果蔬农药残留危害及预防控制措施

论述了农药残留的现状及其危害,分析了造成农药残留污染严重的原因,提出了具有针对性的解决方法。

Simultaneous Determination of Four Pesticide Residues in Fruit Juice by HPLC

[Objective] This study was conducted to develop a system for simultaneous determination of imidacloprid, diflubenzuron, thiabendazole and carbendazim in fruit juice by HPLC. [Method] Using acetonitrile as the extraction solvent, the pesticides in fruit juice were purified through a NH2 solid phase extraction （SPE） cartridge, then detected by HPLC. [Result] There was a good linear relationship between the peak area and the concentrations of imidacloprid, diflubenzuron, thiabendazole and carbendazim in a range of 0.05-5.0 μg/ml, and the linear correlation coefficient varied in a range of 0.999 0-0.999 8; the limit of detection for imidacloprid, diflubenzuron, thiabendazole and carbendazim was 0.003, 0.005, 0.003 and 0.007 mg/kg, respectively. The recovery rate of imidacloprid, diflubenzuron, thiabendazole and carbendazim standards added at three levels （0.1, 0.5 and 1.0 mg/kg） ranged from 82% to 107%, with RSD less than 4.5%. [Conclusion] The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.

Determination of 2 Amides Pesticide Residues in Agricultural Products by Terahertz Time-domain Spectroscopy

[Objective] The aim was to explore the application of terahertz （THz） technique in pesticide recognition and residue determination. [Method] THz far-infrared spectral characteristics of 2 herbicides （butachlor and metolachlor） were measured by THz time-domain spectroscopy （THz-TDS） under conditions of room temperature and nitrogen,meanwhile their refractive index and absorption coefficient between 0.2 and 2.2 THz were calculated by using models based on Fresenl equations. [Result] The 2 pesticides both had a series of different characteristic absorption peaks between 0.2 and 2.2 THz,respectively. Their molecular structures were similar,but there were great difference in absorption and refractive index spectrum between them. [Conclusion] THz-TDS technique is feasible to detect pesticide residues,especially there is a greater advantage in identifying the structure of similar substances.

Investigation and Analysis of Pesticide Residues in Citrus from Parts of Hubei Province

The analysis of pesticide residues in Citrus from Yichang, Danjiangkou, Zigui and Xingshan in Hubei Province was accomplished by UPLC-MS and GC-MS. The results showed that the detection rate of pesticide residues in Citrus reticulate was 91.9%. The detection rate of banned pesticides was 1.6%. The detection rate of restricted pesticides was 9.5%. The detection rate of allowed pesticides was 68.3%. The detection rate of unregistered pesticides was 15.9%. The pesticide used in citrus was relatively common. Because of the banned and restricted pesticides were both in the control degree, on the whole, the quality and security of Citrus reticulata was safe.

Study on Detection of Organochlorine Pesticide Residue in Ginseng

To investigate the residue situation of pesticides in ginseng, total 17 samples of ginseng-growing soil, ginseng roots and ginseng seeds were collected from 5 regions of Fusong County, and the contents of organochlorine pesticide residues in the samples were detected by using ultrasonic-assisted extraction and gas chromatography with acetone-ligroin as the solvent, thereby providing suitable recommendations and scientific basis for the selection of ginseng-growing soil.

Determination of 10 Pyrethroids Pesticide Residues in Rice by GC-MS-MS

[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.

Usage of Pesticides and Control Measures in Qujing City

[Objective] The aim was to investigate pesticide use in Qujing city and explore the control measures.[Method] Surveys were made on pesticide use by farmers in five vegetable bases in Qujing city by questionnaires to study pesticide use and existing problems by farmers.[Result] Some problems existed in pesticide use in Qujing,such as non-standard pesticide source,lower-recognition of pesticide and impacts of pesticide residues on environment,and without professional guidance.[Conclusion] The existing problems can be resolved by enhancing technical trainings of technicians or pesticide managers,strengthening pesticide promotion,and reinforcing examination of pesticide residues.

Study on Pesticide Residues of Phorate and Emamectin Benzoate in Cauliflower with Ball Well Protected

In order to study the difference between cauliflower varieties with ball well protected and unprotected in terms of pesticide residue and its causes, Jinpin 70, a new male sterile cauliflower variety with ball well protected, and Xuebao with ball unprotected were sprayed with high-toxic pesticide phorate and efficient bio-pesticide emamectin benzoate at a regular dose to investigate the impact of different cauliflower varieties on the pesticide residue. The results showed that from the 3rd to the 5th day after spraying, phorate and emamectin benzoate residues in Jinpin 70 with ball well protected reduced by 76.47%-87.65% and 67.86%-80.82% re- spectively compared with Xubao, and decreased by 9.23%-81.82% and 57.14%- 79.84% respectively compared with Jinpin 70 with ball unprotected. The results above demonstrates that inner leaves of cauliflower with ball well protected can prevent the ball from being polluted by phorate and emamectin benzoate, thereby improving its edible safety.

Study on Prediction of Pesticide Residues Based on Fuzzy System

This study was aimed to do the prediction of pesticide residues based on fuzzy system. Taking chlorpyrifos as an example, the Mathematic Fuzzy System was established by using the MRL values （maximum residue limits of all kinds of pesticides in food） of the Matlab Fuzzy Toolbox to analyze and predict the degra- dation degree of pesticide residues of the same crop at different time periods of bagging treatment, with the aim to provide some theoretical guidances for solving practical problems in real life.

Residual Levels and New Inputs of Chlorinated POPs in Agricultural Soils from Taihu Lake Region

Selected persistent organochlorine pesticides (OCPs), including 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its principal metabolites 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and 1,1-dichloro-2,2-bis(p-chlorophenyl)e- thane (DDD), hexachlorocyclohexane (HCH) and its isomers (α-,β-, γ-, and δ-HCH), hexachlorobenzene (HCB), endo- sulfan, dieldrin, and endrin were quantified to determine current levels of organochlorine pesticides, to assess the eco- toxicological potential, and to distin…

Residual Characteristics of Organochlorine Pesticides in Lou Soils with Different Fertilization Modes

Soll samples with three fertilization treatments （no fertilizer, corn straw and farm manure） collected from a Lou soil （Eum-orthic Anthrosol classfied using Chinese Soil Taxonomy） in northwestern China were analysed for residual levels and their characteristics of organochlorine pesticides （α-HCH, β-HCH,γ-HCH, δ-HCH, HCB, o, p＇-DDT, p, p＇-DDT, o, p＇- DDE, p,p＇-DDE, p,p＇-DDD, α-endosulfan, dieldrin and endrin）. Organochlorine pesticides （OCPs） were detected in all soil samples except δ-HCH and their total concentrations ranged from 159.31 ± 9.00 to 179.77 ± 2.58 ng g^-1 with an order of HCHs 〉 DDTs 〉 （dieldrin ＋ endrin） 〉 HCB 〉 α-endosulfan. Among all the compounds, γ-HCH had the highest concentration followed by p, p＇-DDE. The residual levels of HCH isomers and DDT as well as their metabolites in soil with different fertilization treatments were in the order of γ-HCH 〉β-HCH ≈ α-HCH 〉 δ-HCH and p,p’-DDE 〉 p, p’-DDT 〉 o,p＇-DDT 〉 p, p＇-DDD ≈ o, p＇-DDE, respectively. DDE/DDT ratios ranged from 1.59 ± 0.13 to 3.35± 0.16 and endrin/dieldrin ratios from 1.40 ±0.06 to 9.20± 4.05, both indicating no new occurrence of these pesticides in these soils, while α-HCH/γ-HCH ratios of 0.04 indicated a new input of lindane （almost pure γ-HCH） in the past several years. The farm manure treatments showed lower DDT residues than samples without fertilizer. Also addition of corn straw and farm manure increased soil organic matter content and decreased the soil pH which could retard the degradation of DDT in the soil.

Laboratory simulated dissipation of metsulfuron methyl and chlorimuron ethyl in soils and their residual fate in rice, wheat and soybean at harvest

Two sulfonylurea herbicides, metsulfuron methyl （Ally 20 WP） and chlorimuron ethyl （Classic 25 WP） were evaluated for their dissipation bchaviour in alluvial, coastal saline and laterite soils under laboratory incubated condition at 60% water holding capacity of soils and 30 ℃ temperature was maintained. In field study herbicides were applied twice for the control of grasses, annual and perennials broad leaves weeds and sedges in rice, wheat and soybean to find out the residual fate of both the herbicides on different matrices of respective crops after harvest. Extraction and clean up methodologies for the herbicides were standardized and subsequently analyzed by HPLC. The study revealed that the half-lives of metsulfuron methyl and chlorimuron ethyl ranged from 10.75 to 13.94 d irrespective of soils and doses applied. Field trials with rice, wheat and soybean also revealed that these two herbicides could safely be recommended for application as no residues were detected in the harvest samples.

Simultaneous Determination of 8 Pesticide Residues in Green Tea Based on Gas Chromatography-mass Spectrometry

To improve pesticide residues detection efficiency in tea, simultaneous de- termination of eight pesticide residues in green tea was developed based on gas chromatography-mass spectrometry （GC-MS）. The results showed that, - detected by the GC-MS under following conditions： acetonitrile as extraction and elution solvent, activated carbon and PSA tandem column as the stationary phase, elution volume of 12 ml the relationship between peak area and concentration of each residue （ametryn in the range of 0-100 pg/L, napropamide in the range of 0-10 000 gg/L, other pesticides in the range of 0-1 000 tJg/L） were linearly related, and their corre- lation coefficients were all greater than 0.999. The recovery rate the pesticides added to tea sample at legal concentration limits ranged from 73.6% to 116.8%, and the relative standard deviation from 1.47% to 15.58%. The new method we de- veloped is sensitive, specific and anti-interference, and thus provides test basis for the development of pesticide matrix reference materials in tea.

Organophosphorus Pesticide Extraction and Cleanup from Soils and Measurement Using GC-NPD

The objectives of this study were to optimize instrumental parameters and conditions for analysis of selected organop- hosphorus pesticides (OPPs) by gas chromatography (GC) with nitrogen-phosphorus detection (NPD) (GC-NPD); to select an appropriate solvent system; to conduct a comparison of sonication and shaking extractions; and to select an appropriate procedure for extracting organophosphorus pesticides from soils. Procedure I consisted of n-hexane or petroleum ether together with acetone used as solvents, while Procedure contained several solvents including acetone, methanol, dichloromethane, and n-hexane or petroleum ether. Experimental results indicated that a mixture of petroleum ether/acetone (2:1, v/v) could be used in place of n-hexane/acetone (2:1, v/v) as it was a less expensive solvent system. In addition, shaking under a water bath at 20 °C was more effective than sonication. Also, Procedure I was more effective, safer, and more timesaving than Procedure Procedure I was applied to three soil types of different organic matter content, with recoveries of the OPPs from the yellow-brown soils, which had a higher organic matter content, being lower than those from the yellow and red soils.

Pesticide Residues and Government Regulation in China─Evidence from Pesticide Residues in Fruits and Vegetables

China is a big producer and exporter of fruits and vegetables,and pesticide residues are an important factor affecting the quality and safety of fruits and vegetables and their export trade.In this paper,we analyzed the pesticide residue data on fruits and vegetables in 32 major Chinese cities between 2012—2019,the export data of Chinese fruits and vegetables and the role of pesticides in foodborne diseases.The results showed that pesticide residues in fruits and vegetables(PRFV)partial excess of maximum residue standard(MRL)and residues of banned pesticide were still widespread in China.By comparing the standards of pesticide residues in the European Union and China and addressing the agricultural situation in China,this paper analyzed the main causes of PRFV in China and put forward some policy suggestions for strengthening government regulation of pesticide application in agricultural products.

Statistical Analysis of Regularity of Pesticide Residues in Vegetables Produced in Inner Mongoli

[Objective]The paper was to study regularity of pesticide residues in vegetables produced in Inner Mongolia.[Method]Mathematical statistic analysis was carried out on 6 800 samples of veggies,fruits,leguminous vegetables,nuts and seeds produced in Inner Mongolia.[Result]The dominated vegetables in Inner Mongolia were green leafy vegetables,solanaceous vegetables and melon vegetables,and their yields accounted for 70%of the total vegetables production.Since 2003,with the rapid increase of detected vegetable numbers,the status of vegetable quality safety had entered into a new stage of sustainable steady after a rapid decline or periodic fluctuation,and the differences in safety levels were obvious,of which the range of exceeding standard rate of pesticide residues in solanaceous vegetables,melon vegetables and leguminous vegetables(about 55%of the total vegetables)was under 2%,with average values of 1.1%,1.6%and 3.1%,respectively.They belonged to stable type.The exceeding standard rate of pesticide residues in green leafy vegetables and Chinese cabbage group(about 30%of total vegetables)presented a decreasing trend year by year,wondering in the range of 7%-10%.They belonged to main risk type.The time period of exceeding standard of pesticide residues in root vegetables and cole vegetables was under predictable,and its exceeding standard rate in some years was over 5%(amplitude variation is over 15percentage points).They belonged to random risk type.The kinds of pesticides,which exceeding standard rate in vegetables were relatively intensive,presented variance in different vegetable species.70%of the pesticides belonged to intermittent over-limits and the probability was below 5%.About 20%tradition pesticides often exceeded standard and their probabilities were over 30%.The exceeding standard of organophosphorus and carbamates pesticides in vegetables presented a decreasing tend,while the risk of some new pesticides containing nitrogen element and high effective pyrethroids showed an increasing tendency.[Conclusion]The paper provided decision making services for agricultural management departments.

Capillary gas chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco

Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described.The determination was carried out by capillary gas chromatography(GC) with electron capture detection(ECD) and confirmed by GC-MS.The mean recoveries and relative standard deviation(RSD) were 93.2%～112.9% and 3.5%～6.7%,respectively at levels ranging from 0.01 to 0.1 mg/kg.The limit of determination was 0.001 mg/kg.Tobacco samples in routine check were successfully analyzed using the proposed method.

Evaluation of Pesticide Residues in Mango by a Multi-residue Analysis and GC/MS Triple Quadrupole

Mango fruit has a great national and international market, and Brazilian production is 1,900 thousand tons/year exporting to North America and Europe. However, the loss could occur during the production when it is affected by pests and climate conditions, so the increased use of chemical substances and their presence should be monitored. A task for governmental agencies, producers and food sales, attending the sanitary barriers requirements, is to distribute food free from contaminants, so laboratories involved in this type of work usually employ multi-residues analysis. The objective of this study was to evaluate the presence of pesticide residues in mango using QuEChERS method and mass spectrometry technique. Positive samples were compared with Brazilian maximum residues level （MRL） and the health risk exposure was evaluated using the acute dietary intake （ADI） parameter. A total of 20 samples were collected from January to March, in Sao Paulo city markets. The recoveries were in the range of 70% to 120%, and standard deviation was below 20%. The category of pesticides not permitted for the crop were found in l0 samples; eight samples presented pesticides below MRL and two samples above MRL for the fungicide procloraz. The ADI values were below 20% of ADI for an adult and the worst case was dimethoate with 69% of ADI for children. The time spent in monitoring studies and the viability of method chosen must be considered by pesticide residues laboratories during routine analysis of food quality control.

IN VITRO STUDY ON CYTOTOXIC EFFECTS OF THE ORGANOPHO SPHOROUS PESTICIDE PROFENOFOS ON THE GILL CELL LINE, FG-9307, OF THE FLOUNDER (PARALICHTHYS OLIVACEUS)

The FG 9307 cell line derived from the gill of flounder Paralichthys olivaceus was used in the present study to determine the acute cytotoxic effects of the organophosphorous pesticide, profenofos. It was found that the cell growth rate was markedly reduced by profenofos at the concentrations of 2.5, 5 and 7.5 mg/L tested; and that the fine structures of the cells were also altered by profenofos, as evidenced by dilation of nuclear membranes and mitochondria cristae, and presence of enlarged lysosomes with engulfed organelles and numerous vacuoles in the cytoplasm. Probably, mitochondria, the cell energy generating sites, are the most prominent sites of profenofos cytotoxity in the cells. This seems to be the first report of the use of marine fish cell line for evaluation of the acute in vitro cytotoxicity of organophosphorus pesticide.

Effects of Different Sowing Dates on Weed Suppression and Pesticide Residue in Soil

[Objective] To effectively suppress weeds and degrade pesticide residues in soil, pollution-free agricultural production is a very important way. [Method] In regions where high residual pesticides had been applied for a long term, 2-3 consecutive years of shallow ploughing after the autumn harvest, early shallow ploughing and sowing later in the next spring, and late ploughing and sowing were conducted,and the effects of the three measures on weed suppression and reduction of pesticide residue in soil were analyzed by measuring the length and fresh weight of crop radicles. [Result] Trifluralin applied in the A. membranaceus field for a long term limited the growth of the alfalfa seedlings. That is, the radicle length of each plant was 2.1-2.9 cm shorter than that of the control, and the fresh weight of each plant reduced by 0.19-0.20 g. Metsulfuron methyl applied in the alfalfa field for a long term also limited the growth of the alfalfa seedlings, that is, the radicle length of each plant was 1.9-2.0 cm shorter than that of the control, and the fresh weight of each plant reduced by 0.13-0.15 g. Shallow ploughing was conducted within two days after the autumn harvest, and all weed seeds on the ground were plowed into the plough layer 0-10 cm instead of deep soil. Early shallow ploughing in the next spring could make most seeds of weeds in surface soil sprout early, and sowing was conducted after 10 d, so that about 40% of weeds sprouting early were killed off. However, after shallow ploughing and sowing were conducted 10 d later than the normal sowing period, and around 30% of weeds were killed off. In addition,the weeds left in soil should be removed manually at the seedling stage or in late period. These measures had no adverse impact on the growth and development of crop radicles and yield. [Conclusion] In regions where pesticides with long-term residue had been applied for a long term, 2-3 consecutive years of shallow ploughing after the autumn harvest, different farming and sowing measures and artificia weeding could suppress weeds in the crop fields effectively, did not pollute soil environment, and promoted the degradation of pesticides left in soil.