The dissipation kinetics of malathion in aqueous extracts of different fruits and vegetables

Abstract

The dissipation of malathion in 5% aqueous extracts of some fruits and vegetables including bell pepper, tomato, cucumber, cantaloupe, carrot, and also buffer (control) was investigated at 37 °C for 4 h. The dissipation trend of malathion in the fruit/vegetable samples and buffer followed first-order double-exponential decay (FODED) and simple first-order kinetic (SFOK) models, respectively. The initial dissipation rate of malathion in tomato (DT10=0.05 h), bell pepper (DT10=0.06 h), and carrot (DT10=0.07 h) was faster compared to the other samples. The slowest rate of pesticide decline belonged to cantaloupe (DT50=1.92 h) with a significant difference from the other samples (p≤0.01), whereas tomato (DT50=0.43 h) and carrot (DT50=0.53 h) showed the fastest dissipation rate. DT90 values derived from the models revealed no significant difference between the samples except for cantaloupe which had the slowest rate of dissipation (DT90=8.27 h) with a significant difference compared to others (p≤0.01). A direct correlation was observed between protein content of the samples and the rate of malathion decline which indicates the role of plant enzymes in degrading malathion residues.

Residue kinetics of neonicotinoids and abamectin in pistachio nuts under field conditions: model selection, effects of multiple sprayings, and risk assessment

“…The estimated method detection limit (EMDL) was calculated according to Singh et al (2007) based on the calculated IDL and the mean recovery of each pesticide from pistachio nuts. Details of the methods are described elsewhere (Rahimi et al 2015;Torabi et al 2017). Blank pistachios were spiked at the EMDL of each pesticide, and recoveries were checked to confirm the limit of detection (LOD) and limit of quantification (LOQ).…”

“…8) demonstrates the balance between the goodness of fit of a model and its complexity. A model with the minimum AIC value is considered the best (Sarmah and Close 2009;Rahimi et al 2015).…”

“…These distribution processes result in decreased pesticide levels in sap water compared to the outside surface concentrations, which will keep the driving force for passive uptake of the chemicals until reaching the partition limit (e.g., an equilibrium) (Liu et al 2021). Also, several exponential decay models, including the simple first-order kinetic (SFOK), zero-order (ZO), second-order (SO), and first-order double-exponential decay (FODED), have been utilized to predict the dissipation trends of agrochemicals in crops (Utture et al 2012;Torabi and Talebi 2013;Rahimi et al 2015;Ramezani and Shahriari 2015;Chen et al 2016;Alister et al 2017;Torabi et al 2017;Lee et al 2019). SFOK, ZO, and SO are log-linear models which consider pesticide dissipation a mono-phasic process with a single rate constant (see Eqs.…”

Effects of Monochoria vaginalis density on yield losses, economic thresholds, and gross returns in paddy rice (Oryza sativa L.)

“…The best fitted model was selected based on the goodness‐of‐fit (Rahimi et al., 2015) using the normalized root‐mean‐square error (NRMSE), coefficient of residual mass (CRM), and Akaike information criterion (AIC), calculated using Equations (Rahimi et al., 2015): where M av is the average value of the measured rice yield trait, F i is the fitted trait value, M i is the measured trait value, ESS is the error sum of squares, n is the number of observations, and q is the number of parameters. NRMSE and CRM values close to zero indicate good agreement between the predicted and observed values, whereas the lowest AIC indicates the best fitted model (Sarmah & Close, 2009).…”

Degradation kinetics and physiological studies of organophosphates degrading microorganisms for soil bioremediation

“…Indeed, diazinon is among the most detected organophosphate in crop products despite its ban in some countries (Sapbamrer and Hongsibsong 2014 ). Diazinon residue in crops above allowable limit (0.01 mg kg −1 body weight) have been reported in a number of developed countries (Rahimi et al 2015 ). Moreover, extensive application of diazinon in field crops can result in accumulation of the chemical in soil and could be absorbed by growing crop during growing period (Wang et al 2019 , b ).…”