Thiabendazole uptake in shimeji, king oyster, and oyster mushrooms and its persistence in sterile and nonsterile substrates

Deposition amount and dissipation kinetics of difenoconazole and propiconazole applied on banana with two commercial spray adjuvants

A rapid and sensitive method for the simultaneous determination of difenoconazole and propiconazole residues in banana matrices was established using GC-MS/MS. The average recovery rates of difenoconazole and propiconazole from various matrices ranged from 76.7% to 94.9%. The relative standard deviation was between 0.9% and 7.4%. The effect of adding organosilicon and mineral oil adjuvants after being applied to the residues of difenoconazole and propiconazole in banana leaves was examined. The initial deposition amount 2 hours after the adjuvant treatment with organosilicon and mineral oil was 1.22–2.13 times higher than that after water treatment. After adding the two spray adjuvants, the residues of the two pesticides at 2 hours on three samples followed the order leaves > soil > fruit. The degradation half-lives of the two pesticides were in the range of 1.91–7.30 days for all the three treatments in two typical banana-growing areas in China. The degradation half-lives of the two pesticides in the water treatment group and the mineral oil treatment group were similar. However, organosilicon could apparently increase the half-life of difenoconazole on banana leaves. The final levels of difenoconazole and propiconazole residues on whole banana fruits were ≤0.1 mg kg⁻¹ (MRL) 14 days after application. The results of this work may aid the safe use of difenoconazole and propiconazole in banana production, especially when used with organosilicon and mineral oil adjuvants.

The effect of adding organosilicon and mineral oil adjuvants after being applied to the residues of difenoconazole and propiconazole in banana leaves was studied. The partition of the pesticides between soil, leaves and fruits was evaluated.

Analytical Confirmation of Various Herbicides in Drinking Water Resources in Sugarcane Production Regions of Guangxi, China

This work investigated drinking water contamination by 11 commonly used herbicides in sugarcane production areas in Guangxi, China. The work developed an analytical method for determination of these herbicides in environmental waters. This work studied herbicide residues in drinking water in Guangxi, China. The maximum residues and percent of detects were: (0.091 µg/L, 29.2%, atrazine), (0.018 µg/L, 8.3%, ametryne), (0.188 µg/L, 8.3%, aetolaehlor), (0.139 µg/L, 4%, simazine), (0.585 µg/L, 62.5%, atrazine), (0.311 µg/L, 33.3%, acetochlor), (0.341 µg/L, 58.3%, ametryne), (1.312 µg/L, 29.2%, metolachlor), (0.088 µg/L, 4.2%, alachlor), (0.127 µg/L, 14.3%, atrazine), and (0.453 µg/L, 7.1%, metolachlor), respectively. The results demonstrated that agricultural herbicides were detected in all water samples, including tap, surface and groundwater samples. Since the residues are generally below the safe limits established by the government authorities, the monitored 11 herbicides do not significantly affect the quality of the human environment. This work will provide scientific understanding of pesticide residues in drinking water standards in terms of its consistency with precautionary human health and environmental safety.

Behavior of Thiophanate Methyl and Propiconazole in Grape and Mango Fruits Under the Egyptian Field Conditions

This research aims at determining residues of thiophanate methyl and propiconazole in grape and mango fruits as an indication for their persistence in this environmental compartment. Fruit extracts were analyzed for thiophanate methyl using High Performance Liquid Chromatography and using Gas Chromatography Electron Capture Detector (GC/ECD), respectively. The results indicated that propiconazole had a less environmental impact since propiconazole had shorter residue half-lives which were 1.24 and 1.19 days in grape and mango fruits, respectively, while thiophanate methyl had half-lives of 2.49 and 2.64 days in mango and grape, respectively. The degradation rates of propiconazole in grape and mango fruits did not change significantly and neither did those of thiophanate methyl. According to the maximum residue level, the pre-harvest intervals of propiconazole were set to be 3 and 7 days for grape and mango fruits, respectively, and the pre-harvest intervals for thiophanate methyl were 15 days for both grape and mango fruits. Propiconazole was generally considered to be less hazardous to humans and will leave the environment less altered because of its faster degradation than that of thiophanate methyl.

Residual Behaviors of Six Pesticides in Shiitake from Cultivation to Postharvest Drying Process and Risk Assessment

The dissipation of six pesticides (carbendazim, thiabendazole, procymidone, bifenthrin, λ-cyhalothrin, and β-cyfluthrin) in shiitakes from cultivation to postharvest drying process was investigated, and the dietary exposure risk was estimated thereafter. The field trial study indicates that the half-lives of carbendazim, thiabendazole, and procymidone were much shorter than those of bifenthrin, λ-cyhalothrin, and β-cyfluthrin. Furthermore, the effects of two drying processes on the residues and processing factors (PFs) were investigated. The results showed that hot-air drying resulted in higher residues than sunlight exposure drying. Both drying processes led to pesticide residue concentration (with PF > 1), except for thiabendazole upon sunlight exposure treatment. The estimated daily intakes (EDIs) ranged from 0.06% of the acceptable daily intake (ADI) for thiabendazole to 42.43% of the ADI for procymidone. The results show that the six pesticide residues in dried shiitakes are still within acceptable levels for human consumption on the basis of a dietary risk assessment.

Residues and dissipation kinetics of triazole fungicides difenoconazole and propiconazole in wheat and soil in Chinese fields

An analytical method for simultaneously determining the residues of difenoconazole and propiconazole in wheat straw, wheat grain and soil was developed. Mean recoveries and relative standard deviations in all samples ranged 86.2-101.3% and 3.1-12.1% for propiconazole and difenoconazole. The half-lives of difenoconazole and propiconazole were 3.6-5.5days and 5.1-6.9days in wheat straws, and 4.9-5.8days and 6.1-8.4days in soil, respectively. The residues in wheat grain were found to be <0.01mg/kg, based on the application rate (135g a.i./ha) and the pre-harvest interval (PHI=28days) recommended by the manufacturer. The results suggest that the use of difenoconazole and propiconazole on wheat is considered to be safe under the Good Agricultural Practices (GAP) in the Chinese fields, and the main factors for pesticide residue in crops are application times, rates and pre-harvest intervals.