Transfer Behavior of Carbendazim from Dried Yingshan Yunwu Tea Leaves into Tea Infusions

Tea infusion is the main route of human exposure to pollutants in tea,and it is vital to investigate the transfer rate of pollutants from tea leaves to infusion.Carbendazim is a commonly used systemic fungicide,the transfer behavior of which in Yingshan Yunwu tea is not clear.Hence,this study firstly established the analytical method for determination of carbendazim with great accuracy and precision via modified QuEChERS method and ultra-performance liquid chromatography-fluorescence detection(UPLC-FLD).Then,the transfer behavior of carbendazim from tea leaves and infusion was systematically investigated.Results indicated that water temperature and proportion of tea to water ration would obviously increase the transfer rate of carbendazim,but times of infusion repetition showed negative correlation with the transfer rate of carbendazim.In addition,brewing time seemed to have lesser impact on the transfer rate.This study will be helpful for the risk assessment of carbendazim residue and provide the guidance for tea brewing.

Effects of Househould Cleaning Methods on Carbendazim Residue in Apples

Carbendazim,belonging to fungicides,was commonly used for controlling crop diseases,resulting in frequent residues in fruits and vegetables.Washing was the initial step of household fruit processing for cleaning and reducing pollutant contents.However,the effect of washing on the removal of carbendazim in apples was not systemically studied.Thus,in this study,an analytical method was firstly established for the determination of carbendazim with great accuracy and precision through quick,simple,cheap,effective and safe(QuEChERS)method and ultra-performance liquid chromatography-fluorescence detection(UPLC-FLD).Then,the influencing factors were systematically researched to unveil their effects on the carbendazim residue in apples.The results indicated that water temperature,washing products and washing method could obviously affect the carbendazim content in apples.In addition,the best cleaning scheme for removal of carbendazim was soaking apples for 5 min in a cleaning solution,which was prepared by dissolving 8 g of commercial fruit washing soup with 500 ml of water at 45℃.Under this condition,the removal rate of carbendazim in the washing step reached 73.91%.This study will be helpful for providing guidance for household cleaning methods for controlling pesticide residues.

Residues of High Concentration Carbendazim on Plants in Natural State

[ Objective] The paper was to explore the residual dynamics and degradation rule of high concentration carbendazim in natural condition. [ Method J The earbendasim solutions with mass fractions of 0.2% （ recommended concentration）, 0.4% （2 times of the recommended concentration） and I. 0% （5 times of the recommended concentration） were sprayed on plant leaves, and the residual amount of earbendazim in natural condition was determined. The dynamic models of carbendazim residues Under 3 concentrations were also studied. [ Result~ The degradation of earbcndazim under recommended concentration was accorded with Kinetic model for degradation, but the degradation Kinetic model for samples under 2 times and 5 times concentration appeared dissimilation. The residue of carben- dazim on plant was affected by absorption capacity of plants and weather conditions. The absorption capacity was affected by application concentration and growth condition of plant, higher concentration application and slow growth stage of p]ant were not conducive to the absorption of carbendazim; weather condition was mainly referred to temperature and humidity, higher temperature and dry weather were not conducive to the degradation of earbendazim. [Condusion ] The paper provided theoretical basis for guiding the application of carbendazim under different growth stages of crops and different weather conditions in agricultural production.

Isolation of Carbendazim-degrading Bacterium XJ-D and Analysis on Its Characteristics

[Objective] The aim was to isolate the Carbendazim-degrading bacterium, so as to provide reference for the bioremediation of carbendazim contaminated soil. [Method] A carbendazim-degrading bacterium was isolated from a vineyard which has been applied with carbendazim for a long term; then the strain was identified using Biolog automatic analysis system and phylogenetic analysis based on 16S rDNA sequence. [Result] The strain XJ-D was identified as Rhodococcus erythropolis. It can use carbendazim as the sole carbon or nitrogen source, and degrade 99.0% of carbendazim at concentrations of 600 mg/L in mineral salt medium within 11 d. In addition, it showed a high average degradation rate of 52.87 mg/（L·d）. [Conclusion] The carbendazim-degrading bacterium XJ-D has a wide application prospect in bioremediation of pesticide-polluted soil.

Effects of chlorothalonil and carbendazim on nitrification and denitrification in soils

The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. Laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.

Carbendazim sensitivity in populations of Colletotrichum gloeosporioides complex infecting strawberry and yams in Hubei Province of China

The ascomycete fungus Colletotrichum gloeosporioides is a devastating plant pathogen with a wide host range and worldwide distribution. Carbendazim has been widely used to control anthracnose caused by the C. gloeosporioides complex in China for more than 30 years and resistance to carbendazim has been reported in China. A total of 125 Colletotrichum isolates of strawberry and yam were collected from different geographical regions in Hubei Province, China. Approximately 52.8％ of Colletotrichum spp. isolates showed resistance to carbendazim. The isolates tested in this study belong to four species, and the frequencies of resistant isolates differed across Colletotrichum species. Resistant isolates were found in C. siamense and C. fructicola. In contrast, all isolates of C. gloeosporioides and C. aenigma were sensitive to carbendazim. Highly carbendazim-resistant isolates harbored the E198A mutation in the β-tubulin 2 （TUB2） gene, whereas moderately carbendazim-resistant isolates harbored the F200Y mutation in the TUB2 gene. Carbendazim-sensitive Colletotrichum isolates in this study were not genetically similar enough to form a separate cluster from resistant isolates. The result of this study emphasizes the importance of knowing which Colletotrichum sp. is present, when strategies for disease control are made.

Effects of repeated applications of fungicide carbendazim on its persistence and microbial community in soil

Carbendazim, a systemic benzimidazole fungicide, is applied repeatedly to control plant diseases including soilborne diseases, over a growing season. Studies were carried out under laboratory conditions to assess the effects of repeated carbendazim applications on its persistence and microbial community in soil. The results indicate that dissipation of carbendazim in soil was accelerated with its application frequency. The degradation rate constant of carbendazim was increased significantly from 0.074 d-1 to 0.79 d-1. The corresponding half-life was shorten markedly from 9.3 d to 0.9 d after four repeated applications. No significant inhibitory effect of carbendazim on soil microbial utilization of the carbon sources was observed after first treatment, but a slight increase in average well color development （AWCD） was shown after second, third, and fourth applications. It suggested that soil microorganisms become adapted to carbendazim after repeated application. Simpson and Shannon indexes of soil microbial community from carbendazim treated soil were also similar to those from the control soil, indicating that the richness and dominant character of soil microorganisms remain unchangeable after repeated application. However, after first, second, and third addition of carbendazim, McIntosh indexes on day 21 were significantly higher compared with the control, suggesting that balance of soil microorganisms was altered due to the enrichment of the specific carbendazim-adapting strains in soil

Carbendazim induces a temporary change in soil bacterial community structure

The effect of carbendazim applications on the diversity and structure of a soil bacterial community was studied under field conditions using temperature gradient gel electrophoresis （TGGE） and partial sequence analysis of PCR-amplified 16S rRNA gene. After four successive introductions of carbendazim at a level of 0.94 kg active ingredient （a.i.）/ha, the genetic diversity （expressed as Shannon index, H′） decreased from 1.43 in the control to 1.29 in treated soil. This harmful effect seems to increase with the concentration of carbendazim. The value of H＇ in the soil treated with carbendazim at 4.70 kg a.i./ha was reduced to 1.05 （P ≤ 0.05）. The structure of soil bacterial community was also affected after four repeated applications of carbendazim at levels of 0.94, 1.88 and 4.70 kg a.i./ha, as seen in the relative intensities of the individual band. However, the bacterial community in carbendazim-treated soil recovered to that in the control 360 d after the first treatment. The results indicated that repeated applications of carbendazim could reduce soil microbial diversity and alter the bacterial community structure temporarily.

Sensitivity of Fusarium graminearum to Carbendazim and Prochloraz

[ Objective] The paper was to understand the resistance of Fusarium graminearum to carbendazim and prochloraz in the main wheat producing areas in Hubei Province. [ Method] Totally 350 F. graminearum strains isolated in 2014 were determined to clear their sensitivity to carbendazim and prochloraz. [ Result] ALl isolates were sensitive to carbendazim and procidoraz in Hubei Province, and carbendazim was still valuable in controlling Fusarium head blight. The control effect of prochloraz was better than that of carbendazim, and the combination of prochloraz and carbendazim at the proportion of 1：7 received the best control effect. [ Conclusion ] Combination of chemical agents will occupy a more and more important position in future prevention and control against Fusarium head blight.

Protective Effect of <i>Gingo biloba</i>Extract on Carbendazim-Induced Hepatotoxicity in Albino Rats

Carbendazim is a broad spectrum carbamate fungicide used in the control of various fungal pathogens. The present work studied the effect of carbendazim on the liver of albino rats and the possible protective role of Ginko biloba extract (EGB). Liver of carbendazim-treated animals showed histopathological and histochemical alterations. The histopathological changes include hepatic tissue impairment, cytoplasmic vacuolization of the hepatocytes, and congestion of blood vessels, leucocytic infiltrations and fatty infiltration. Histochemical results showed reduction of carbohydrates and total proteins in hepatic tissues. Moreover, liver function enzymes (ALT, AST) were elevated in sera of carbendazim-treated animals. Coadministration of EGB with Carbendazim improved the hisological and histochemical changes observed in animals treated with carbendazim. In addition, EGB treatment leads to a significant decrease in ALT and AST. According to the present results, it is concluded that EGB can improve the hepatotoxicity of carbendazim and this effect may be attributed to antioxidant properties of Ginko biloba extract.

RESISTANCE OF SCLEROTINIA SCLEROTIORUM TO CARBENDAZIM

This study covers the observation of the factors which influence the resistance development of S. sclerotiorum to carbendazim, the comparison betweeen normal course of infection and infection of hosts by a strain of S. sclerotiorum when resistance to carbendazim has been developed.

RESISTANCE OF SCLEROTINIA SCLEROTIORUM TO CARBENDAZIM Ⅰ. Resistance and Its Development of Sclerotina Sclerotiorum to Carbendazim

This paper covers the examination of EC50 of carbendazim to diferent isolates of S. sclerotiorum, the observation of the resistance development in a population of the pathogen,for working out whether carbendazim plays some role in increasing the resistance of the fungus to the chemical.

Control Efficiency of 36% Carbendazim Triadimefon SC on Wheat Powdery Mildew and Pink Mold

This paper explored the control efficiency of 36% Carbendazim triadimefon SC on wheat powdery mildew, wheat pink mold and rope sclerotinia, and the impact on rape yield through field experiment. The results showed that the control efficiency was the best on the 7th and 14th day after the application of 36% Car- bendazim triadimefon SC in the dosage of 2 250 mL/hm2, and rope yield was improved by 32%.

Carbendazim resistance and calculation effective concentration of carbendazim for Trichoderma harzianum

There is a method for investigating the transformation of resistance gene of carbendazim into Trichoderma harzianum. In order to introduce the resistance to benzimidazole fungicide into bio-control microorganism Trichoderma harzianum was transformed with the resistance gene. In this study, we investigate resistance level and calculate EC 50 (effective concentration of carbendazim that can survive 50% of Trichoderma harzianum in that concentration) and stability of the resistance for the transformant isolate of Trichoderma harzianum. Results show the transformants can growth on the medium containing more than 1 000 μg/ml carbendazim and the resistance is stabled after 10 times transfer on non-selective medium and have EC 50 average about, 1 200 μg/ml.

Rapid detection of the E198A mutation of carbendazim-resistant isolates in Colletotrichum gloeosporioides by loop-mediated isothermal amplification

Apple bitter rot is a serious agricultural disease caused by Colletotrichum gloeosporioides.In recent years,carbendazim-resistant C.gloeosporioides strains bearing an E198A point mutation in theβ-tubulin gene(GAG to GCG)have emerged,threatening global apple production.As such,rapidly detecting the presence of this E198Amutation in C.gloeosporioides isolates is essential in order to monitor the spread of this pathogen and to prevent outbreaks of disease.Herein,we developed a simple loop-mediated isothermal amplification(LAMP)approach to detecting the E198A mutation in C.gloeosporioides isolates from‘Gala’apple samples.This optimized LAMP protocol was sufficient to establish the E198A genotype of a given isolate following a 60min incubation at 63℃ by using four specific primers.The results of this reaction could be interpreted visually based on a fluorescent yellow-green color change upon the addition of the SYBR Green I dye,and were additionally confirmed via gel electrophoresis.Importantly,this LAMP assay was capable of rapidly and reliably detecting apples that were infected with carbendazim-resistant isolates harboring this E198A mutation.In conclusion,this LAMP assay in this study can rapidly,specifically,and sensitively detect cases of apple bitter rot caused by C.gloeosporioides isolates harboring the E198A mutation.

Spectrofluorimetric Analysis of the Fungicide Carbendazim and Its Metabolite 2-Aminobenzimidazole in Natural Water

A spectrofluorimetric method for the direct analysis of carbendazim [methyl 2-benzimidazole carbamate (MBC)] fungicide and its metabolite 2-aminobenzimidazole (2-AB) in natural waters is described. Very low limit of detection (LOD) and limit of quantification (LOQ) values of 0.002 - 0.06 ng/mL and 0.006 - 0.2 ng/mL, respectively, were determined by spectrofluorimetric method with small relative standard deviation (RSD) values < 1%. This spectrofluorimetric method was applied to the determination of MBC and 2-AB residues in natural waters, with satisfactory recovery values of (88.5% - 119.2%).

Carbendazim residue in plant-based foods in China:Consecutive surveys from 2011 to 2020

Carbendazim,a widely used fungicide in China,has been found to have reproductive toxicity and mutagenic effects.However,information on the spatial-temporal variations of carbendazim residues in food in China is limited.Here,we investigated the presence of carbendazim in China's plant-based foods from 2011 to 2020,evaluated the spatial-temporal characteristics,and assessed the associated exposure risks in the Chinese diet.The results revealed a high detection frequency of carbendazim in fruits(26.4%)and high concentrations in vegetables(~110 mg kg^(-1)),indicating widespread misuse of the fungicide.The acute risks of consuming certain vegetables and cereals exceeded the recommended limits by up to 12 and 5 times,respectively.Although there has been a decline in carbendazim residue levels in food since the implementation of the Chinese government's action plan for zero growth of pesticide use in 2015,some provinces still exhibited high levels of carbendazim in multiple food categories,which were positively correlated with annual pesticide application.We highlight that carbendazim contamination reflects the broader issue of pesticide use in China.It emphasizes the need for committed and targeted national policies to reduce carbendazim residues in food and suggests that such measures could also regulate the use of other pesticides,given that pesticide abuse in China is not limited to specific types.We call for the re-evaluation of maximum residue limits of carbendazim,particularly in highly consumed foods such as cereals.

HPLC及LC-MS测定榛子中氯吡苯脲和多菌灵残留

本文采用高效液相色谱法(HPLC)和液相色谱-质谱法(LC-MS)对干果榛子中氯吡苯脲和多菌灵残留量进行含量测定.HPLC和LC-MS均使用C18色谱柱,含量测定采取等度洗脱,流动相:甲醇-水(55∶45,体积比);体积流量:1.0 mL·min-1;测定波长:260 nm;柱温:30℃.LC-MS采取电喷雾离子源,梯度洗脱,体积流量:0.6 mL·min-1,柱温:30℃.结果表明,榛子中氯吡苯脲与多菌灵存在残留,氯吡苯脲质量浓度在1.00~10.00μg·mL-1范围内线性关系良好,加样回收率在95.58%~100.58%;多菌灵质量浓度在1.005~15.075μg·mL-1范围内具有良好的线性关系,加样回收率在95.61%~104.39%.实验证明,HPLC与LC-MS相结合的方法具有操作简便、灵敏度高、检出限低等优点,能有效地检测到榛子样品中膨大剂氯吡苯脲及杀菌剂多菌灵的残留,并确定其残留量,线性关系和回收率结果均令人满意.根据被检测的8批样品中氯吡苯脲和多菌灵两项农药残留量推断,作为一般干果食用榛子是安全的.

基于太赫兹成像技术的茶叶基质表面多菌灵农残分布与检测分析

采用太赫兹(THz)成像技术实现茶叶复杂基质上多菌灵定位及质量浓度分析.首先提取多菌灵压片THz光谱,得到位于1.15 THz和1.32 THz处的特征吸收峰,证明了太赫兹光谱检测多菌灵成分的有效性.其次,对比不同茶叶基质上多菌灵成像效果,确定最佳样本制备条件;制备800,1700,2300,3000,3700,4500,5000 mg/L 7个不同质量浓度的茶叶农残样本,采用时域切片法,选择时间延迟为13.98 ps进行成像,并进行超分辨率重建,实现多菌灵区域精确定位.鉴于THz叶片图像难以获得参考图像,采用自然图像质量评价(NIQE)、基于空间和光谱熵的无参考图像评估(SSEQ)和无参考空间域质量评估(BRISQUE)3种评价方法对重建前后的图像进行质量评估.结果表明,重建得到的图像评分更优,可以有效提高图像分辨率.最后,采用图像分割算法提取农残分布区域,建立光谱透射强度与农药质量浓度的关系方程,实现多菌灵定量分析.

基于Au@4-ATP@Au凸多面纳米颗粒的多菌灵表面增强拉曼散射检测

表面增强拉曼散射(SERS)技术在农药残留的检测方面具有很大的潜力,但在痕量和定量分析方面仍存在局限性。提出了一种基于Au@4-ATP@Au凸多面纳米颗粒(NCPs-Au@4-ATP@Au)为增强基底的农药检测方法。XRD结果表明,由于探针分子对金前驱的选择性和诱导性,NCPs-Au@4-ATP@Au纳米颗粒与球形金纳米颗粒晶面结构信息有明显差异,具体体现在(200)处的强反射峰。结合扫描电镜与吸收光谱可以确定,NCPs-Au@4-ATP@Au同时具备球形与多面体结构特征。吸收峰较球形金纳米颗粒有明显红移,更加接近激发光波长,这在理论上更有利于SERS信号的增强。实验证明,以表面包覆高指数晶面,同时内嵌4-ATP作为探针分子的NCPs-Au@4-ATP@Au为增强基底,农药多菌灵(CBZ)的检测限(LODs)达到0.66 nmol·L^(-1)。通过对CBZ分子的拉曼与SERS光谱位移分析可以初步确定,CBZ分子是通过NH键和CO键吸附于金纳米颗粒上。Au@4-ATP@Au利用多凸面结构体提高灵敏度的同时,以4-ATP作为定标信号,归一后光谱稳定性和时效性也得到改善。内标峰强度矫正后光谱稳定性的相对标准偏差(relative standard deviation,RSD)低至7.03%,半个月内信号强度仅降低5.87%,RSD为2.94%。结果表明,NCPs-Au@4-ATP@Au提高了SERS在农药检测方面的痕量和定量检测能力,该基底有望推动SERS在实际中的应用。