Assessment of different washing treatments to mitigate imidacloprid and acetamaprid residues in spinach

Evaluating the effectiveness of different household washing techniques for removal of insecticides from spinach and chickpea leaves by micellar liquid chromatography

In the past few decades, the employment of green analytical approaches in chromatographic method development has attracted the analytical separation community. The greenness of the developed method depends upon the toxicity of solvents and the amount of generated post-analysis waste generated. In this concern, micellar liquid chromatography (MLC) is a simple and rapid technique that generates very low toxic waste compared to traditional chromatographic pesticide detection methods. Here, MLC method has been validated and applied for the determination of monocrotofos (MCF), imidacloprid (ICP), dimethoate (DM) and profenofos (PFF) in spinach and chickpea leaves. The optimized mobile phase was 0.065 M SDS-2 % 1-propanol, 0.01 M NaH2PO4 buffered to pH 7. A C18 column was used for separation with a flow rate of 1 mL/min. The developed method has been validated following the guidelines of SANTE/11,312/2021 and ICH guidelines for; limit of quantification (0.05-0.20 mg/kg), linearity (r2> 0.997-0.999), precision (<6.3 %), accuracy (96.3 %-99.8 %) and robustness (<6) in real samples. ICP and MCF, apart from DM and PFF, were detected in the present work. After detecting insecticides in spinach and chickpea leaves both were washed with different household chemicals i.e. normal, lukewarm, common salt, lemon juice water and commercial ozonizer. Based on five washing techniques with insecticide concentration time intervals reduction rates were calculated for each washing treatment. The results show that lemon juice, common salt water, and ozonizer can be used as washing techniques for the reduction of superficial and systematic residues of ICP and MCF. Common salt and lemon juice water were better for washing over vinegar and potassium permanganate (KMnO4) as they enhance the colour of the green leafy vegetables and are available in every Indian kitchen. They can be easily used by lower socioeconomic classes who cannot afford KMnO4 and vinegar.

Consumer Awareness and Health Risk Perceptions of Pesticide Residues in Fruits and Vegetables in Kampala Metropolitan Area in Uganda

Consumer awareness of the presence of pesticides in fruits and vegetables and associated health risks influences the actions they undertake to reduce their exposure. This study was carried out to explore consumers' awareness of pesticide residues in fruits and vegetables and perceptions towards associated health effects in Kampala Metropolitan Area (KMA) in Uganda. Eight focus group discussions (FGDs) were done with fruit and vegetables consumers in KMA. The FGDs consisted of females and males living in urban and rural areas. Discussions were recorded and transcribed. The transcripts were coded inductively and analysed using conventional content analysis. Consumers were aware of the presence of pesticide residues in fruits and vegetables. Non-compliance to good agricultural practices, desire to produce good quality fruits and vegetables, and conflict of interest were thought to be the underlying reasons for the contamination. Consumers thought that their health is at risk of chronic and acute health effects, and that this risk is unavoidable. They emphasized that long term exposure to the pesticide residues puts them at risk of conditions like reproductive defects and noncommunicable diseases like cancer, hypertension, obesity, kidney and heart diseases among others. To reduce the risk, consumers were aware of and relied on mitigation measures including washing, peeling, drying and cooking or applied them in combination. Consumers were aware of the presence of pesticide residues on fruits and vegetables, potential short and long term health risks due to exposure, and domestic processing methods to reduce health risks. There is need for authorities to ensure adherence to good agricultural practices and ensure that farmers and consumers understand that pesticide are used to control pests and disease but not to primarily increase shelf life of fruits and vegetables.

Optimization of a rice cooking method using response surface methodology with desirability function approach to minimize pesticide concentration

Rice is contaminated with pesticides applied in pre and post-harvest. These contaminations could be reduced through household operations like washing and cooking. Therefore, in the present research, a pre-soaking rice cooking method was used to reduce pesticides residues. Response Surface Methodology with Central Composite Design was applied to minimize pesticides concentration by choosing the best soaking time and water:rice grain relation before cooking. A quadratic polynomial equation was obtained. Desirability function approach gave the optimal cooking conditions as 14 h soaking time and water:rice grain relation of 3. This process allowed a pesticide elimination of 100.0%, 93.5%, 98.4%, 98.5%, 99.0%, and 95.0%, of azoxystrobin, cyproconazole, deltamethrin, epoxiconazole, kresoxim-methyl and penconazole, respectively.

Determination, residue analysis, risk assessment and processing factors of tebufenozide in okra fruits under field conditions

BACKGROUND

Ensuring the yield, quality, and profitability of okra by preventing and controlling pests with the application of insecticides has increased in the last decade. Some insecticide residues might remain in edible parts of okra (fruits) and lead to several potential human health problems. Therefore, research on the residue behaviour, risk assessment and removal approach of insecticides on okra fruits is important for food safety, together with the proper application and residual elimination of insecticides in okra.

RESULTS

A simple liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was established and validated for determining the tebufenozide residues in okra fruits. The recoveries of tebufenozide in okra fruits were >72% with relative standard deviations of 0.6 to 6.1%. The dissipation rates of tebufenozide were different in okra fruits cultivated under open land and glasshouse field conditions because of the discriminating humidity and temperature conditions. The dietary intake of the tebufenozide residues from okra fruit consumption for Chinese consumers was fairly low, with approximately no potential health risk. The processing factor values of washing, blanching, washing + blanching and soaking were all less than one, which indicated that these processes could effectively reduce the residual hydrazide in the okra fruit.

CONCLUSION

The developed method for analysing tebufenozide in okra fruits was applicable for field studies on this insecticide. The potential health risk of tebufenozide in okra fruits could be negligible to the health of different age groups of Chinese consumers. The soaking process effectively removed tebufenozide residues from okra fruits. The obtained data will help Chinese governments establish a maximum residue limit of tebufenozide in okra and provide data for the risk assessment and removal of tebufenozide in other crops. © 2019 Society of Chemical Industry.

Effect of storage, washing, and cooking on the stability of five pesticides in edible fungi of Agaricus bisporus: A degradation kinetic study

Pesticide residue in food products is one of the most important global health challenges. The current study sought to investigate the changes in pesticides residue levels in Agaricus bisporus under different storage conditions and during washing and cooking. Pesticides analysis was performed using gas chromatography/mass spectrometry (GC-MS). The results showed that the half-life (t1/2) of all of the studied pesticides stored at room temperature was lower than refrigerator and freezer temperature. In addition, the greatest reduction of diazinon, malathion, permethrin, propargite, and fenpropathrin was found at a pH of 12, 2, 12, 7, and 9, respectively. Although sodium chloride had no effective impact on pesticide reduction during the same washing times, the removal of pesticides increased as washing time increased. Further, the reduction of pesticides was time-dependent during the boiling, microwaving, and frying processes. Based on these findings, the stability of insecticides, such as permethrin, malathion, and diazinon, was lower than acaricides, including propargite and fenpropathrin, in various techniques. Therefore, the use of washing solutions with an appropriate pH as well as increased cooking time may reduce the risk of pesticide exposure.

Neonicotinoids in raw, finished, and tap water from Wuhan, Central China: Assessment of human exposure potential

Neonicotinoid insecticides (NNIs) are emerging insecticides compared to organophosphates and pyrethroids. Their occurrence in the environment is not well documented in China. In this study, raw water samples (n=20), finished water samples (n=20), and tap water samples (n=165) originating from the Han River and the Yangtze River in Wuhan, Central China, were collected during 2018 for the determination of the NNI residues. NNIs were found in all raw water samples with a median sum concentration of 27.7ng/L (range: 13.4-186ng/L). Higher concentrations of NNIs were found in July than in May, and higher NNIs were found in the Han River than in the Yangtze River. Most NNIs were not effectively removed during water treatment, except for acetamiprid and thiacloprid which decreased by 40.1% and 20.0%, respectively. At least three NNIs were detected in all tap water samples with the highest sum concentration of NNIs observed in July (median: 96.2ng/L, range: 16.7-138ng/L) among the studied months (median: 15.4, range: 2.59-138ng/L). The estimated daily intake of NNIs via tap water ingestion in July was 8.66ng/kg body weight/day for infants, about 4 times higher than that for adults. The concentrations observed in tap water are elevated in China relative to previous studies that were conducted in the USA and in Canada. This is the first study reporting residue levels of NNIs in China.

Chlorfenapyr Residue in Sweet Persimmon from Farm to Table

The use of the pesticide chlorfenapyr has been increasing over time, with a consequent wider application to crops. However, there is limited information available on the amount and safety of the residues it leaves on crops. The amount of chlorfenapyr residues in sweet persimmon (Diospyros kaki L.) at both the pre- and postharvest stages were investigated in this study by calculating its biological half-life. The half-life at the preharvest stage was 8.8 days, shorter than that found during the storage periods at 4 and 20°C, when the half-lives were 11.0 and 23.9 days, respectively. In addition, peeling and washing after harvesting reduced residue content. The majority of the chlorfenapyr residues in sweet persimmon were found in the peel of the fruit, with the pulp containing less than 25% of the total. Thus, peeling effectively removed chlorfenapyr residues and diminished the residues below the limit of quantification in the pulp. In addition, washing with 1.0% alcohol and 0.2% Tween 20 solutions effectively removed 47.8 and 55.6% of the residues, respectively. Furthermore, a 1.0% alcohol solution showed high reduction efficiency for other hydrophobic pesticides, such as dimethomorph and fluquinconazole, up to 78.0%. Chlorfenapyr residues in sweet persimmon can be effectively reduced via storage or peeling and washing practices or a combination of them.

Assessing and Reporting Household Chemicals as a Novel Tool to Mitigate Pesticide Residues in Spinach (Spinacia oleracea)

Non-selective use of pesticide to increase productivity leaves residues on crops. These pesticides after consumption have a detrimental effect on human health and their intake can lead to various diseases such as kidney damage, neurological disorders, cardiovascular diseases, circulatory and reproductive problems. The recent study was designed to assess the effects of household processing treatments such as acidic solutions (acidic acid and citric acid), alkaline solutions (sodium chloride and sodium carbonate) and biological solutions (radish, ginger, garlic, and lemon extracts) were evaluated for their efficiency for removal of pesticides in spinach by gas chromatography with electron capture detector (GC-ECD). The results showed that pesticide residues were sharply reduced when spinach was exposed to washing treatments. The results showed that the greatest reduction of deltamethrin, cypermethrin, chlorpyrifos and endosulfan with 10% acetic acid was (79.68 ± 0.81%), (89.99 ± 0.12%), (94.21 ± 0.02%) and (70.32 ± 0.25%), respectively of tested washing solutions. The acidic solutions were more effective than alkaline and biological extracts in the removal of pesticide residues. The average reduction in various washing solutions ranged from 10.21 to 79.68%, 22.60 to 89.48%, 22.95 to 94-21% and 11.24–70.32% for the removal of deltamethrin, cypermethrin, chlorpyrifos, and endosulfan, respectively.

Dissipation, residues, and risk assessment of imidacloprid in Zizania latifolia and purple sweet potato under field conditions using LC-MS/MS

A shortened version of Quick, Easy, Cheap, Effective, Rugged, and Safe method (QuEChERS) for determining the dissipation and residue of imidacloprid present in Zizania latifolia and purple sweet potato was established by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The average recoveries of imidacloprid in the two crops ranged from 82.12 to 113.79%, with relative standard deviation (RSD) of <7.32%. The dissipation dynamics of imidacloprid in Z. latifolia plants and purple sweet potato plants followed first-order kinetics, with half-lives of 3.2-5.5 days in each of sampling locations. The terminal imidacloprid residues in Z. latifolia and purple sweet potato at each of location were <0.005-0.120 mg kg^-1. According to the risk assessment results, both the acute dietary risk quotient and chronic dietary risk quotient values were <1, indicating that imidacloprid is unlikely to pose health risks to humans with normal recommended use. The present study may serve as a valuable reference for the safe and reasonable use of imidacloprid in Z. latifolia and purple sweet potato fields.

Evaluation of various soaking agents as a novel tool for pesticide residues mitigation from cauliflower (Brassica oleracea var. botrytis)

The increasing use of pesticides for boosting the yield of agricultural crops also impart toxic residues which ultimately extend to numerous physiological disorders upon consumption. The present study was designed as an effort to assess the reduction potential of various chemical solutions and to minimize the pesticide residues in cauliflower (Brassica oleracea var. botrytis). The samples were soaked in various solutions along with tap water to mitigate pesticide residues. Afterwards, the extracted supernatant was passed through column containing anhydrous sodium sulfate trailed by activated carbon for clean-up. Eluents were first evaporated and then completely dried under gentle stream of Nitrogen. Finally, the residues were determined using gas chromatography equipped with electron capture detector (GC-ECD). Results revealed the highest reduction of endosulfan, bifenthrin and cypermethrin residues with acetic acid (10 %) was 1.133 ± 0.007 (41 %), 0.870 ± 0.022 (60 %) and 0.403 ± 0.003 (75 %), respectively among the tested solutions. However, simple tap water treatment also resulted in 0.990 ± 0.02 (12 %), 1.323 ± 0.015 (14 %) and 1.274 ± 0.002 (21 %) elimination of endosulfan, bifenthrin and cypermethrin residues, respectively. Moreover, among various solutions, acetic acid depicted maximum reduction potential followed by citric acid, hydrogen peroxide, sodium chloride and sodium carbonate solutions. The percent reduction by various solutions ranged from 12 to 41, 14 to 60 and 21 to 75 % for the elimination of endosulfan, bifenthrin and cypermethrin residues, respectively.