Simultaneous determination of pesticides from soils: a comparison between QuEChERS extraction and Dutch mini-Luke extraction methods

Herbicide contamination of Batak plain agricultural soils and risk assessment

Herbicide residue levels were analyzed in agricultural soils of Batak plain and health risk assessments were made for relevant pesticides. Herbicide contamination levels were analyzed with the use of Quick-Easy-Cheap-Efficient-Rugged-Safe (QuEChERS)-liquid chromatography/tandem mass spectrometry (LC-MS/MS) procedure. Herbicide-free soil samples were spiked at two different levels. Overall recovery of the method was 87.32%. Present findings were parallel to SANTE recovery limits. About 50% of collected samples from the study sites contained herbicides at different concentrations. Totally, eight herbicides were detected, and herbicide concentrations ranged between 1.085 and 1724.23 μg kg-1. Metolachlor had the highest concentration (1724.23 μg kg-1) in a sample taken close to the pesticide waste disposal area. Six herbicides were detected at different concentrations in the same sample. Persistent herbicides (terbuthylazine and pendimethalin) were detected in 35 samples. Risk assessments revealed that hazard index (HI) and hazard quotient (HQ) were less than 1. The greatest HQ values were identified for terbuthylazine as 2772.48 × 10-7 and 20793.61 × 10-7 for adults and children, respectively. The HI for all herbicides were 3916.05 × 10-7 for adult and 29370.39 × 10-7 for children.

Residue Behavior of Chiral Fungicide Prothioconazole and Its Major Chiral Metabolite in Flour Product Processing

This study systematically investigates the stereoselective metabolism and residue behavior of chiral pesticide prothioconazole enantiomers during the steaming, baking, and frying of steamed buns, bread, and deep-fried dough sticks. The results show that steaming, baking, and frying can significantly promote the degradation of the prothioconazole enantiomers. In low- and high-concentration treatments, the degradation rates of prothioconazole enantiomers were over 96.0% and 45.4%, respectively, and the residual concentration of prothioconazole-desthio enantiomers was less than 32.7 μg/kg (excluding fried processing). During the processing of steamed buns, bread, and deep-fried dough sticks, the enantiomer fraction (EF) value of the prothioconazole enantiomer was close to 0.5, and the stereoselectivity was not significant. During the processing of steamed buns (low concentration), bread (low and high concentrations), and deep-fried dough sticks (low concentration), the stereoselectivity of prothioconazole-desthio was significant, and preferential enantiomer degradation occurred. Following the analysis of 120 flour product samples, the residual risk.

Simultaneous determination of 27 pesticides in corn and cow matrices by ultra-performance liquid chromatography-tandem mass spectrometry

In this paper, we developed a sensitive UPLC-MS/MS method to determine pesticide residues in plant matrices (corn, fresh corn, fresh corn stover, old corn stover, and corn silage) and animal matrices (beef, fat, milk, milk fat, kidney, liver, and cow stomach) quantitatively. Twenty-seven pesticides were extracted with acetonitrile from all plant and animal matrices separately and purified with a mixture of primary secondary amine (PSA) and graphitized carbon black (GCB) or octadecylsilane (C18). The average recoveries of these compounds ranged from 60.7% to 118.2%, and the relative standard deviations were less than 20.0%. The limit of quantitation for all compounds was 0.01 mg kg-1 (for cyhalothrin and beta cypermethrin the LOQ was 0.02 mg kg-1). The establishment of multi-residue analysis methods for a variety of matrices can be used as a database for future method research. The results of this study are essential for calculating the transfer of pesticide residues from feed to animal products and for monitoring food safety, which will protect people's health and safety.

Establishing the extent of pesticide contamination in Irish agricultural soils

To establish meaningful and sustainable policy directives for sustainable pesticide use in agriculture, baseline knowledge of pesticide levels in soils is required. To address this, five pesticides and one metabolite widely used in Irish agriculture and five neonicotinoid compounds pesticides were screened from soils from 25 fields. These sites represented a diversity of soil and land use types. Prothioconazole was detected in 16 of the 18 sites where it had been recently applied, with the highest maximum concentration quantified of 46 μg/kg. However, a week after application only four fields had prothioconazole concentrations above the limit of quantification (LOQ). Fluroxypyr was applied in 11 sites but was not detected above LOQ. Glyphosate and AMPA were not detected. Interestingly, neonicotinoids were detected in 96% of all sampling sites, even though they were not reported as recently applied. Excluding neonicotinoids, 60% of sites were found to contain pesticide residues of compounds that were not previously applied, with boscalid and azoxystrobin detected in 15 of the 25 sites sampled. The total number of pesticides detected in Irish soils were significantly negatively correlated with clay fraction, while average pesticide concentrations were significantly positively correlated with log Kow values. 17 fields were found to have total pesticide concentrations in excess of 0.5 μg/kg, even when recently applied pesticides were removed from calculations. Theoretical consideration of quantified pesticides determined that azoxystrobin has high leaching risk, while boscalid, which was detected but not applied, has an accumulation risk. This information provides insight into the current level of pesticide contamination in Irish agricultural soil and contributes to the European-level effort to understand potential impacts of pesticide contamination in soil.

Analysis of Pesticide Levels in Honey and Pollen from Irish Honey Bee Colonies Using a Modified Dutch Mini-Luke Method with Gas and Liquid Chromatography-Tandem Mass Spectrometry Detection

Determining the levels of agrochemicals, such as pesticides, that honey bees are exposed to is critical for understanding what stress factors may be contributing to colony declines. Although several pesticide detection methods are available for honey, limited work has been conducted to adapt these methods for pollen. Here, we address this gap by modifying the Dutch mini-Luke extraction method (NL method) for pesticide analysis in honey and pollen from throughout the island of Ireland. The NL method was modified to enable detection in small-sized samples and validated for both pollen and honey matrices. The modified NL method combined with liquid and gas chromatography-tandem mass spectrometry gave consistent results in terms of accuracy and precision measured by recovery experiments and was successfully applied in the analysis of a range of pesticide residues. The modified NL method developed here provides a key tool for detecting pesticides in honey bee colony resources and the environment more broadly.

Determination of fungicide residues in soil using QuEChERS coupled with LC-MS/MS, and environmental risk assessment

Fungicide residues of soil samples taken from Batak Plain of Çanakkale province of Türkiye were assessed. Fungicide residue analyses were performed with the use of QuEChERS method and LC-MS/MS device. Blank samples were spiked at two different limit of quantification (LOQ) levels for method verification. Overall recovery was identified as 85.69% with an RSD of 12.36% (n=360; SD=10.59). A total of 110 soil samples were taken in November 2020. Present analyses revealed that 59.09% of samples contained fungicide residues at different concentrations. Propiconazole had the highest concentration (1736.06 μg/kg) in one sample, taken from the edge of the field where pesticide wastes were found and 26 fungicides were found at different concentrations in the same sample. Azoxystrobin was encountered in majority of the samples (29 samples). The most frequent fungicides were ordered as; boscalid and tebuconazole (22 samples) > metalaxyl (17 samples) > fluopyram (15 samples). Thirteen triazole fungicides were found in soil samples, mostly at moderately hazardous level (Class II). Risk assessments revealed that hazard levels of fungicides for adults and children were low with a hazard quotient (HQ) and hazard index (HI) of <1. Despite the safe nature of fungicides in soil samples, the greatest HQ values were identified for propiconazole (326.52E-08 for adults and 2449.00E-08 for children). The sum of hazard quotients for all fungicides was 86.31E-08 8 for adult and 647.35E-08 for children. In terms of soil pollution, it is important for farmers to apply fungicides with low HQ levels.

Monitoring and environmental risk assessment of agricultural fungicide and insecticides in water, sediment from Kumkale Plain, Çanakkale-Turkey

This study was conducted to assess pesticide residues in 34 water and sediment samples taken from Kumkale Plain of Çanakkale-Turkey. Residue analyses were performed with the use of Quick-Easy-Cheap-Efficient-Rugged-Safe (QuEChERS)-liquid chromatography/tandem mass spectrometry (LC-MS/MS) procedure. For method verification, blank sediment and water samples were spiked at two limits of quantification (LOQ) levels of the pesticides. Overall recovery was 81.66% for sediment and 91.50% for water samples. In sediment samples, chlorpyrifos-M had the highest concentration, pyridaben was encountered in the majority of the samples (15 samples) and the highest number of pesticides (35) was seen in sample no. s13. In water samples, methoxyfenozide had the greatest concentration, metalaxyl was encountered in the highest number of samples (three samples) and the highest number of pesticide (8) was seen in sample no.w13. Sample no. s13 and w13 were taken from around the fountain basin. Pyraclostrobin and chlorantraniliprole residues exceeded the national limits set for water. In terms of hazard quotient (HQ), pesticides in sediment and waters were found to be safe. Despite the safe nature of pesticide on samples, greater attention has been paid on toxicity of the residues. It was concluded that authorities should put strict regulations on agrochemicals to reduce health risks of these chemicals.

Simultaneous determination of glyphosate, glufosinate ammonium and their metabolites in maize and soybean by ultra-performance liquid chromatography with tandem mass spectrometry

Glyphosate and glufosinate ammonium are non-selective, broad spectrum herbicides for controlling grasses in agriculture and forestry. Rapid and sensitive analytical methods for effective monitoring and subsequent risk control of glyphosate and glufosinate ammonium and their metabolites in crops are not available. In this paper, an analytical method for the simultaneous determination of glyphosate, glufosinate ammonium, and their metabolites in maize and soybean by ultra-performance liquid chromatography with tandem mass spectrometry was established. The seven compounds were well separated on an anion exchange analytical column within 10 min, with the mean recoveries of the target compounds ranging from 78.2 to 110.9%. The method showed good linearity (R² ≥ 0.9819) with a limit of quantification for glyphosate, glufosinate ammonium, and their metabolites of 0.01 mg kg^-1 in both maize and soybean. The method simplifies and expedites the sample preparation procedures, overcomes the traditional disadvantages including derivatization, weak retention, and low sensitivity, and has been successfully validated in actual maize and soybean samples.