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[会议论文 ] Analysis of Tea pesticide residue standards and testing methods 进入全文
6th International Conference MMEBC 会议
Tea has always been China's traditional agricultural crops, and is one of a large number of agricultural exports. However, in recent years, China's tea exports encountered the biggest problem is pesticide residues, developed countries or regions to limit pesticide residues in tea standards have hindered the development of China's tea exports. Aiming Situation to Analysis and Research of China's tea exports to China tea pesticide residue limits with the European Union, Japan, the United States and other developed countries or regions as well as the United Nations Food Codex Committee on Pesticide Residues (CODEX) differences tea pesticide residue limits exist, this article proposed more specific response. At the same time, through the analysis of pesticide residues in tea different methods and control measures, to improve the tea pesticide residue standards, source control, and improve tea security, we made recommendations to make China's tea product quality and international standards as soon as possible.
[学术文献 ] Comprehensive insights into pesticide residue dynamics: unraveling impact and management 进入全文
Chemical and Biological Technologies in Agriculture 期刊
The imperative use of pesticides for enhancing agricultural productivity has become inevitable. Unfortunately, the unregulated and indiscriminate application of these pesticides extends beyond the intended target areas, with residues persisting for months to even years. This lack of precision and information has triggered widespread pest outbreaks, posing significant health risks to both humans and other organisms due to pesticide residues in food. The presence of even trace amounts of these residues has emerged as a major impediment to international trade in food commodities. To address these challenges and align with sustainable practices, the article highlights the urgent need for controlled pesticide techniques, including organic farming, safe harvest indices, and bioremediation, which are crucial aspects of mitigating admixed micropollutants in the environment. The discussion covers the impact of pesticides on food quality, effective residue management, and the vital role of regulatory bodies. Drawing from diverse sources, the work seeks to provide a concise yet comprehensive overview and solutions to the challenges of pesticide management.
[相关专利 ] METHOD AND SYSTEM FOR DETECTING PESTICIDE RESIDUES IN TEA BASED ON SURFACE-ENHANSED RAMAN SCATTERING (SERS) SENSOR 进入全文
美国专利
一种基于SERS传感器的茶叶农药残留检测方法及系统。制备八面体金银空心笼基传感器，与农药标准溶液混合后分析得到SERS光谱数据。对所述SERS光谱数据进行处理，并根据处理后的SERS光谱数据建立定量模型。基于定量模型，可完成茶叶样品中福美双和吡蚜酮的检测。利用八面体氧化亚铜模板，通过还原金银离子和酸溶去除模板制备金银八面体空心笼(Au-AgOHCs)纳米材料，制备SERS传感器，可应用于茶叶样品中福美双和吡蚜酮的快速定量检测。
[学术文献 ] Identification of key factors affecting neonicotinoid residues in crops and risk of dietary exposure 进入全文
Environmental Pollution 期刊
Neonicotinoids, widely used on farmland, are ubiquitous in food; however, their distribution among various crops and associated exposure risks at the provincial level in China remain unclear. We collected 19 types of crop samples (fruits, vegetables, and tea) from farmland in nine prefectural cities in Zhejiang Province, China. We analyzed nine commonly used neonicotinoids in the edible portions of these crops. A notable detection rate (42.1 %–82.9 %) and high residual neonicotinoid concentrations (278 ± 357 ng/g) were observed. Tea exhibited the highest residue, followed by fruits, and vegetables showed the lowest (P < 0.05). Neonicotinoid ratios in crops to soil (R_C/S) and soil to water (R_S/W) were defined to discern insecticide distribution across different environments. Increased water solubility leads to increased migration of neonicotinoids (R_S/W) from agricultural soils to water through runoff, thereby increasing the relative contribution of nitenpyram and dinotefuran in water. In comparison with other studied compounds, all crops demonstrated the strongest soil uptake of thiamethoxam, denoted by the highest R_C/S value. Elevated R_C/S values in tea, pickled cabbage, and celery suggest increased susceptibility of these crops to neonicotinoid absorption from the soil (P < 0.05). Estimated dietary intake for teenagers, adults and elders was 8.9 ± 0.5, 8.9 ± 0.6, and 8.8 ± 0.3 μg/kg/d, respectively, below the reference dose (57 μg/kg/d). Teenagers, compared to adults and elders, exhibited significantly higher neonicotinoid exposure through fruit consumption, emphasizing the need for increased attention to neonicotinoid exposure among vulnerable populations.
[学术文献 ] Phenolic-based non-ionic deep eutectic solvent for rapid determination of water soluble neonicotinoid insecticides in tea infusion 进入全文
Food Chemistry 期刊
Challenges were raised to established analytical method for monitoring water soluble neonicotinoid insecticide (NEOs) residues in tea infusion. Phenolic-based non-ionic deep eutectic solvent (NIDES) composed by a mixture of DL-menthol and thymol (molar ratio of 1:3) was applied to achieve the determination of selected NEOs. Factors influenced extraction efficiency have been evaluated and molecular dynamics approach was conducted aming to provide a new insight to explain its extraction mechanism. It is found that Boltzmann averaged solvation energy of NEOs was negatively correlated with extraction efficiency. The method validation results indicated good linearities (R2 ≥ 0.99), sensitive LOQs (0.05 μg L-1), high precisions (RSD < 11%) and satisfactory recoveries (57.7%∼98%) at 0.05 μg L−1 ∼ 100 μg L−1. The intake risk of NEOs in tea infusion samples were acceptable which residues in range of 0.1 μg L-1 ∼ 3.5 μg L-1 for thiamethoxam imidacloprid and thiacloprid. This method showed advantages of rapid, green, and easy operation.
[学术文献 ] Neonicotinoid residues in commercial Japanese tea leaves produced by organic and conventional farming methods 进入全文
Toxicology Reports 期刊
The current study sought to assess the residual levels of neonicotinoid insecticides (NEO) in organic and conventional green tea leaves produced in Japan. A total of 103 tea leaves (thus, 42 organic and 61 conventional), were sampled from grocery stores in Japan. Concentrations of NEOs in the tea leaves were quantified using LC–MS/MS; and the data was used to estimate maximum daily intakes of NEOs within the Japanese population. Seven native NEO compounds and one NEO metabolite were detected in both organic and conventional tea leaves. Detection frequencies (%Dfs) of NEOs in the tea samples (n = 103) were found in the decreasing order; thiacloprid (84.47 %) > dinotefuran (74.76 %) > imidacloprid (69.90 %) ≈ clothianidin (69.90 %) > dm-acetamiprid (63.11 %) > thiamethoxam (58.25 %) > acetamiprid (4.85 %) > nitenpyram (1.94 %). About 94.20 % of the tea leaves contained two or more NEO compounds simultaneously. The %Dfs of NEOs were relatively lower in organic tea leaves, compared to the conventional tea leaves. Various percentile concentrations of NEOs were far lower in organic tea leaves, compared to the conventional tea leaves. The maximum daily intakes of NEOs through consumption of tea (MDIgt) were also lower for organic tea leaves, compared to the conventional tea samples.
