Optimization of flow-injection systems for determination of substrates by means of enzyme amplification reactions and chemiluminescence detection

Hansen, Elo Harald; Nørgaard, Lars; Pedersen, Mikael

doi:10.1016/0039-9140(91)80047-4

Cited by 42 publications

(7 citation statements)

References 11 publications

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“…Reagent (luminol) consumption and waste generation were lower than those of the cited literature [18,23,24]. These features could be considered as an improvement provided by the multicommutation approach.…”

Section: Discussionmentioning

confidence: 74%

Multicommuted flow system for the determination of glucose in animal blood serum exploiting enzymatic reaction and chemiluminescence detection

Pires¹,

Martelli²,

Reis³

et al. 2004

Journal of Automated Methods & Management in Chemistry

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An automatic flow procedure based on multicommutation dedicated for the determination of glucose in animal blood serum using glucose oxidase with chemiluminescence detection is described. The flow manifold consisted of a set of three-way solenoid valves assembled to implement multicommutation. A microcomputer furnished with an electronic interface and software written in Quick BASIC 4.5 controlled the manifold and performed data acquisition. Glucose oxidase was immobilized on porous silica beads (glass aminopropyl) and packed in a minicolumn (15 Â 5 mm). The procedure was based on the enzymatic degradation of glucose, producing hydrogen peroxide, which oxidized luminol in the presence of hexacyanoferrate(III), causing the chemiluminescence. The system was tested by analysing a set of serum animal samples without previous treatment. Results were in agreement with those obtained with the conventional method (LABTEST Kit) at the 95% confidence level. The detection limit and variation coefficient were estimated as 12.0 mg l À1 (99.7% confidence level) and 3.5% (n ¼ 20), respectively. The sampling rate was about 60 determinations h À1 with sample concentrations ranging from 50 to 600 mg l À1 glucose. The consumptions of serum sample, hexacyanoferrate(III) and luminol were 46 ml, 10.0 mg and 0.2 mg/determination, respectively.

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Section: Discussionmentioning

confidence: 74%

Multicommuted flow system for the determination of glucose in animal blood serum exploiting enzymatic reaction and chemiluminescence detection

Pires¹,

Martelli²,

Reis³

et al. 2004

Journal of Automated Methods & Management in Chemistry

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show abstract

“…The length of the reactor, the sample volume and the carrier flow rate were the factors to be studied using a 2 3 factorial design. The results showed that the significant fac- (6) chemiluminescence glucose [39] tors were the reactor length, the carrier flow rate and the interaction between the factors reactor length and carrier flow rate. Also, a full factorial design was used to investigate the effects of solvents and carriers on the oxidative chemiluminescence of phenylhydrazines [28].…”

Section: Factorial Designsmentioning

confidence: 95%

“…Therefore, R F is expressed by the equation R F =0.5R H +0.5(1-R T ), where R H and R T are the normalized forms of H and T, respectively and 0.5 is the weight used. Also, Hansen et al [39] proposed a response function as a linear combination of the peak height, the slope and the intercept of the calibration graph in order to minimize the limit of detection and to maintain a high sensitivity and a low blank value. Vereda et al [40] used an algebraic function to introduce quality compromises in the optimisation and then a response function was established in which selected criteria (sensitivity,…”

Section: Selection Of the Responsementioning

confidence: 99%

An overview of qualimetric strategies for optimisation and calibration in pharmaceutical analysis using flow injection techniques

Bosque-Sendra

Gámiz‐Gracia

Garcı́a-Campaña

2003

Analytical and Bioanalytical Chemistry

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Flow Injection analysis represents an attractive tool because of its great advantages, such as versatility, speed, high sampling rate and wide applicability in the field of pharmaceutical analysis. However, due to the inherent characteristics of the technique, the choice of the best set of operational and chemical conditions is complicated and the conventional univariate optimisation method present some limitations, mainly due to fact that the interdependence of variables is not considered. In relation to the calibration process, because of the transient character of the signals obtained using FIA manifolds coupled with different detection techniques, different strategies can be used in calibration to solve some problems related to the nature of the signal thereby improving the performance characteristics of the method. This paper offers an overview of different methodologies used in optimisation based on the use of statistically designed experiments and some strategies developed for calibration applied to the analysis of pharmaceuticals.

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“…(Mathematical model) Changes in the enzyme fluorescence during the reaction can be quantified via different parameters. In this work we used the following expression: t AI / Io = (Io -I)/I6, (7) where Io is the enzyme fluorescence intensity upon the addition of NAD, and It is that measured t seconds after lactate is added. The DI/ Io ratio allows one to estimate the relative decrease in the fluorescence signal during the reaction, and avoids any irreproducibility problems potentially arising from variations in the initial fluorescence of the enzyme.…”

Section: And Discussionmentioning

confidence: 99%

An Enzyme Fluorescence Quenching Method for the Determination of Lactate in Synthetic Blood Serum

1995

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An enzymatic fluorometric method for the determination of lactate based on its oxidation to pyruvate by NAD in the presence of lactate dehydrogenase (LDH) is proposed. The method relies on a decrease in the enzyme fluorescence during the reaction, which can be ascribed to the stability constant difference between the NAD-LDH and NADH-LDH complexes. A theoretical model was developed in order to predict the effect of the LDH and NAD concentrations on the analytical signal; also, the figures of merit of the proposed method were determined. The method allows the determination of lactate in synthetic blood serum with no interference, provided the sample is previously deproteinated with perchloric acid.

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Optimization of flow-injection systems for determination of substrates by means of enzyme amplification reactions and chemiluminescence detection

Cited by 42 publications

References 11 publications

Multicommuted flow system for the determination of glucose in animal blood serum exploiting enzymatic reaction and chemiluminescence detection

Multicommuted flow system for the determination of glucose in animal blood serum exploiting enzymatic reaction and chemiluminescence detection

An overview of qualimetric strategies for optimisation and calibration in pharmaceutical analysis using flow injection techniques

An Enzyme Fluorescence Quenching Method for the Determination of Lactate in Synthetic Blood Serum

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