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: Food -> beef -> cube

Citations 4

"Determination Of The Substrates Of Dehydrogenases In Biological Material In Flow Injection Systems With Electrocatalytic NADH Oxidation"
Anal. Chim. Acta 1984 Volume 163, Issue 1 Pages 299-303
A. Schelter-Graf, H. -L. Schmidt and H. Huck

Abstract: Applications are described of the NADH-sensitive system described previously (Huck et al., Anal. Abstr., 1984, 46, 8J126) that incorporated epoxyacrylic resin-bound dehydrogenases and a modified graphite electrode. The determination of D- and L-lactate in butter, L-glutamate in beef cubes, and ethanol in beer, and the control of the enzymatic hydrolysis of N-acetyl-DL-leucine by aminoacylase are discussed. The results obtained agreed well with those by spectrophotometric methods.
Ethanol l-Glutamate d-Lactate l-Lactate N-Acetyl-DL-leucine Electrode Potentiometry Method comparison Reactor Enzyme

"Simultaneous Spectrophotometric Determination Of Nitrite And Nitrate By Flow Injection Analysis"
Talanta 1996 Volume 43, Issue 7 Pages 1009-1018
M. J. Ahmeda, C. D. Stalikasa, S. M. Tzouwara-Karayannia and M. I. Karayannisa,*

Abstract: Meat products, flour, soil, beer and cheese were prepared and digested by the AOAC method ['Official Methods of Analysis of the Association of Official Analytical Chemists', Helrich (Ed.), Association of Official Analytical Chemists, Arlington, VA, USA, 1990]. The digests were filtered and the filtrate or filtered water was diluted with 0.4 M NH4Cl. The prepared samples or standards were injected into a carrier stream (0.4 ml/min) of 0.4 M NH4Cl, the stream was split into two and one stream passed through a glass reaction column (2 cm x 3 mm i.d.) packed with copper particles and a reduction column (10 cm x 3 mm i.d.) packed with copperized cadmium granules. The reduced stream merged with a reagent stream (1 ml/min) of 7.24 mM 3-nitroaniline/3.86 mM N-(1-naphthyl)- ethylenediamine dihydrochloride (1:5), the resulting stream passed through a reaction coil (50 cm) and the absorbance was measured at 535 nm. The second part of the stream by-passed the reduction columns, merged with the reagent stream and the absorbance was measured. Calibration graphs were linear for 0.01-2.2 µg/ml of nitrite and 0.1-3.5 µg/ml of nitrate with detection limits of 1 ng/ml and 10 ng/ml, respectively. The RSD (n = 5) were 0.1-2% over the calibration range for nitrate and nitrite. The permissible levels of interfering ions are tabulated.
Nitrate Nitrite Sample preparation Spectrophotometry Interferences Column Reduction column

"Spectrophotometric Simultaneous Determination Of Creatinine And Creatine By Flow Injection With Reagent Injection"
Fresenius J. Anal. Chem. 1995 Volume 352, Issue 6 Pages 557-561
Gloria del Campo, Ana Irastorza and J. Alfonso Casado

Abstract: Stock cubes (meat and fish) were dissolved in water by heating at 60°C with agitation and the resulting solution was cooled and filtered. After dilution with water a 220 µL portion was injected into the carrier stream of 2 g/l picric acid in 20 g/l NaOH in a FIA system. The system passed through a reaction coil (600 cm x 0.7 mm i.d.) and merged with 0.2 g/l of biacetyl and 25 g/l of 1-naphthol in 20 g/l of NaOH. The resulting stream passed through a second reaction coil (500 cm x 0.7 mm i.d.) to a spectrophotometer where the absorbance was measured at 520 nm. All flow rates were 0.9 ml/min and all reactions took place at 40°C. Calibration graphs were linear up to 30 mg/l of creatinine and creatine. RSD (n = 3) were 0.3-1.65% for 2-20 mg/l of creatinine and 0.34-0.67% for 2-30 mg/l of creatine. Recoveries were 99.6-102.9% for creatinine and 96.5-100.4% for creatine from meat and fish stock cubes.
Creatine Creatinine Spectrophotometry Heated reaction Reverse

"Bioluminescent Flow Sensor For L-glutamate"
Anal. Lett. 1992 Volume 25, Issue 4 Pages 637-652
Girotti, S.;Ghini, S.;Budini, R.;Pistillo, A.;Carrea, G.;Bovara, R.;Piazzi, S.;Merighi, R.;Roda, A.

Abstract: The method for the analysis of serum or meat, fish or vegetable extract is based on the reaction of the analyte with NAD+ and glutamate dehydrogenase (NAD(P)+). The NADH produced was monitored by the luminescence generated by its reaction with NAD(P)H dehydrogenase (FMN) and luciferase (both from Photobacterium fischeri). The reductant enzyme and the luminescent enzymes were immobilized on separate nylon coils in a continuous-flow system similar to that described previously [Analyst (London), 1990, 115, 889]. The calibration graph was rectilinear from 50 to 1000 µM with coefficient of variation (n = 7) of 7%. The recoveries were between 88 and 105%. The results agreed well with those obtained by a spectrophotometric method for stock cubes and by a chromatographic method for serum.
l-Glutamate Bioluminescence Sensor Immobilized enzyme Nylon Method comparison