Effect of cysteine on the stability of ethylenethiourea and ethylenebis(dithiocarbamate) in crops during storage and/or analysis

Kobayashi, Hiroko; Nishida, Mayumi.; Matano, Osami; Goto, Shinko

doi:10.1021/jf00013a015

Cited by 24 publications

(15 citation statements)

References 15 publications

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“…Lower limits for EBDC analysis in environmental matrices were established in the ppm range by HPLC with UV detection 16. Studies on ETU determination in various food commodities continued to evolve rapidly towards new methods based on the use of technologies such as gas chromatography coupled with mass spectrometry (GC/MS),17 and HPLC coupled with UV,18–22 electrochemical,23 and MS detectors 24,25…”

mentioning

confidence: 99%

Analytical method for the quantitative determination of urinary ethylenethiourea by liquid chromatography/electrospray ionization tandem mass spectrometry

Sottani

Bettinelli

Fiorentino

et al. 2003

Rapid Comm Mass Spectrometry

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A direct, rapid and selective method for the quantitative determination of the ethylenethiourea (ETU) in human urine has been validated and is reported in the present study. It allows the accurate quantification of ETU in this complex matrix without the use of any internal standard as the sample cleanup is effective enough for the removal of interferences that could lead to ion suppression in the electrospray ionization (ESI) source. This simple and rapid purification system, based on the use of a Fluorosil phase of a BondElut column followed by a liquid-liquid extraction procedure, achieves mean extracted recoveries, assessed at three different concentrations (2.5, 10.0, and 25.0 microg/L), always more than 85%. High-performance liquid chromatography (HPLC) with positive ion tandem mass spectrometry, operating in selected multiple reaction monitoring (MRM) mode, is used to quantify ETU in human urine. The assay is linear over the range 0-50 microg/L, with a lower limit of quantification (LOQ) of 1.5 microg/L and a coefficient of variation (CV) of 8.9%. The lower limit of detection (LOD) is assessed at 0.5 microg/L. The overall precision and accuracy were determined on three different days. The values for within- and between-day precision are < or = 8.3 and 10.1%, respectively, and the accuracy is in the range 97-118%. The relative uncertainties for the LOQ and QC concentrations have been estimated to be 18 and 8%, respectively. The assay was applied to quantify ETU in human urine from growers that regularly handle ethylenebisdithiocarbamate pesticides in large crop plantations. The biological samples were collected at the start and end of the working day, and the ETU urine levels were found to vary between 1.9 and 8.2 microg/L.

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mentioning

confidence: 99%

Analytical method for the quantitative determination of urinary ethylenethiourea by liquid chromatography/electrospray ionization tandem mass spectrometry

Sottani

Bettinelli

Fiorentino

et al. 2003

Rapid Comm Mass Spectrometry

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“…Thus, we attempted to prevent degradation by adding DTT as a stabilizer, as it has been reported that reducing agents are effective stabilizers. 26) In this case, we could not select cysteine, [12][13][14][15][16][17][22][23][24][25] as the retention times for the methylated form of cysteine and DDMe were comparable under the same MS/MS conditions due to their similar molecular weights. Thus, we also investigated the effect of the DTT concentration on the samples and found that degradation was prevented in a number of cases, resulting in enhanced methylation rates.…”

Section: Optimization Of the Sample-preparation Methodsmentioning

confidence: 99%

A rapid and sensitive analysis of dithiocarbamate fungicides using modified QuEChERS method and liquid chromatography–tandem mass spectrometry

Kakitani

Yoshioka

Nagatomi

et al. 2017

Journal of Pesticide Science

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We herein present a method for the analysis of 10 dithiocarbamate fungicides (DTCs) in beer, fruit juice, and malt samples, where the DTCs were converted into water-soluble sodium salts in the presence of NaHCO 3 prior to methylation using dimethyl sulfate. Extraction of the methylated compounds from matrices was performed using a "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method. Following a dispersive solid-phase extraction as a clean-up step, the methylated compounds were detected by liquid chromatography-tandem mass spectrometry. Performance evaluation was carried out on beer, fruit juice, and malt samples using representative compounds. Accuracies of the spiked compounds from the various matrices ranged from 92.2 to 112.6%, and the limits of quantification of propineb, mancozeb, and thiuram were <0.52, <0.55, and <6.97 µg/kg, respectively. The developed method was then applied in the determination of dithiocarbamate fungicide contents in commercial beer and fruit juice samples.

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“…Maštovská and Lehotay (2004) investigated the stability of phorate, disulfoton, and fenthion, these three pesticides containing a thioether group were prone to oxidized into sulfone and sulfoxide in the environment or living organisms, the structural formulas of thioether-linked pesticides involved in the research and their main metabolic pathways in living organisms were listed. The type of matrices could also affect stability of pesticide residues owning to differences in organic matter content, pH, water content, and so on (Kobayashi, Nishida, & Matano, 1992;Mouvet et al, 1997;Sun & Lee, 2003). Leahey and Curl (1982) found that the loss of pirimiphos-methyl depended to a certain extent on the humidity of the rice samples.…”

Section: Dementioning

confidence: 99%

“…Nakamura Y. investigated the influence of different sample forms of storage on organophosphorus insecticides on rice and concluded that sample form affected the storage stability of the pesticides (Nakamura et al, 1993). As demonstrated by Kobayashi et al (1992), adding cysteine to the samples could retard the degradation rate of ethylene thioure. The role of cysteine was to inhibit the conversion of ethylenediamine dithiocarbamate to ethylene thiourea.…”

Section: Dementioning

confidence: 99%

Storage stability improvement of organophosphorus insecticide residues on representative fruit and vegetable samples for analysis

Dong

Bian

Liu

et al. 2019

J Food Process Preserv

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Accuracy of data for pesticide residues analysis is particularly important because analytical results are the basis for risk assessment and taking regulatory action. We, therefore, investigated the storage stability of eight organophosphorus pesticides on seven different kinds of matrices under different conditions; and the improvement measures of the stability of five pesticides on cabbage and potato were studied. The results confirmed the reduction of pesticide residue levels over time due to the storage conditions, the properties of the pesticide and characteristics of the matrices. It was found temperature was most important for stability and had the greatest effect on diazinon, pirimiphos‐methyl, and methidathion. Another promising finding was that adding the copper ion, sulfur powder, methanol, dichloromethane, and adjusting pH to acidity could improve the stability of the five pesticides. The results indicated that methods to apply some extra substrates need to be identified and intensively studied to improve storage stability of organophosphorus pesticides. Practical applications Undesired loss of pesticides at the sample storage stage and subsequent analytical steps will result in an underestimate of residue levels with possible implications on MRL compliance monitoring, risk assessments, and measurement uncertainty. Regulatory agencies can no longer afford to ignore the contribution of storage stability to the uncertainty results owning to the high risks involved. Our research topic is how to improve storage stability. These measures can be applied to actual production and have important significance for the evaluation of unstable pesticides during storage. This also provides data support and research basis for future storage stability studies.

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Effect of cysteine on the stability of ethylenethiourea and ethylenebis(dithiocarbamate) in crops during storage and/or analysis

Cited by 24 publications

References 15 publications

Analytical method for the quantitative determination of urinary ethylenethiourea by liquid chromatography/electrospray ionization tandem mass spectrometry

Analytical method for the quantitative determination of urinary ethylenethiourea by liquid chromatography/electrospray ionization tandem mass spectrometry

A rapid and sensitive analysis of dithiocarbamate fungicides using modified QuEChERS method and liquid chromatography–tandem mass spectrometry

Storage stability improvement of organophosphorus insecticide residues on representative fruit and vegetable samples for analysis

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