Storage stability of organophosphorus pesticide residues in peanut and soya bean extracted solutions

Abstract

This study was performed to determine the storage stability of organophosphorus pesticide residues in high oil content commodity matrices, peanut and soya bean. The storage conditions included different types of solvents (ethyl acetate, acetone and hexane) and corresponding extracted matrix solutions, light and temperature. It was found that three pesticides degraded quickly especially in ethyl acetate solvent. They decreased greater than 30% when stored for 3 days at −20°C in ethyl acetate; the results showed that the stability could be improved in the extracted matrix solutions. Light had a slight effect for stability of phorate and fenthion, while it played an important effect for disulfoton with the exception of ethyl acetate as solvent. Even at −20°C, exposure to solvents or extracted matrix solution resulted in 40.67, 96.33 and 35.07% loss of phorate, disulfoton and fenthion. Hence, it could be assumed that these three residues could be more stable at lower temperature, in the dark and in acetone or hexane extracted peanut and soya bean solutions.

Simultaneous Determination of the Residues of Isopyrazam Isomers and Their Metabolites in Soil and Tomatoes by Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry

“…There was no obvious selective degradation trend in syn- IZM and anti -IZM. According to the OECD standard, the compound was stable in analytical samples when the degradation rate was less than 30%. , In the present study, the maximum degradation rate of the four compounds in tomato at −20 °C within 36 weeks was 16.0%, indicating that the four compounds were stable in tomato at −20 °C within 36 weeks. These results were consistent with the storage stability results of a previous study of IZM on wheat, apple, orange, etc.…”

Application of the QuEChERS method combined with UHPLC-QqQ-MS/MS for the determination of isoprocarb and carbaryl pesticides in Indonesian coffee

“…The use of standard addition could eliminate the matrix effect and improve the test result accuracy, but it will waste time and chemicals in its preparation. Since pesticides could remain stable in sample extracts used as calibrants for several days, 20,21 and the stability study of isoprocarb and carbaryl in sample extracts of coffee beans was performed. The storage stability of the spike concentrations of 10, 50, and 100 mg kg −1 , which were stored at 25, 4, and −20 °C in clear and amber vials, respectively, was observed for 7 days.…”

Domination of Pollutant Residues among Food Products of South-East Asian Countries

“…Widespread agricultural use of pesticides and home storage make them easily available for acts of self-harm in many rural households. Stability of organophosphorus pesticides is also important issue [43]. It was found that Malathion was more unstable than dichlorvos and diazinon; there was an over 70% loss in 90 days even at -20 °C in coarsely chopped form [44].…”