F. Pittner

Abstract: A fast and selective enzymatic method for the determination of sialicylate in beverages and cosmetics has been developed. The enzyme salicylate hydroxylase was immobilized covalently onto a glassy carbon working electrode of a wall-jet cell coupled with a flow injection analysis system. The salicylate is enzymatically converted to catechol, which can be detected amperometrically on the glassy carbon electrode at +0.45 V. The response of the biosensor is linearly proportional to the concentration of salicylate between 725 nmol/l and 700 µmol/l. A high sample throughput (60 h-1) is possible, and the biosensor is stable for more than three months. Sample pretreatment for beverages and hair lotions is easy and fast. For creams, an extraction of salicylate is necessary. Relative standard deviations are less than 5.5% and the recoveries are between 9 and 105%.
Salicylate Amperometry Sensor Electrode Electrode Enzyme

"Biocatalysis And Biorecognition In Nonaqueous Media. Some Perspectives In Analytical Biochemistry"
Microchim. Acta 1995 Volume 120, Issue 1-4 Pages 231-242
Lorenzo Braco

Abstract: A review is presented. The basic principles and advantages of non-aqueous enzymology are outlined and its analytical applications are discussed with reference to batch analysis in organic media, flow injection enzyme reactors operating in organic media, organic-phase enzyme electrodes and enzyme-based gas-phase biosensors. Analytical applications of antibodies and abzymes in non-aqueous media are discussed and the potential of molecular imprinting techniques to generate specific recognition systems is considered. (56 references). Biocatalysis and, to a lesser extent, biorecognition in non-aqueous media (including organic solvents as well as supercritical fluids and gases) constitute at present an exciting research area which has already demonstrated its biotechnological potential in numerous, varied applications. Less attention, however, has been paid to its analytical possibilities, even though many advantages have been postulated and a wide range of poorly water-soluble analytes are present in samples (or waste materials) from food and drink, petrochemical, pharmaceutical, military and other industries. The main approaches, developed in recent years to exploit the use of enzymes, antibodies or antibody mimics in water-restricted environments for analytical purposes, as well as possible future directions are briefly discussed.
Sensor Immobilized enzyme Reverse micelle Review Catalysis

"New Approaches To Coupling Flow Injection Analysis And High Performance Liquid Chromatography"
J. Chromatogr. A 1992 Volume 600, Issue 2 Pages 183-188
M. D. Luque de Castro* and M. Valc&aacute;rcel

Abstract: In pre-column arrangements (A), the flow injection system is placed before the LC column, whilst in post-column couplings (B), the chromatographic process takes place before the flow injection analysis. In each instance the downstream unit incorporates the detection module. Examples of the use of A include: the determination of Zn based on its activating effect on metal-free carboxypeptidase A immobilized in a controlled-pore-glass reactor; the coupling of a liquid - liquid extractor to a normal-phase chromatograph for the determination of caffeine in beverages and urine; and the coupling of an ultrasonic leaching cell for solid - liquid extraction processes such as in the determination of B in soil. Only those B systems incorporating two valves are considered to be true HPLC - flow injection analysis configurations. Examples of the use of B include: determination of aflatoxins in foodstuffs, based on enhancing their fluorescence by means of a redox reaction with Br; and the determination of bile acids, based on the production of NADH. A review with 15 references. An overview of the advantages gained in coupling a flow injection manifold to a liquid chromatograph is presented. Improvements in the analytical features arising from this association and the peculiar pre- and post-column arrangements are discussed, as are the promising prospects of arrangements to be developed for avoiding the preliminary steps of the analytical process.
Caffeine HPLC Post-column derivatization Pre-column derivatization Immobilized enzyme Controlled pore glass Review

"Enzymic Assays Using Flow Injection Analysis"
Anal. Proc. 1983 Volume 20, Issue 9 Pages 486-486
P. J. Worsfold and Julian F. Tyson

Abstract: Dr. P. J . Worsfold (Sheffield City Polytechnic) described how certain ancillary FIA techniques could be applied to enzymatic assays. The use of the stopped-flow technique for the determination of alcohol in blood and beverages and the use of a dialysis unit and an on-line immobilized enzyme for the determination of blood glucose were discussed in detail.
Ethanol Glucose Spectrophotometry Dialysis Stopped-flow Enzyme

"Potential Of Flow Injection Methodology For Beverage Analysis"
Am. J. Enol. Vitic. 1992 Volume 43, Issue 1 Pages 93-100
M. D. Luque De Castro and J. A. Garc&iacute;a-Mesa

Abstract: A literature review of the use of flow injection analysis for the analysis of beverages (particularly wines) is presented. The different possibilities of carrying out individual and multiple determinations (whether simultaneous or sequential) with or without the aid of continuous on- line separation are critically discussed.
Review Method comparison Sequential injection Simultaneous analysis

"Biosensing Of Glucose, Sucrose, And Lactate In Beverages With An Automated Multi-channel Flow Analyzer"
Biosci. Biotechnol. Biochem. 1995 Volume 59, Issue 5 Pages 813-816
Chen, R.L.C.;Matsumoto, K.

Abstract: A multi-channel continuous-flow analyzer equipped with biosensing devices was developed for multicomponent measurement and its use in automating routine analysis was evaluated. Biosensing was achieved by the aid of an immobilized enzyme reactor installed in the channel, and the channel switching process for the sensing of a different compound was made by using a column-switching rotary valve. Another rotary valve was used for auto-sampling. Both of the two rotary valves were interfaced to a system controller and work conjugatively in a programmed manner. Signal subtraction between different channels was found to be more precise compared with the multi-channel flow injection analysis method, which is of merit for an analysis utilizing enzyme relay reaction (as for sucrose analysis) or for background signal subtraction. Glucose, lactate, and sucrose content in real samples were measured automatically with high reproducibility, and the results agree well with the kit method.
Glucose Sucrose Lactate Immobilized enzyme Valve Multichannel

"Flow Injection Analysis For Glucose Using An Amperometric Enzyme Electrode Based On Lipid-modified Glucose Oxidase As The Detector"
Biosens. Bioelectron. 1994 Volume 9, Issue 6 Pages 411-414
Fumio Mizutani* and Soichi Yabuki

Abstract: The enzyme sensor was prepared by coating a vitreous-carbon electrode with lipid-modified glucose oxidase applied in benzene solution, and then coating with Nafion. The electrode was used in a flow injection system with 0.1 M potassium phosphate buffer of pH 7 as carrier solution and was operated at a potential of 0.9 V vs. Ag/AgCl. The response to glucose was rapid (2 s) and the calibration graphs were linear up to 10 mM glucose. The electrode was stable for 12 weeks after 2000 glucose injections. The detection limit was 50 µM-glucose. Glucose could be determined in serum and fruit juices or drinks with 1% interference from ascorbic acid; uric acid interfered in the analysis of serum.
Glucose Electrode Electrode Sensor Amperometry Interferences

"Comparison Of Post-column Fluorescence Derivatization And Evaporative Light-scattering Detection To Analyse Saccharides Selectively By LC"
Chromatographia 1992 Volume 34, Issue 11-12 Pages 651-654
A. Coquet, J. -L. Veuthey and W. Haerdi

Abstract: Portions (10 µL) of 50 mM lactose, glucose or fructose were analyzed by LC on a column (30 cm x 6.5 mm) packed with an ion exchange resin (Ca2+ form) and operated at 70°C with water as mobile phase (0.4 mL min-1) and post-column reaction with 30 mM benzamidine and 1 M KOH at 100°C for fluorimetric detection at 470 nm (excitation at 360 nm). The method was not suitable for non-reducing sugars. Results were compared with those obtained by use of an evaporative light-scattering detection system. A broader range of linearity was observed with the former method (i.e., 16 µM to 5 mM) than with the latter (6.25 mM to 50 mM). The method was applied for the analysis of reducing sugars in beverages.
Saccharides Lactose Glucose Fructose HPIC Fluorescence Post-column derivatization Heated reaction Method comparison

"Spectrophotometric Determination Of Ascorbic Acid In Vitamin C Tablets, Beverages, Orange And Urine With 2,6-dichloroindophenol By Flow Injection Analysis"
Fenxi Huaxue 1991 Volume 19, Issue 2 Pages 182-184
Ma, H.C.;Feng, J.Z.;Cao, B.

Abstract: Sample is injected into a carrier stream of potassium hydrogen phthalate buffer of pH 3.6 (2 mL min-1) for reaction with a reagent stream of 0.2 mM dichloroindophenol (1.5 mL min-1) in a 15-cm reaction coil before kinetic spectrophotometric detection at 525 nm. For the analysis of vitamin C tablets, oranges, beverages and urine by use of the standard-additions method, recovery was 72 to 117%. For 50 µg mL-1 of I, the coefficient of variation was 0.5%. Detection limit was 0.5 µg mL-1. The calibration graph was rectilinear up to 50 µg mL-1. Interference was observed from Fe(III); most co-existing ions (e.g., Zn and Cu), sugars, amino-acids and organic acids (such as citric acid) did not interfere.
Ascorbic acid Spectrophotometry Buffer Interferences Kinetic Standard additions calibration

"Chemiluminescence Determination Of Ascorbic Acid With The Copper(II)-luminol System"
Fenxi Huaxue 1995 Volume 23, Issue 1 Pages 70-72
Feng, M.L.;Lu, J.R.;Zhang, Z.J.;Li, S.;Deng, Y.L.

Abstract: Sample solution was loaded into the flow chemiluminescence analyzer. to mix with 1 mM Cu(II) at pH 6 then with 0.25 mM luminol in a medium containing 0.1 M NaOH and 0.1 M NaHCO3 in a reaction coil of 20 cm in length prior to chemiluminescence detection. The calibration graph was linear for 2-60 M ascorbic acid with a detection limit of 0.62M. The RSD was 1.1%. Interference from Fe(II) and (III) was observed. The method was applied to assay of compound vitamin capsules, vitamin C tablets and beverages.
Ascorbic acid Chemiluminescence Interferences

"The Determination Of Sugars In Beverages And Medicines Using Online Dialysis For Sample Preparation"
Food Chem. 1995 Volume 53, Issue 1 Pages 105-110
Gillian M. Greenway and Nsanyi Kometa

Abstract: A method is described for the analysis of sugars in beverages and medicines using on-line dialysis for sample preparation. The design, construction and method development for the on-line dialysis is described. The dialysis is carried out using a novel polypropylene membrane treated for wettability (Celgard 3401) which is mechanically strong and solvent resistant when compared to traditional cellulose acetate membranes. Counter-current dialysis was used at a flow rate of 0.8 mL min-1, with a recipient stream of water and the dialysate was then analyzed by high-performance liquid chromatography. Fructose, glucose, lactose, maltose and sucrose were determined in a range of samples. The % RSD of the method was shown to be below 5% and the recoveries above 90% for all samples.
Sugars Sample preparation Dialysis

"Sulfite Determination Of Foods And Beverages"
Ind. Bevande 1988 Volume 17, Issue 97 Pages 398-400
Cipriani, I.

Abstract: Alternatives to the Monier-Williams assay for sulfites are outlined. In one procedure, a Kjeltec distillation app. is used to produce SO2, which is then trapped and titrated with NaOH. Alternatively, flow-injection anal. and colorimetry may be used. The reagents employed are either pararosaniline (which forms a complex with SO2 that absorbs at 560 nm) or malachite green (decolorization by SO2, monitored at 615 nm). When applied to food and wine, all 3 alternative procedures gave values that were consistent with the Monier-Williams method. (SFS)
Sulfite Spectrophotometry Method comparison

"Flow Injection Analysis - A New Technique For Food And Beverage Analysis"
Int. J. Food Sci. Technol. 1988 Volume 23, Issue 6 Pages 541-554
Osborne, B.G.;Tyson, J.F.

Abstract: A review is presented, with 49 references.

"Determination Of Trace Arsenic And Mercury In Drink By Hydride Generation-ICP-AES"
Sichuan Daxue Xuebao (Ziran Kexue Ban) 1996 Volume 33, Issue 4 Pages 419-423
Hu, M.;Huang, Q.;Xia, H.;Tong, S.

Abstract: A method for simultaneous determination of trace concentrations of As and Hg in drink have been investigated by continuous-flow mode hydride generation and inductively coupled plasma atomic emission spectrometry. The influence of operating conditions on the result of analysis is discussed. The proposed method is sensitive, accurate and easy to operate. The relative standard deviation is less than 5% if the concentration is 0.05-0.1 mg/L. The recovery of standard addition is 87-100%.
Arsenic Mercury Spectrophotometry Standard additions calibration

"Potentials Of Multisyringe Flow Injection Analysis For Chemiluminescence Detection"
Anal. Chim. Acta 2005 Volume 541, Issue 1-2 Pages 55-66
Manuel Mir&oacute;, Jos&eacute; Manuel Estela and V&iacute;ctor Cerd&agrave;

Abstract: In this paper, multisyringe flow injection analysis (MSFIA) is presented as a powerful and promising tool for automated liquid-phase chemiluminescence (CL) assays. The capability of operation under discontinuous forward flow regime while handling minute, well-defined volumes of sample and reagents in a multicommuted format offers unrivalled analytical features. As opposed to the parent flow injection (FI) and sequential injection (SI) analysis, CL reactions with divergent pH and kinetic demands can be easily implemented in a single protocol sequence, as demonstrated in the bulk of the text via luminol-based methods. MSFIA is proven extremely suitable for accommodating enzymatic CL assays in a renewable fashion by exploiting soluble enzymes, with no need for the typical immobilization procedures used in FI and SI systems. Solid-phase CL sensors have also gained full advantage of the benefits of MSFIA. In this context, a novel optosensor devised for on-line monitoring of trace levels of orthophosphate is described. Similar configurations are proposed for the selective and sensitive determination of metals, Vitamins, nutrients and saccharides in environmental and biological samples as well as beverages, which denotes the versatility of this automated flow technique. Special emphasis is also given to the simple instrumental set-up, including a dedicated flow-through luminometer, arranged for a multitude of CL assays.
Cobalt(II) Hydrogen peroxide Phosphate Chemiluminescence Multisyringe Automation Review Multiinjection