Studies on Analysis of Organophosphorus, Pyrethroid and Organonitrogen Pesticides in Vegetables and Fruits

Takahashi, Kunihiko; Ishii, Rie; Iijima, Masao; Hoshino, Youji

doi:10.3358/shokueishi.36.607

Cited by 3 publications

(3 citation statements)

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“…Different products were obtained depending on the solvent and light sources: Ethiofencarb sulfoxide was the main product of irradiation in cyclohexane, whereas photo‐oxidation, hydrolysis, and addition product formation were observed when the photolysis took place in isopropanol. The determination of residues of ethiofencarb in surface water 8, grain, fruits, and vegetables was reported 9–15. Analyses were performed using HPLC with ultraviolet or fluorescence detection and gas chromatography (GC) in combination with nitrogen phosphorus detection after a derivatization step.…”

Section: Introductionmentioning

confidence: 99%

Alkaline hydrolysis of ethiofencarb: Kinetic study and mechanism degradation

Ouertani

Latrous

Hamida

2012

Int J of Chemical Kinetics

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The present paper deals with the hydrolysis of ethiofencarb [2ethylthiomethyl(phenyl)-N-methylcarbamate] in alkaline solution. The reaction kinetics has been investigated using spectrophotometric and liquid chromatographic techniques. The rate constants were determined following a proposed first-order kinetic model. The positive activation entropy S = = +100.07 J mol −1 K −1 and the absence of general basic catalysis indicated an E1cB hydrolytic mechanism, involving the formation of methyl isocyanate. This result was confirmed by the fact that ethiofencarb fits well into Brönsted and Hammett lines, obtained for a series of substituted N-methylcarbamate whose decomposition in aqueous media was established to follow an E1cB mechanism. C 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: [118][119][120][121][122][123][124] 2013

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Section: Introductionmentioning

confidence: 99%

Alkaline hydrolysis of ethiofencarb: Kinetic study and mechanism degradation

Ouertani

Latrous

Hamida

2012

Int J of Chemical Kinetics

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“…In all cases, the determination was performed by GC-NPD (Barrio et al 1996). Sometimes the LLE of ETF from fruits and vegetables is not efficient and the extract must be purified by Florisil column chromatography (Takahashi et al 1995) or with gel permeation chromatography (GPC) (Ueno et al 2002). Alternatively, the determination of residues of ETF can be performed using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection (Bicchi et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Electroanalytical Study of the Pesticide Ethiofencarb

et al. 2006

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A detailed study of voltammetric behavior of ethiofencarb (ETF) is reported using glassy carbon electrode (GCE) and hanging mercury drop electrode (HMDE). With GCE, it is possible to verify that the oxidative mechanism is irreversible, indepen-dent of pH, and the maximum intensity current was observed at þ1.20 V vs. AgCl/Ag at pH 1.9. A linear calibration line was obtained from 1.0 Â 10 24 to 8.0 Â 10 24 mol L 21 with SWV method. To complete the electrochemical knowledge of ETF pesticide, the reduction was also explored with HMDE. A well-defined peak was observed at -1.00 V vs. AgCl/Ag in a large range of pH with higher signal at pH 7.0. Linearity was obtained in 4.2 Â 10 26 and 9.4 Â 10 26 mol L 21 ETF concentration range.An immediate alkaline hydrolysis of ETF was executed, producing a phenolic compound (2-ethylthiomethylphenol) (EMP), and the electrochemical activity of the product was examined. It was deduced that it is oxidized on GCE at þ0.75 V vs. AgCl/Ag with a maximum peak intensity current at pH 3.2, but the compound had no reduction activity on HMDE.Using the decrease of potential peak, a flow injection analysis (FIA) system was developed connected to an amperometric detector, enabling the determination of EMP over concentration range of 1.0 Â 10 27 and 1.

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“…Most methods are part of a multi-residue, often multimatrix, scenario, and are not specific to pendimethalin. Pendimethalin recoveries have been reported using some of the above-mentioned methods (11,12,(16)(17)(18).…”

Section: Introductionmentioning

confidence: 99%

Analysis of Pendimethalin Residues in Fruit, Nuts, Vegetables, Grass, and Mint by Gas Chromatography

Engebretson

Hall

Hengel

et al. 2001

J. Agric. Food Chem.

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Pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine], in the formulation of Prowl (a commercial herbicide), was applied to various crops. Analysis of pendimethalin and its metabolite [4(1-ethylpropyl)amino-2-methyl-3,5-dinitrobenzyl alcohol] was accomplished by utilizing liquid-liquid partitioning, gel permeation chromatography (GPC) for nuts and mint, solid-phase extraction (SPE) cleanup, and gas chromatography (GC) with a nitrogen--phosphorus detector (NPD). Method validation recoveries for fruits, nuts, vegetables, grass, and mint are given for both compounds. Pendimethalin average recoveries ranged from 71% to 126% over two levels of fortification. Pendimethalin metabolite average recoveries ranged from 69% to 123% over two levels of fortification. The quantitation limit for all crops except mint was 0.050 ppm. The quantitation limit for mint and mint oil was 0.10 ppm. Residues greater than the limit of quantitation were found for pendimethalin in apple pomace, fresh and dry fig, grass screenings, mint oil, almond hulls, green onion, and tomato pomace (wet and dry). Residues greater than the limit of quantitation were found for pendimethalin metabolite in grass screenings, grass straw, and almond hulls. All other crop analyses for pendimethalin and its metabolite were below the limit of quantitation.

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Studies on Analysis of Organophosphorus, Pyrethroid and Organonitrogen Pesticides in Vegetables and Fruits

Cited by 3 publications

References 0 publications

Alkaline hydrolysis of ethiofencarb: Kinetic study and mechanism degradation

Alkaline hydrolysis of ethiofencarb: Kinetic study and mechanism degradation

Electroanalytical Study of the Pesticide Ethiofencarb

Analysis of Pendimethalin Residues in Fruit, Nuts, Vegetables, Grass, and Mint by Gas Chromatography

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