Enzymatic Determination of Organic Phosphorus Insecticides

Giang, P. A.; Hall, S. A.

doi:10.1021/ac60060a032

Cited by 100 publications

(23 citation statements)

References 7 publications

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“…Prior to determination of thionophosphorus pesticides with ChE, they were oxidised to the corresponding oxygen analogues with bromine water 114 or 50% nitric acid. 115 An effective procedure has been also developed for the oxidation of thionophosphates with chlorine or bromine generated in situ by galvanostatic electrolysis. 116 Quaternary ammonium salts, acridine derivatives and metal ions are also known as reversible inhibitors of ChE.…”

Section: Cholinesterase-based Biosensorsmentioning

confidence: 99%

“…In order to extend the range of compounds that can be determined by this method, some investigators deliberately decrease the selectivity of the biosensor response through simultaneous use of several ChE isolated from different sources. 115,160 Tissue homogenates or biological fluids possessing esterase activity (blood, liver homogenates, etc.) are used for the same purpose.…”

Section: Cholinesterase-based Biosensorsmentioning

confidence: 99%

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Biosensors for the determination of environmental inhibitors of enzymes

Evtugyn¹,

Budnikov²,

Nikol'skaya³

1999

Russ. Chem. Rev.

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Section: Cholinesterase-based Biosensorsmentioning

confidence: 99%

Section: Cholinesterase-based Biosensorsmentioning

confidence: 99%

Biosensors for the determination of environmental inhibitors of enzymes

Evtugyn¹,

Budnikov²,

Nikol'skaya³

1999

Russ. Chem. Rev.

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“…The classical method suggested by Giang and Hall (1951) uses acetylcholine and the residual activity of the enzyme is determined by titrating the acetic acid with an alkali. Kramer and Guilbaut (1965) used the fluorescent method for controlling the cholinesterase activity.…”

Section: Introductionmentioning

confidence: 99%

Effect of hypochlorite oxidation on cholinesterase-inhibition assay of acetonitrile extracts from fruits and vegetables for monitoring traces of organophosphate pesticides

et al. 2014

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-A reproducible method for monitoring traces of cholinesterase (ChE) inhibitors in acetonitrile extracts from fruits and vegetables is described. The method is based on hypochlorite oxidation and ChE inhibition assay. Four common representative samples of produce were selected from a supermarket to investigate the effect of different matrices on pesticides recoveries and assay precision. The samples were extracted with acetonitrile to prepare them for ChE inhibition assays: if necessary, clean-up was performed using dispersive solid-phase extraction for gas chromatography-mass spectrometry (GC/ MS) analyses. Chlorine was tested as an oxidising reagent for the conversion of thiophosphorus pesticides (P=S compounds) into their P=O analogues, which have high ChE-inhibiting activity. Chlorine consumption of individual acetonitrile extracts was determined and was strongly dependent on the individual types of fruits and vegetables. After treating the acetonitrile extracts with an excess hypochlorite at 25°C for 15 min, the ChE-inhibiting activities and detection limits for each chlorine-treated pesticide solution were determined. Matrix composition did not interfere significantly with the determination of the pesticides. Enhanced anti-ChE activities leading to low detection limits (ppb levels) were observed for the chlorinetreated extracts that were spiked with chlorpyrifos, diazinon, fenitrothion, and isoxathion. This combination of oxidative derivatisation and ChE inhibition assays was used successfully to monitor and perform semi-quantitative determination of ChE inhibitors in apple, tomato, cucumber, and strawberry samples.

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“…In the classical method suggested by Giang and Hall (1951), acetylcholine is used and the residual activity of the enzyme is determined by titrating the acetic acid with an alkali. Kramer and Guilbault (1965) used the fluorescent method for controlling the cholinesterase activity.…”

Section: Introductionmentioning

confidence: 99%