苯醚甲环唑在套袋与不套袋苹果中的残留及消解动态

通过两年田间试验并结合气相色谱-电子捕获检测(GC-ECD)技术,研究比较了苹果套袋 和不套袋2种不同栽培方式下苯醚甲环唑在苹果中的残留及消解动态。结果表明:2011和2012年, 苯醚甲环唑在未套袋苹果中的原始沉积量分别为0.44和0.17 mg/kg,消解半衰期分别为12.8和15.5 d;2012年其在套袋苹果中的原始沉积量为0.056 mg/kg,半衰期为31.9 d。两年的试验表明,于苹果收获前35~42 d,按照10%苯醚甲环唑水分散粒剂的推荐剂量和1.5倍推荐剂量(有效成分分别为66.7和100 mg/L)施药2次和3次, 距末次施药后7 d采收,套袋和不套袋果实中苯醚甲环唑的残留量均低于我国最大残留限量(MRL)值0.5 mg/kg,其中套袋处理均低于0.03 mg/kg,表明苯醚甲环唑按照推荐剂量及次数施用是安全的;在套袋方式下,苯醚甲环唑残留量明显降低。     

Comparative purification methods for determination of triadimenol residues in plant material

Two procedures are described for the determination of residues of triadimenol and compared on cereal material. After extraction, purification is carried out by Florisil column chromatography in method I and by semi-preparative High-Performance Liquid Chromatography in method II. Triadimenol residues are quantified by gas chromatography with a thermoionic detector. With method I, interference was observed but not with method II. This specific procedure has been tested on other plant materials. Recoveries in the range of 90–98% indicate that this procedure is suitable for residue analysis of this fungicide with detection limits of 0·008 mg kg^?1 in wheat grains, 0·03 mg kg^?1 in wheat straw and 0·004–0·008 mg kg^?1 in other plants. Maximum residue limits in France are: 0·1 mg kg^?1 in grain, 2·0 mg kg^?1 in straw and 1·0 mg kg^?1 in other vegetables and fruit.     

苹果内吸磷残留量的动态酶化学研究

用Hestrin胆硷酯酶活性测定法,系統研究以不同方式施用内吸磷(E-1059)后,苹果内吸磷残留量的动态变化情况。施药方式有三种:(1) 浸果—仅对树上的苹果进行药浸,树叶和树枝不接触药液。(2) 噴叶—苹果以塑料膜包好后向树上嘖药,只树叶和枝上着药,而苹果不着药。(3) 浸枝——将带有果和叶的一段树枝剪下,断端浸入药液中迫使吸收药液24小时。检测結果:浸果施药后第一天内,苹果可检测出很高的内吸磷残留量(可达2 ppm左右),1天后残留量降到0.75 ppm以下,两周后残留量可降低到接近零;噴叶施药后12天内,經数次检测,均未发现有内吸磷残留;用药液浸枝,虽然第一天树枝吸收了不少的药液,但苹果中几乎检測不出内吸磷的残留,第二天换以水浸枝,却反而检测出内吸磷残留量(将及0.5 ppm),大約10天左右残留量降到接近零。試驗結果说明:一般噴雾时内吸磷的残留主要是由于药液直接接触苹果果皮所致,通过叶和枝内吸輸导至苹果上的药液是微乎其微的;浸果施药后第一天内残留量最高,以后逐漸降低,約两周后降到接近于零;浸枝时迫使吸入药液,但輸导至苹果上的药物甚少,并且内吸輸导需要一定时間,所以第二天残留量最高。关于苹果施用内吸磷的期限,似乎可职适当后延至收获前3或4周。     

三甲基硅重氮甲烷衍生化-气相色谱法测定水果蔬菜中乙烯利的残留

针对水果蔬菜中乙烯利的残留,建立了三甲基硅重氮甲烷衍生化-气相色谱的分析方法。样品用 V (甲醇) : V (盐酸) = 9:1的溶液提取,无水乙醚萃取,三甲基硅重氮甲烷衍生化15 min,采用气相色谱-质谱法定性,气相色谱仪-火焰光度检测器 (GC-FPD) 检测,外标法定量。结果显示:在0.01~2 mg/L范围内,乙烯利的质量浓度与其对应的峰面积间线性关系良好,相关系数大于0.999 6;此方法检出限为0.01 mg/kg,定量限为0.03 mg/kg;在辣椒、番茄、香蕉、苹果和梨的空白果蔬样品中分别添加0.01、0.1和1 mg/kg 3 个水平下,回收率为93%~102%,相对标准偏差为4.2%~7.3%。该方法准确度和灵敏度高,抗干扰能力强,能准确并快速测定出水果、蔬菜中乙烯利的残留量。     

Pesticide residues in food--acute dietary exposure

Consumer risk assessment is a crucial step in the regulatory approval of pesticide use on food crops. Recently, an additional hurdle has been added to the formal consumer risk assessment process with the introduction of short-term intake or exposure assessment and a comparable short-term toxicity reference, the acute reference dose. Exposure to residues during one meal or over one day is important for short-term or acute intake. Exposure in the short term can be substantially higher than average because the consumption of a food on a single occasion can be very large compared with typical long-term or mean consumption and the food may have a much larger residue than average. Furthermore, the residue level in a single unit of a fruit or vegetable may be higher by a factor (defined as the variability factor, which we have shown to be typically x3 for the 97.5th percentile unit) than the average residue in the lot. Available marketplace data and supervised residue trial data are examined in an investigation of the variability of residues in units of fruit and vegetables. A method is described for estimating the 97.5th percentile value from sets of unit residue data. Variability appears to be generally independent of the pesticide, the crop, crop unit size and the residue level. The deposition of pesticide on the individual unit during application is probably the most significant factor. The diets used in the calculations ideally come from individual and household surveys with enough consumers of each specific food to determine large portion sizes. The diets should distinguish the different forms of a food consumed, eg canned, frozen or fresh, because the residue levels associated with the different forms may be quite different. Dietary intakes may be calculated by a deterministic method or a probabilistic method. In the deterministic method the intake is estimated with the assumptions of large portion consumption of a 'high residue' food (high residue in the sense that the pesticide was used at the highest recommended label rate, the crop was harvested at the smallest interval after treatment and the residue in the edible portion was the highest found in any of the supervised trials in line with these use conditions). The deterministic calculation also includes a variability factor for those foods consumed as units (eg apples, carrots) to allow for the elevated residue in some single units which may not be seen in composited samples. In the probabilistic method the distribution of dietary consumption and the distribution of possible residues are combined in repeated probabilistic calculations to yield a distribution of possible residue intakes. Additional information such as percentage commodity treated and combination of residues from multiple commodities may be incorporated into probabilistic calculations. The IUPAC Advisory Committee on Crop Protection Chemistry has made 11 recommendations relating to acute dietary exposure.     

臭氧去除果蔬中农药残留研究进展

水果、蔬菜中农药残留的清洗去除研究是进一步提升食品安全的保证。臭氧处理技术是去除农药残留的常用方法之一。本文主要介绍了用于去除水果蔬菜上农药残留的臭氧处理技术,包括:臭氧产生方式、应用形式以及臭氧与其他方法联合处理技术的应用,综述了影响农药残留去除效果的因素,也介绍了臭氧去除农药残留的同时对果蔬外观、营养等影响,进一步探究了臭氧去除农药残留的作用机制和应用价值,旨在为臭氧清洗技术用于去除果蔬农药残留的研究提供理论和应用参考。     

Persistence of benfluralin in soil and its uptake by carrots

Analytical methods are described for the determination of residues of benfluralin in soil and carrots. All plots treated with 1.3 or 1.9 kg benfluralin/ha produced average carrot yields significantly higher than untreated plots. Degradation of benfluralin in soil was very slow during the winter. As the temperature rose, the rate of benfluralin decline was accelerated; 324 days after incorporation, benfluralin residues were reduced to about 11 and 14% of the applied dose. The average total residues of benfluralin found in whole carrots were 210 ± 18 and 240 ± 47 ng/g following doses of 1.3 and 1.9 kg a.i./ha respectively. The peel of carrots contained 92% of the total residue, and there seemed to be little translocation of the compound through the plant tissues.     

An investigation of the non-solvent-extractable residues of [14C]chlorpyrifos-methyl in stored wheat

The residues of [¹⁴C] chlorpyrifos-methyl remaining in wheat after solvent extraction accounted for 28% of the applied dose after an extended period of storage. A bioassay of these residues was carried out using Tribolium castaneum and a significant reduction in the numbers of adults reaching maturity was observed. Attempts to release the non-solvent-extractable residues using an enzymic digestion procedure were unsuccessful, as were several of the chemical solubilisation procedures investigated. A water/methanol extraction system was successful in releasing up to 86% of the radioactivity leaving 10% still non-extractable. Analysis of this solubilised residue revealed that 59% was present as the pyridinol metabolite of chlorpyrifos-methyl and 26% was a polar material composed of two main components. Bioassay tests of these metabolites revealed that the reduction in the number of insects reaching maturity could be associated with the pyridinol metabolite.     

果蔬中农药残留检测技术研究进展

对目前水果、蔬菜中农药残留分析检测方法及其前处理过程以及快速检测技术作了综述。固相萃取（SPE）、超临界流体萃取（SFE）等新的萃取方法已逐渐代替了液-液萃取（LLE）等传统提取方法。色谱技术是农药残留分析中的重要手段。气相色谱（GC）、高效液相色谱（HPLC）及其联用技术是现阶段农药残留分析中的主要检测方法。指出了今后该领域的研究方向。     

MSPO在农药残留分析中的应用进展

基质固相分散是近年来研发的检测蔬菜、水果中农药残留的提取和净化前处理技术,净化过程无需预淋洗、淋洗、洗脱等繁杂步骤.本文简要介绍了基质固相分散法的原理及影响因素并结合当前MSPD技术的最新进展,介绍了MSPD技术在农药残留分析时样品前处理上的应用实例.最后指出了应用中存在的问题以及发展趋势.     

Persistence,metabolism and safety evaluation of thiamethoxam in tomato crop

BACKGROUND: Thiamethoxam, a neonicotinoid insecticide, has been widely accepted for use in various crops, including vegetables, owing to its high efficacy against various chewing and sucking insect pests. In this particular study, the authors examined the residue dynamics of this insecticide in tomato and soil and calculated a safety index for this insecticide in an Indian context. RESULTS: In tomato fruits, the insecticide dissipated from 82 to 87% in 10 days with a half‐life of 4 days, whereas dissipation in soil, under tomato crop, varied between 72 and 75% in 15 days with a half‐life of 9 days. Total residues reached below detectable level in 15 days in tomato fruits and 20 days in soil. Maximum damage (30%) was found in control plots, as opposed to 8–10% of fruit damage in treated plots. One degradation product was detected on the tomato fruit surface, and three metabolites were identified in tomato fruits by the LC‐MS technique. The metabolites have been reported for the first time in tomato fruits. CONCLUSION: Thiamethoxam at normal and double the recommended use rate effectively controlled aphids, whiteflies and Helicoverpa, as the insect population decreased to a minimum within 10 days of spraying in comparison with the control. There was no significant difference between the two rates of application, and both thiamethoxam treatments significantly increased tomato fruit yield compared with the untreated control. A maximum residue limit (MRL) of 0.05 mg kg^?1 for tomato has been proposed, with a corresponding preharvest interval (PHI) of 8 days. These parallel advances in toxicology and analytical chemistry have strengthened the observations that thiamethoxam can be used safely and efficiently in crop protection programmes. Copyright © 2009 Society of Chemical Industry     

Fonofos residues in an organic soil and vegetable crops following treatment of the soil with the insecticide

Fonofos (O-ethyl S-phenyl ethylphosphonodithioate) was applied to an organic soil as band treatment at the rates of 1.12 and 2.24 kg/ha. The persistence of the insecticide and its translocation into onions and two rotation crops (lettuces and carrots) was studied under field conditions. Proportionally more residues persisted in the soil from the higher rate of application. In autumn, 4 months after soil treatment, about 40-48 % of the initially recovered levels of fonofos remained in soil. However, the amount of fonofos present at the harvest time, during the second growing season was only 16–26% of the insecticide concentration found in spring. Onions harvested 4 months after application of fonofos had no detectable residue (> 0.005 mg/kg) whereas lettuces and carrots grown in the following year contained fonofos in various amounts. At the lower rate of application the insecticide residues in lettuces and carrots were < 0.005 and 0.025 mg/kg, respectively, and those from the higher application rate were 0.012 and 0.036 mg/kg. About 72–80% of the residue could be removed by peeling the carrots. No residue of the oxygen analogue, O-ethyl S-phenyl ethylphos-phonothioate (I) was detected in any soil or crop samples.     

Mercury content of some foodstuffs of vegetable origin

An analytical method and results are given for the determination of total mercury residues in: Brussels sprouts; cabbages, heading broccoli and kale; potatoes; apples; carrots; imported tomatoes; tinned tomatoes, tomato juices and purees; rice; sugar. Residues in the 146 samples were in the range <0.001 to 0.010 parts/million, the mean being 0.0027 parts/million.     

铜制剂农药对生态环境影响研究

阐述了因长期施用波尔多液致使铜在果园土壤中的残留积累状况及其对果 园作物生长的影响。对几种新的铜制剂农药在果树和蔬菜上的残留进行了试验，并对其在今 后使用中铜在土壤中的积累规律及允许安全使用年限作了预测。     

哒螨灵在苹果上的残留量检测与消解动态

研究了哒螨灵在苹果上的残留分析方法及其在苹果中的消解动态和最终残留量。哒螨灵经乙酸乙酯-丙酮(1∶ 1,体积比)提取后,用弗罗里硅土净化、浓缩、定容,用带ECD检测器的气相色谱仪测定。哒螨灵的最小检出量为1.0×10-11 g ,最低检出浓度为0.02 mg/kg,回收率在83.6% ~104.1%之间,变异系数为3.0% ~4.3%。2006年在山东两地的田间残留试验结果表明,哒螨灵在莱州和五莲苹果中的消解半衰期分别为4.1和3.8 d,最终残留量分别为0.059和0.040 mg/kg。     

两种蔬菜中甲胺磷、氧乐果和克百威的残留量分析

分别选取一种瓜菜 (黄瓜 )和一种叶菜 (生菜 ) ,选择了两种有机磷 (甲胺磷、氧乐果 )和一种氨基甲酸酯类 (克百威 )农药 ,对这 3种农药在两种蔬菜中的残留测定方法进行了研究。采用弗罗里硅土柱提取的方法进行前处理 ,淋洗液浓缩后用 GC- NPD测定 ,建立了一种简便快速的检测方法 ,并采用该方法对实际处理样本进行了测定。从方法添加回收率和实测数据可以看出 ,该方法净化提取效果好 ,结果平行性好 ,灵敏度较高 ,是一次快速准确测定蔬菜中农药残留的成功尝试。     

Residues in apples and sweet cherries after methyl bromide fumigation

Methyl bromide fumigations are used to treat apples, Malus domestica Borkh, and sweet cherries, Prunus avium (L), before export to Japan. In order to expand existing markets, additional cultivars are being prepared for export to Japan. As part of the approval process, residue analyses must be conducted and residues must be at acceptable levels. Five apple cultivars (‘Braeburn,’ ‘Fuji,’ ‘Gala,’ ‘Jonagold,’ and ‘Granny Smith’) were fumigated at 40 g m⁻³ for 2 h at 10 °C, and six sweet cherry cultivars (‘Brooks,’ ‘Garnet,’ ‘Lapin,’ ‘Rainier,’ ‘Sweetheart,’ and ‘Tulare’) were fumigated for 2 h with 64 g m⁻³ at 6 °C, 48 g m⁻³ at 12 °C, 40 g m⁻³ at 17 °C, and 32 g m⁻³ at 22 °C. Three replicates of fruit from each fumigation were analyzed for methyl bromide and bromide ion residues periodically with time. Methyl bromide residues for both apples and cherries were the highest immediately after fumigation, but rapidly declined so that only ‘Braeburn’ had residues >8 µg kg⁻¹ after 13 days and, except for ‘Lapin,’ all cherries were <1 µg kg⁻¹ after seven days. Average bromide ion residues were between 3.3 and 4.9 mg kg⁻¹ among apple cultivars, and between 3.7 and 8.0 µg kg⁻¹ among cherry cultivars. Published in 2000 for SCI by John Wiley & Sons, Ltd     

Multiresidue method for captan,folpet, captafol,vinclozolin and iprodione on italian apples and pears by capillary gas–liquid chromatography with electron-capture detection

A method is described for the simultaneous determination of residues of five fungicides used for foliar treatment of apple and pear trees, and for postharvest application. After extraction, the mixture of these fungicides is cleaned-up on a ‘SEP PAK C₁₈’ cartridge and the components determined by gas-liquid chromatography with electron-capture detection. The minimum detectable amounts in apples and pears, on a fresh weight basis, were 0.005mg kg⁻¹ for vinclozolin, 0.010mg kg⁻¹ for captan, folpet and iprodione, and 0.020 mg kg⁻¹ for captafol. The percentage recovery for each fungicide (calculated by analysing four samples of untreated apples and pears, to which varying concentrations of each active ingredient had been added) varied for vinclozolin between 70.0 and 89.2, for captan between 72.0 and 83.8, for folpet between 73.0 and 93.0, for captafol between 70.8 and 91.8, and for iprodione between 75.1 and 97.1.     

Effect of different formulations on tebuconazole residues in stone fruits

BACKGROUND: The correlation between pesticide residue levels and formulation of an active substance is often not considered, even if it is reasonable to expect some differences arising from behaviour during dilution and spraying, from adhesion to plant and from degradation. An experimental study to investigate the magnitude of tebuconazole residues as a function of different tebuconazole formulated products was carried out in Italy. The fungicide was applied as wettable powder (WP) and water‐dispersible granule (WG) formulations to peach, plum, apricot and nectarine orchards, on four different sites. The fruit samples gained from the field trials were quantitatively analysed by gas chromatography with a nitrogen phosphorus detector (GC/NPD) for tebuconazole residues. RESULTS: Tebuconazole residues in the fruits gained from the plot treated with the WP formulation, 14 days after application, were in the range 0.01–0.07 mg kg^?1, while corresponding residues in the plot treated with the WG formulation were in the range 0.01–0.06 mg kg^?1. CONCLUSION: No significant differences in the residue levels of tebuconazole could be observed between the trials conducted with the WP and the WG formulation. Copyright © 2009 Society of Chemical Industry     

Development of methods for the analysis of crops and soils for residues of benzoylprop-ethyl and its breakdown products

Methods are described for the analysis of residues of the herbicide benzoylpropethyl, ethyl (±)-2-[ N-(3,4-dichlorophenyl)benzamido]propionate, and its breakdown product, (±)-2-[ N-(3,4-dichlorophenyl)benzamido]propionic acid, in wheat and soil. In wheat the acid degradation product conjugates with plant sugars and the present paper includes methods for determination of these residues either separately or as a combined residue with unconjugated acid. Efficient extraction procedures have been developed together with partition and column chromatographic techniques for purification of extracts. The full analytical procedures are described and the final determinations are by g.1.c. with electron capture detection with blank values for field samples in the range 0.01–0.05 mg/kg. Good recoveries were obtained. Radiochemical techniques have been used to verify the extraction and subsequent procedures in the methods.