Search Results (3)

Rice straw is used as livestock feed and compost. Ferimzone and tricyclazole, common fungicides for rice blast control, can be found in high concentrations in rice straw after unmanned aerial vehicle (UAV) spraying, potentially affecting livestock and human health through pesticide residues. In this study, an optimized method for the analysis of the two fungicides in rice straw was developed using the improved QuEChERS method. After the optimization of water and solvent volume, extraction conditions including ethyl acetate (EtOAc), acetonitrile (MeCN), a mixed solvent, and MeCN containing 1% acetic acid were compared. Different salts, including unbuffered sodium chloride, citrate, and acetate buffer salts, were compared for partitioning. Among the preparation methods, the MeCN/EtOAc mixture with unbuffered salts showed the highest recovery rates (88.1–97.9%, RSD ≤ 5.1%). To address the severe matrix effect (%ME) of rice straw, which is characterized by low moisture content and cellulose-based complex matrices, samples were purified using 25 mg each of primary–secondary amine (PSA) and octadecylsilane (C₁₈), without pesticide loss. The developed method was validated with a limit of quantification (LOQ) of 0.005 mg/kg for target pesticides, and recovery rates at levels of 0.01, 0.1, and 2 mg/kg met the permissible range (82.3–98.9%, RSD ≤ 8.3%). The %ME ranged from −17.6% to −0.3%, indicating a negligible effect. This optimized method was subsequently applied to residue studies following multi-rotor spraying. Fungicides from all fields and treatment groups during harvest season did not exceed the maximum residue limits (MRLs) for livestock feed. This confirms that UAV spraying can be safely managed without causing excessive residues. Full article

Antifungals support modern medical and agricultural practices, and extensive screening environmental data are missing. This work aims to survey antifungals for medical and agricultural purposes in surface- and groundwater in Portugal. A passive sampling technique and a high-resolution chromatographic system were used. Antifungals applied in medical practice were not detected as only antifungals for agricultural purposes (fungicides). Thirty-nine different fungicide molecules were found; its detection frequency in surface- and groundwater was dominated by rabenzazole (61%, 92%) and ethoxyquin (54%, 77%); among the five fungicides with similar surface- and groundwater catching rates, ferimzone was the most polluting (54%, 54%); oxadixyl (61%), kresoxim-methyl (61%) and fenamidone (46%) were primarily designated surface water contaminants; for azoles, the occurrence in surface water ranged from a residual (10%) to a moderate detection rate for two compounds (31%—propiconazole and tebuconazole). Surprisingly, only 51% of detected fungicides are authorised. The frequently detected fungicides that are either not authorised (ethoxyquin and its impurity, furmecyclox, oxadixyl), without data in the EU (rabenzazole, ferimzone), or authorised at the national level (fenamidone), should be included in environmental monitoring programmes and followed as emerging (micro)contaminants. Policy makers should gather their efforts to allow the implementation of proper risk management and effective contamination control strategies to achieve Sustainable Development Goals. Full article

This study investigated the effect of milling on the yields of incurred residues extracted from cereals. Rice, wheat, barley, and oat were soaked in nine pesticides (acetamiprid, azoxystrobin, imidacloprid, ferimzone, etofenprox, tebufenozide, clothianidin, hexaconazole, and indoxacarb), dried, milled, and passed through sieves of various sizes. The quick, easy, cheap, effective, rugged, and safe method and liquid chromatography–tandem mass spectrometry extracted and quantified the incurred pesticides, respectively. For rice and oat, the yields were higher for vortexed samples than for soaked samples. For rice, the yields improved as the extraction time increased from 1 to 5 min. The optimized method was validated based on the selectivity, limit of quantitation, linearity, accuracy, precision, and the matrix effect. For rice and barley, the average yields improved as the particle size decreased from <10 mesh to >60 mesh. For 40–60-mesh wheat and oat, all pesticides (except tebufenozide in oat) had the highest yields. For cereals, 0.5 min vortexing, 5 min extraction, and >40-mesh particle size should be used to optimize incurred pesticide extraction. Full article