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1.
《土壤通报》2015,(6):1415-1419
研究建立了土壤中甲氰菊酯、三氟氯氰菊酯、顺式氯菊酯、反式氯菊酯、氯氰菊酯、氟氰戊菊酯、氰戊菊酯和溴氰菊酯8种拟除虫菊酯类农药残留的超声提取-硅胶柱净化-气相色谱(GC)检测方法。以石油醚/丙酮(v/v,2:1)溶液为有机提取剂,超声提取土壤样品,旋转蒸发仪浓缩,经自制硅胶柱以10 ml石油醚/乙酸乙酯(v/v,9:1)溶液进行分离净化并浓缩后用正己烷定容,样品采用气相色谱法FID检测器检测。研究结果表明,该方法对土壤样品中8种拟除虫菊酯的加标回收率较高,平均值在84.9%~101.3%之间。通过实验优化了8种拟除虫菊酯类化合物的分离和测定条件。该提取和检测方法具有简便、快捷、成本低、净化效果和重现性好等特点,适合于土壤中痕量拟除虫菊酯类农药残留的测定。 相似文献
2.
<正> 在加拿大广泛使用拟除虫菊酯来控制蔬菜害虫,但需要提供这类农药在作物上的残留数据,才能获得登记。本文报道了防治园葱、莴苣、芹菜、菜豆和草莓上害虫的几种拟除虫菊酯农药的田间试验结果。试验于1931年、1982年在安大略进行。用悬挂式喷雾器施药,用药量为0.07—0.08公斤有效成分/公顷,使用2—3次,每次间隔7天,每处理设4个重复。采集成熟果实或食用部分洪农药残留分析。样品于5℃下冷藏,从采样到分析不超过72小时,用带电子捕获器气相色谱仪测定残留量,5种 相似文献
3.
从农药厂废水中分离到能够降解多种拟除虫菊酯的复合菌群JZ-1,对该菌群降解特性研究结果表明,最佳降解条件为pH7、温度30℃;在最佳条件下培养15d,对100mg·L-1甲氰菊酯、氟氯氰菊酯、氯氰菊酯的降解率分别为53.27%、33.36%、41.39%。对该菌群的16S rDNA进行扩增和RFLP及测序分析结果表明,该菌群含有丰富的细菌资源,该菌群的优势种群包括红假单胞菌属（Rhodopseudomonas）和紫单孢菌科细菌（Porphyromonadaceae bacterium）。该研究为拟除虫菊酯的降解菌资源的挖掘和利用提供了理论参考。 相似文献
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5.
拟除虫菊酯是一类高疏水性仿生杀虫剂,进入环境中易被颗粒物或油滴吸附,最终聚积在底泥沉积物中;同时它可以随水流或胶体等途径发生迁移,已被研究证实在使用及未使用拟除虫菊酯地区的河流、湖泊底泥中均检测到其残留。本文介绍了底泥中拟除虫菊酯的来源、归趋、生物效应,重点分析了拟除虫菊酯的吸附/解吸、降解作用及湿地生态系统对其归趋的影响;讨论了拟除虫菊酯的水生生物毒性、生物富集作用等生物效应,评述了其疏水性及生物可利用性对其毒性的影响,可为拟除虫菊酯水生生态系统风险评价等研究提供重要参考信息。 相似文献
6.
采用MECC在线堆积同步检测茶叶中七种残留农药 总被引：4，自引：0，他引：4
为解决茶叶中的痕量农药残留的快速检测问题,建立了一种基于胶束毛细管电泳在线堆积技术的茶叶中7种拟除虫菊酯类农药痕量残留的一次进样同步检测方法.通过参数优化,得到最优的柱上在线堆积浓缩操作工艺:以15%异丙醇、20%乙腈、60 mmol/L十二烷基硫酸钠(SDS)和50 mmol/L tris的混合物为背景缓冲溶液(BGS).茶叶的浸提液经过固相萃取净化吹干后,用1 mmol.L SDS溶解溶液残渣.进样100 s后施加反向电压,进行农药反向在线堆积,当电流恢复至正常分离时的95%时改变电压方向,进行正常分离.经过在线堆积浓缩,7种拟除虫菊酯类农药痕量残留堆积因子均高于17,回收率在82%以上,检测下限分别达到:功夫菊酯0.05 mg/kg、联苯菊酯0.05 mg/kg、百树菊酯0.05 mg/kg、高效氯氰菊酯0.05 mg/kg、溴氰菊酯0.2 mg/kg、二氯菊酯0.05 mg/kg、氰戊菊酯0.05 mg/kg,满足了2006年欧盟茶叶中拟除虫菊酯类农药残留的最低标准. 相似文献
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8.
通过对生产基地和销售市场蔬菜水果监测分析，虽然农产品质量安全日益提高，但农药残留超标问题依然存在，共检出多种有机磷农药（甲胺磷、氧化乐果、甲基对硫磷、对硫磷、甲拌磷、毒死蜱等）残留和多种拟除虫菊酯农药（三唑酮、氯氰菊酯、氰戊菊酯等）残留。农药残留超标情况由过去的单一高毒农药向多种农药残留超标方向发展，单一蔬菜样品中往往同时检出多种有机磷或有机氯农药。 相似文献
9.
为检测草莓基质中的农药残留,建立了固相萃取-毛细管柱气相色谱方法,可同时检测草莓果实中百菌清、毒死蜱、粉唑醇、腈菌唑、高效氯氰菊酯、氰戊菊酯和嘧菌酯7种农药的残留量。样品经乙腈提取,C18固相萃取柱净化,GC-ECD进行定性及定量分析。百菌清、毒死蜱在0.05～1.0μg.mL-1,粉唑醇、腈菌唑、高效氯氰菊酯、氰戊菊酯和嘧菌酯在0.5～10.0μg.mL-1浓度范围内呈现良好线性关系。方法平均回收率为85.3%～102.7%,RSD小于5%,检出限范围为0.005～0.132mg.kg-1。该方法简单、快速、灵敏、准确,能满足国标中相关农药残留限量测定的要求。 相似文献
10.
拟除虫菊酯类农药的色谱分析法 总被引：2，自引：0，他引：2
拟除虫菊酯类杀虫剂具有用量低，效果好，杀虫谱广，对温血动物毒性低等优点，目前广泛用于防治农业害虫。在拟除虫菊酯的研究和生产过程中，在环境影响农药残留调查时都要求提供准确快速的测定方法。但是由于拟除虫菊酯分子结构的特点，它们都包含多个光学异构体，这些异体栖往往又具有不同的生物活性，因此必须解决异构物的分析方法问题，本总结了近年来拟除虫菊酯的气相和液相色谱分析方法进展，并介绍了作自己的工作经验。 相似文献
11.
从化工厂污泥中分离到一株酵母菌 ,初步鉴定为德氏酵母属 (Debaryomycessp ) ,命名为Gb。该菌株可以在 0～ 2 0 %Na2 SO4环境中生长 ,并能以苯酚为唯一碳源和能源。其苯酚降解最适浓度为 1 0 0 0mgL-1 ,最适Na2 SO4浓度为 5 %,最适pH和温度分别为 5 5和 30℃ ,在 2 5 0ml三角瓶中最适装液量为 1 0 0ml。当Na2 SO4盐浓度为 5 %、苯酚浓度为 1 0 0 0mgL-1 时 ,最适条件下培养 3天即能降解 95 %的苯酚。本文还对其耐盐机理进行了初步研究 ,发现细胞内海藻糖含量随外界盐浓度增加而增加 ,表明Debaryomycessp 在高盐条件下能以海藻糖作为渗透调节物质。 相似文献
12.
Andrea Rodríguez Blanco Margarita Sicardi Lillian Frioni 《Biology and Fertility of Soils》2010,46(4):419-425
The aim of this work was to evaluate the competitive ability between Rhizobium leguminosarum bv trifolii strain U204 used as commercial inoculants in Uruguay for Trifolium repens L. and Trifolium pratense L. and two native strains isolated from inoculated pastures of T. pratense. T126 is an efficient nitrogen fixer and a melanin producer strain; T70 is inefficient and a melanin non-producer strain;
and U204 is very efficient in both hosts but is a melanin non-producer strain. Competitiveness between the strains was determined
in experiments in pots and in growth pouches under controlled conditions. In the last experiment, we evaluated pH of plant
nutrient solution and inoculum ratios. Plant dry weight was determined, and the identification of nodule bacteria was done
using melanin production and DNA fingerprinting (GTG5-PCR). The U204 symbiotic efficiency was not affected by the co-inoculation with the others two native strains. The T70 strain
was a poor competitor when was co-inoculated with one of the effective strains in both experiments. Our results confirmed
a “selective nodulation” because an effective symbiosis occurred preferentially over an ineffective one in Trifolium species. The native effective strain competed with U204 for nodule formation in both clovers species, but the nodule occupancy
depended on the inoculum ratio. The pH of nutritive solution did not affect competition ability of the studied strains. It
may be possible to isolate efficient, competitive, and genetically different native rhizobial strains to be used as inoculant
strains for clover pastures in Uruguay. Both (GTG)5-PCR and melanin production were useful methods to identify nodulating bacteria in competition studies. 相似文献
13.
Aftab Afzal Shahid Saleem Zafar Iqbal Gul Jan Muhammad Faisal Anwar Malik Saeed Ahmad Asad 《Journal of plant nutrition》2014,37(13):2144-2156
The effect of inoculation of Rhizobium or Pseudomonas, or both, in the presence and absence of phosphorus pentoxide (P2O5) fertilizer on wheat yield was tested. The experiment was conducted outdoors in potted soil during two consecutive years under natural conditions. Rhizobial strain (Thal 8-chickpea nodulating bacteria) and Pseudomonas strain (54RB), both indigenous P solubilizers were applied in broth culture at seedling stage. Fertilizer in the form of P2O5 was an additional treatment applied at sowing time. Results revealed that inoculation of Pseudomonas strain in presence of phosphorus (P) fertilizer increased yield up to 41.8% when it was compared with only P fertilizer applied. Co-inoculation of Rhizobium and Pseudomonas strains with the P2O5 treatment however resulted in increased grains yield by 10% over the P2O5 treatment alone. It is inferred that inoculation with Rhizobium and Pseudomonas combined with P2O5 is not only environmentally beneficial but also economically sound and productive, with wheat yield increases of 10% to 42%. 相似文献
14.
Nitrous oxide (N2O) release by Streptomyces nitrosporeus in a sandy loam soil as affected by pO2, pH and amount of easily decomposable organic carbon In model experiments under defined conditions (80%WHC, 300 μg nitrate-N g?1 dry soil, 30°C) the effect of pO2, pH and addition of easily decomposable organic matter on nitrous oxide production by Streptomyces nitrosporeus DSM 40023 from a sterilized sandy loam soil was studied. This streptomycete reduces nitrate to N2O but not to N2. The strain was inoculated into a sterilized sandy loam soil (pH 6), enriched with nitrate and incubated at approximately 20 and 10% (v/v) O2 for 26 days. In another series of experiments the pH was increased with NaOH-solution up to pH 7 or the soil was enriched with pulverized leaves (1%) to increase mineralization activity and the demand for electron acceptors. In the headspace the concentration of O2, CO2 and N2O was analysed by GC. The soil concentration of NO3?, NO2? and NH4+ was measured as well as the pH value. The population density was determined by the plate count method. At a decreased oxygen concentration of about 2.5% (v/v) in the headspace, S. nitrosporeus increased the release of N2O. In the experiments with an initial oxygen concentration of approximately 20% (v/v) this threshold of about 2.5% /(v/v) O2 was hardly reached and consequently only little N2O was produced. Apparently, S. nitrosporeus uses O2 in preference to nitrate, which is characteristical of nitrate respiration. A pH increase from pH 6 to 7 reduced the lag phase significantly and increased the rate of oxygen consumption, CO2 release and N2O production. Maximum nitrous oxide production was reached after 13 days. The result indicated that streptomycetes like S. nitrosporeus may use nitrate alternativly to O2 to maintain energy conservation (ATP synthesis) with the release of N2O. So far, nothing is known about the role of streptomycetes in contributing to N2O production in natural soils. 相似文献
15.
Summary This study compares N mineralization in soils treated with crop residues [corn (Zea mays L.), soybean (Glycine max (L.) Merr.), sorghum (Sorghum vulgare Pers.)] or alfalfa (Medicago sativa L.) at three adjusted soil pH values (4, 6, and 8); pH was adjusted with dilute H2SO4 or KOH. A sample of soil (20 g) was treated with 0.448 g plant material (equivalent to 50t ha–1), mixed with 20 g silica sand adjusted to the pH of the soil, and packed in a leaching tube. The soil-sand mixture was leached with 100 ml 5 mM CaCl2 adjusted to the same pH as that of the treated soil to remove the initial mineral N, and incubated at 30°C. The leaching procedure was repeated every 2 weeks for 20 weeks. Results from three soils showed that N mineralization increased as the soil pH increased. In one soil (Lester soil), significant amounts of NH
4
+
-N accumulated at pH 4 during the first 12 weeks. Treatment with corn and soybean residues resulted in a marked reduction in N mineralization, especially at pH 4. The percentage of organic N mineralized from sorghum residue and alfalfa added to soils increased as the soil pH increased; the values ranged from 7.7% to 37.0% for sorghum and from 17.2% to 30.1% for alfalfa. 相似文献
16.
M. Salvador-Figueroa V. M. Ruíz-Valdiviezo M. A. Rogel-Hernandez F. A. Gutiérrez-Miceli C. I. Rincón-Molina L. Dendoveen 《Journal of plant nutrition》2016,39(10):1449-1459
A diazotrophic bacterial strain denominated 11B isolated from the rhizosphere of a banana plant (Musa spp.) was characterized morphologically, biochemically, and phylogenetically, whereas the symbiotic potential of the strain was assessed through tests of host range, interstrain nodulation competitiveness, and capacity to synthesize indole-3-acetic acid (IAA) and solubilize phosphate. Based on morphological and physiological–biochemical properties, as well as 16S ribosomal deoxyribonucleic acid (rDNA) sequence and phylogenetic analysis, the strain 11B belonged to the genus Rhizobium with 100.0% sequence similarity with Rhizobium tropici CAF440. The optimum growth temperature and pH for strain 11B are 28°C and 7.2, respectively. This strain was able to produce IAA, solubilize phosphate, and fix large amounts of nitrogen (N2) and form effective nodules on the legumes Acaciella angustissima, Gliricidia sepium, Leucaena leucocephala, Lysiloma acapulcensis, and Phaseolus vulgaris. The rhizobial strain 11B was used successfully as a biofertilizer in agriculturally important legumes, forest trees, and agroindustrial plants. 相似文献
17.
NH3 volatilization from surface-applied urea, diammonium phosphate (DAP), and calcium ammonium nitrate (CAN) was measured with chambers through which air was drawn continuously. Two sandy soils and two sandy loam soils, which had been treated with and without time for the last 25 years, were used for the experiments. The accumulated NH3 loss from CAN applied to an unlimed sandy soil was linearly related to time. For the other treatments the accumulated loss was exponentially related to time. The NH3 loss was exponentially related to the maximum soil pH of the fertilizer-amended soil, and was inversely related to the content of exchangeable H+. Due to the low cation exchange capacity of these light-textured soils the NH3 loss was not reduced as the soil CEC increased. The maximum pH after soil amendment was related to soil pH. Therefore, a model is proposed that relates the NH3 loss solely to fertilizers and soil pH. The NH3 loss was less than 5% from CAN, about 20% from DAP, and about 30% from urea, with the insignificant loss from urea applied to the unlimed sandy soil excluded. The NH3 loss from surface-applied DAP was related to the air flow rate and a transfer coefficient (K
a) was estimated. K
a increased exponentially with the flow rate. At a flow rate above 3.9 liters min–1 (20 volume exchanges min–1) no further increase was seen. 相似文献
18.
Danute Karcauskiene Steponas Ciuberkis 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(8):688-697
ABSTRACTThe aim of the present study was to investigate changes of weed species density as a result of long-term (1976–2005) exposure to different soil pH levels, and P2O5:K2O amount in soil created by initial and subsequent periodical liming, and fertilization. As a result of liming during the period 1976–2005, average soil pH levels at the start of the sixth crop rotation (2001–2005) ranged from 4.1 (unlimed) to 6.6. And in each pH plot were four sub-plots with a different amount of mobile phosphorus:potassium. In acid soil (pH 4.1), in spring oilseed rape and in spring barley crops, the dominant weed Spergula arvensis density decreased significantly at a pH of 5.1 or higher. With increasing amount of P2O5:K2O in soil, the abundance of S. arvensis in spring rape and spring barley crops was reduced at all soil pH levels. At pH 5.1, Chenopodium album and Tripleurospermum perforatum were prominent. Elytrigia repens tended to decrease with increased alkalinity and nutrient amount in soil. With reduction of soil acidity from pH 4.1 to 6.6, the total weed infestation consistently declined in all crops. A low amount of P2O5:K2O in soil caused the decline in the abundance of S. arvensis, E. repens and increase in C. album and T. perforatum. 相似文献
19.
Tian Li Xin-Ping Deng Jin-Jun Wang Hui Zhao Lei Wang Kun Qian 《Water, air, and soil pollution》2012,223(6):3271-3279
A Gram-negative bacterium strain LWD09, capable of growing aerobically on 3,4-dichloroaniline (DCA) as the sole carbon and energy source, was isolated from the farm field. This bacterium was identified as Myroides odoratimimus strain by morphological, physiological, and biochemical characteristics as well as 16S rDNA sequence. Analysis of culture pH, temperature, cells growth, and DCA concentration demonstrated that strain LWD09 could effectively degrade DCA without a lag phase. The kinetics of DCA degradation was well described using the Andrews equation, and the kinetic parameters were as follows: q max?=?1.74?h?1, K s?=?43.5?mg?L?1, and K i?=?230.3?mg?L?1. In addition, strain LWD09 was found to be moderately halophilic and showed the highest power of DCA degradation in 5% NaCl (w/w, %). With initial concentrations of 30, 100, and 200?mg?L?1, 100%, 80.4%, and 33.2% of DCA were transformed after 96?h in 5% NaCl, respectively. These results suggest that strain LWD09 has the potential to degrade DCA in saline wastewater. To date, this is the first report on the degradation of DCA by a M. odoratimimus strain with moderate salinity tolerance. 相似文献
20.
《Communications in Soil Science and Plant Analysis》2012,43(17-18):2775-2786
Abstract The sorptive properties of zeolites (a natural zeolite and 3 synthetic zeolites) for cadmium (Cd) were investigated with the intention of selecting suitable materials, for use as amendments in contaminated soils, to reduce the uptake of Cd by field crops. The Cd sorption data were well described by the Langmuir and the Freundlich equations and the coefficients values indicated significant sorptive capacities for Cd by these minerals. Synthetic zeolites have 100 to 500 times greater sorption capacities than the natural zeolite. In all cases, sorption increased with increasing pH and this relationship was linear over the pH range between 3 and 10 for the natural zeolite whereas for the synthetic zeolites a sharp increase was observed between pH 3 and 6. The critical pH above which maximum Cd sorption occurred on synthetic zeolites coincided with the pH where mineral dissolution ceases. The natural zeolite showed an inverse relationship between particle size (<0.15–2.0 mm) and Cd sorption. In desorption experiments with natural zeolite, 10 sequential extractions with 0.01 MNaC104 removed 19% Cd from the lowest sorption treatment and 44% of the metal from the highest level, showing that Cd was bound more strongly with decreasing concentrations. Desorption was greater with 0.01 MKC104than 0.01 MNaC104 especially in the first 5 extractions. 相似文献