Automatic flow kinetic-catalytic methods

Henríquez, Camelia; Maya, Fernando; Phansi, Piyawan; Abouhiat, Fatima Zohra; Danchana, Kaewta; Cerdà, Vı́ctor

doi:10.1016/j.trac.2016.08.009

Cited by 9 publications

(2 citation statements)

References 68 publications

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“…A pioneering application of a catalytic method in unsegmented flow analysis was focused on vanadium determination at the nanogram level relying on the V(V) effect on the chromotropic acid-bromate indicator reaction [ 21 ]. Applications involving the determinations of metal ions, anions, and organic species by different flow modalities, including chip-based analyzers, were recently reviewed [ 22 ]. The authors foresaw the exploitation of catalytic methods for post-column chemical derivatization in chromatography.…”

Section: Chemical Derivatizationmentioning

confidence: 99%

Chemical Derivatization in Flow Analysis

Rocha

Zagatto

2022

Molecules

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Chemical derivatization for improving selectivity and/or sensitivity is a common practice in analytical chemistry. It is particularly attractive in flow analysis in view of its highly reproducible reagent addition(s) and controlled timing. Then, measurements without attaining the steady state, kinetic discrimination, exploitation of unstable reagents and/or products, as well as strategies compliant with Green Analytical Chemistry, have been efficiently exploited. Flow-based chemical derivatization has been accomplished by different approaches, most involving flow and manifold programming. Solid-phase reagents, novel strategies for sample insertion and reagent addition, as well as to increase sample residence time have been also exploited. However, the required alterations in flow rates and/or manifold geometry may lead to spurious signals (e.g., Schlieren effect) resulting in distorted peaks and a noisy/drifty baseline. These anomalies can be circumvented by a proper flow system design. In this review, these aspects are critically discussed mostly in relation to spectrophotometric and luminometric detection.

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Section: Chemical Derivatizationmentioning

confidence: 99%

Chemical Derivatization in Flow Analysis

Rocha

Zagatto

2022

Molecules

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“…Flow techniques are especially attractive for kinetic-catalytic methods of analysis [ 7 , 8 ], where highly reproducible conditions of reagents dosing, mixing, and transport as well as the precise control of reaction/incubation times are crucial. Such conditions are especially important in the case of enzyme activity assays.…”

Section: Introductionmentioning

confidence: 99%

Multicommutated Flow Analysis System for Determination of Horseradish Peroxidase and Its Inhibitors

2021

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A fully mechanized multicommutated flow analysis (MCFA) system dedicated to determining horseradish peroxidase (HRP) activity was developed. Detection was conducted using a flow-through optoelectronic detector-constructed of paired LEDs operating according to the paired emitter-detector diode (PEDD) principle. The PEDD-MCFA system is dedicated to monitoring the enzyme-catalyzed oxidation of p-phenylenediamine (pPD) by a hydrogen peroxide. Under optimized conditions, the presented bioanalytical system was characterized by a linear response range (33.47–200 U/L) with a detection limit at 10.54 U/L HRP activity and 1.66 mV·L/U sensitivity, relatively high throughput (12 signals recordings per hour), and acceptable precision (RSD below 6%). Additionally, the utility of the developed PEDD-MCFA system for the determination of HRP inhibitors allowing the detection of selected thiols at micromolar levels, is demonstrated. The practical utility of the flow system was illustrated by the analysis of some dietary supplements containing L-cysteine, N-acetylcysteine, and L-glutathione.

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