75％氯吡嘧磺隆水分散粒剂在玉米及土壤中的消解动态与残留

[目的]评价氯吡嘧磺隆在玉米上使用的安全性,建立其使用规范.[方法]于2009-2010年在南京和郑州两地进行了75％氯吡嘧磺隆水分散粒剂在玉米和土壤中的消解动态和最终残留试验.样品用丙酮提取,乙酸乙酯萃取净化后,用超高效液相色谱-电喷雾串联四极杆质谱检测,外标法定量.[结果]消解动态试验结果表明:在植株和土壤中半衰期分别为0.78～0.97、7.00～16.90 d.最终残留试验表明:75％氯吡嘧磺隆按推荐剂量(45 g a.i./hm2)和推荐剂量的1.5倍(67.5 g a.i./hm2)施药,玉米苗后3～5叶期施药1次,玉米收获期采样,检测的玉米籽粒、玉米植株及土壤中氯吡嘧磺隆的残留量均低于0.1 mg/kg.[结论]拟推荐我国氯吡嘧磺隆在玉米和玉米秸秆上的最大残留限量为0.1 mg/kg.     

水稻田除草剂四唑嘧磺隆的合成进展

四唑嘧磺隆为美国杜邦公司开发的磺酰脲类除草剂,是一种低毒、广谱、高选择性的除草剂。着重讨论了四唑嘧磺隆重要中间体的合成路线。     

磺酰脲类除草剂四唑嘧磺隆

磺酰脲类除草剂四唑嘧磺隆为美国杜邦公司开发的水田除草剂,azimsulfuron即为其通用名,四啥生为中文通用名,商品名为Azin,Gulliver、康宁。代号：DPX－A8947,JS－458。化学名称为：1－（4,6－二甲氧基嘧啶－2－基）－3－[1－甲基－4－（2－甲基－2H－四唑－5－基）吡唑－5－基磺酰基]脲。结构式如下。     

25%啶嘧磺隆水分散粒剂的反相高效液相色谱测定

叙述了采用反相高效液相色谱外标法,以甲醇-水作为流动相,用C18柱和紫外检测器(245nm),测定了25%啶嘧磺隆水分散粒剂的含量.结果表明:方法的标准偏差为0.072,变异系数为0.28%,平均回收率为99.86%,线性相关系数为0.9998.     

30%甲酰胺基嘧磺隆水分散粒剂高效液相色谱分析方法

采用高效液相色谱仪分析30%甲酰胺基嘧磺隆水分散粒剂的质量分数,使用C₁₈不锈钢反相色谱柱和紫外可变波长检测器,以甲醇+磷酸溶液为流动相,用外标法对有效成分进行定性、定量分析。甲酰胺基嘧磺隆线性相关系数为0.999 9;标准偏差为0.36;变异系数为1.09%、0.81%;平均回收率为102.11%。结果表明,此检测方法灵敏、快速,适用于30%甲酰胺基嘧磺隆水分散粒剂的含量检测。     

砜嘧磺隆在环境中的降解行为研究进展

评述了砜嘧磺隆的理化性质、残留测定方法及其在环境中的代谢降解研究进展,归纳了砜嘧磺隆的残留分析方法如气相色谱法、高效液相色谱法和液质联用法及其在消解动态研究中的应用,总结了砜嘧磺隆在植物、水、土壤等环境中的降解产物及其途径,提出了今后需进一步研究明确的问题。     

25%砜嘧磺隆水分散粒剂在亚麻田中的除草效果及安全性评价

亚麻田中18.75g a.i.／hm^2砜嘧磺隆水分散粒剂的除草试验表明：药后50d,杂草鲜重防效达54％～99％,与对照相比达极显著差异。在本试验条件下,药后50d内,该药会稍稍抑制亚麻生长,表现出处理的苗矮于对照。但后期这个抑制会逐渐减轻或消除,亚麻生长正常,收割时植株高度与对照没有显著差异。因此,砜嘧磺隆对亚麻安伞,除草效果也好,可用于亚麻田除草。     

苄磺隆 吡嘧磺隆泡腾片剂 毒死蜱水胶囊悬浮剂通过安徽省科技厅鉴定

2003年11月15日，安徽省科技厅组织专家在合肥市对安徽省国家农药剂型工程技术中心承担的国家“十五”农药科技攻关计划专题“苄磺隆、吡嘧磺隆泡腾片剂、毒死蜱水胶囊悬浮剂研究”(编号：2001BA308A15-01)进行了鉴定，与会专家认真听取了专题组的工作报告和技术报告，审阅了有关技术资料，考察了试验装置，经认真讨论，形成鉴定意见如下：     

6.25%酰嘧·甲碘隆水分散粒剂的液相色谱法分析

采用高效液相色谱法,以乙腈+磷酸水溶液为流动相,使用SB—C_(18)为填料的不锈钢柱和紫外检测器,检测波长230 nm,对酰嘧磺隆和甲基碘磺隆钠盐进行定量分析。结果表明,酰嘧磺隆和甲基碘磺隆钠盐标准偏差为0.044、0.022,变异系数为0.87%、1.70%,平均回收率为99.2%、98.7%,线性相关系数为0.999 1、0.998 5。     

甲硫嘧磺隆在小麦及土壤中残留的分析方法

建立了一种小麦和土壤中甲硫嘧磺隆残留的检测方法,采用层析柱和SPE小柱对样品进行净化、萃取,采用C18柱,以乙腈-0.5%冰乙酸混合溶剂为流动相,于236nm检测。在选定条件下该方法的最小检出量为0.35ng,籽粒和土壤中甲硫嘧磺隆的最低检测浓度为0.018mg/kg,植株中甲硫嘧磺隆的最低检测浓度为0.050mg/kg,甲硫嘧磺隆的质量浓度在0.1～5.0mg/L之间线性关系良好。在土壤和籽粒中以0.02、0.2、2.0mg/kg进行空白样品添加试验,平均回收率为92.14%～96.41%,变异系数为3.15%～9.45%之间,在小麦植株中以0.05、0.5、2.0mg/kg进行空白样品添加试验,平均回收率为86.93%～94.80%,变异系数为6.28%～8.30%之间。该方法的灵敏度、准确度、精密度均符合农药残留技术测定要求。     

咪鲜胺在粤浙两地水稻和土壤中残留动态

为了评价咪鲜胺在水稻上使用后的残留动态及环境安全性，在广东、浙江两地同时进行了咪鲜胺在水稻上的残留动态试验。结果表明：在广东地区，咪鲜胺在植株中的半衰期为2．59d，在土壤中的半衰期为2．46d，在稻田水的半衰期为0．46d；在浙江地区，咪鲜胺在植株中的半衰期为3．08d，在土壤中的半衰期为1．89d，在稻田水的半衰期为1．52d。收获的水稻糙米中咪鲜胺最终残留量均低于0．5mg／kg。     

啤酒厂废渣制有机-无机复混肥在水稻上的应用

利用啤酒厂废渣开发出 1种水稻专用有机无机复混肥 ,并将其对水稻的增产效果做了田间试验。试验结果表明 ,本肥施用效果明显优于当地习惯施肥和无机复混肥 ,主要通过促进植株分蘖提高成穗率而增产 ,增产幅度达 14 %。     

Bioethanol production from rice hull and evaluation of the final solid residue

The objective of this research was to produce bioethanol from rice hulls and to evaluate the recovery and potential use of the residue resulting from the enzymatic hydrolysis step before fermentation. Acid pretreatment and enzymatic hydrolysis were studied for saccharification of polysaccharides. Fermentation was conducted for up to 24?h with Saccharomyces cerevisiae yeast. After process optimization, it was possible to produce >7.0?mg?mL^?1 of ethanol after only 2?h of reaction. Characterization of the solid residues from the hydrolyzed rice husk and the in natura rice husk showed that these solids have different characteristics and present different adsorption potentials because the residue has higher silica content. The product has potential use in industrial or laboratorial adsorption processes. The results from this study offer support for the potential use of rice husks for bioethanol generation and use the solid residue from hydrolysis for adsorption.     

25%吡蚜酮·噻虫嗪悬浮剂在水稻生态系统中的残留检测和消解动态

运用高效液相色谱分析技术测定25%吡蚜酮·噻虫嗪悬浮剂在稻田水、土壤、植株和糙米中的消解动态和最终残留。吡蚜酮在稻田水、土壤和植株中的消解动态方程分别为c=0.134e^-0.12t,C=1.377e^-0.13t及C=0.741e^-0.10t。噻虫嗪在稻田水、土壤和植株中的消解动态方程分别为C=0.114e^-0.12t,C=1.118e^-0.10t及C=0.626e^-0.12t。最终残留结果显示,25%吡蚜酮·噻虫嚷悬浮剂施用剂量为0.0525～0.0788g/m²时,施药距水稻的安全收获间隔期为21d。     

Methanogens in paddy rice soil

The population, methanogenic activities and dominant species of methanogenic bacteria in paddy rice soils under different conditions were studied. Application of fertilizer, especially organic manure and submergence with deep water increased the population and methanogenic activities of methanogenic bacteria in rice soils. No large differences was observed among the population of methanogen in rice soils from different depths of 0-5, 5-13 and 13-18 cm. Soils, which developed from different parent material and had various use history, had notably different cell numbers and activities of methanogenic bacteria. Methanogenic activities in soils developed from fluvo-aquic soil were obviously higher than those in soils developed from quaternary red soil and coastal saline soil, and those in upland soil were pronounced lower than those in rice soil. The methanogenic bacteria that survived in air-dried rice soil could form methane after addition of water and incubation. The dominant species of methanogens were Methanobacterium formicicum, Methanobrevibacter sp., Methanosarcina mazeii and Methanosarcina barkeri. This revised version was published online in August 2006 with corrections to the Cover Date.     

Nitrous oxide emission from a rice paddy field in Japan

The flux of nitrous oxide (N₂O) from a rice paddy field to the atmosphere was measured at Ryuhgasaki experiment station in Ibaraki Prefecture of Japan by closed chamber method, from the summer of 1992 to the summer of 1993. During the rice-cultivated and flooding periods when methane (CH₄) was emitted, no emission or uptake of N₂O was measured because the flux values were below the detection limits. After the final water drainage for harvest in August or September, N₂O began to emit from the soil surface while the emission of CH₄ was stopped, and N₂O was emitted continually until the re-flooding day in the following spring. In the first few months after the final water drainage, the N₂O flux was in the range of 10–20 μgN/m²/hour, then in the latter several months during the cold season, the N₂O flux was less than 10 μgN/m²/hour. The vertical profiles of N₂O, CO₂ and CH₄ concentrations in the plowed layer of the soil down to a depth of 20 cm, were also measured six times in the fallow season. The maximum concentrations of N₂O and CO₂ were found in the plowed layer in the early period, and which demonstrates that most of the N₂O was produced in the plowed layer through nitrification, due to the decomposition of organic matter accumulated in the plowed layer during the rice-growing and water-flooding period. On the contrary, the vertical profiles in the cold season showed a gradual increase in the concentrations of N₂O and CO₂ in the plowed layer. It clearly indicates that a small amount of N₂O was emitted to the atmosphere by diffusion through the plowed layer from the sub-soil layer where a large source of N₂O was expected to exist. This revised version was published online in August 2006 with corrections to the Cover Date.     

阿维菌素在稻米中的残留检测

用乙酸乙酯和乙腈提取稻米中的阿维菌素,通过FLD检测器、高效液相色谱仪测定阿维菌素残留。结果表明,采用乙酸乙酯与乙腈提取较好,建立了快速测定稻米中阿维菌素残留的分析方法,具有良好的灵敏度与回收率。阿维菌素最小检出量为1.4×10-11g,糙米中阿维菌素最低检测浓度为0.001 mg/kg,平均回收率为82.38%~82.66%,RSD 9.8%~10.5%,可满足农药残留分析的要求。     

Effect of crop residue management on nitrogen dynamics and balance in a lowland rice cropping system

Two field experiments were conducted in a rice–fallow–rice cropping sequence during consecutive dry and wet seasons of 1997 on a Fluvic Tropaquept to determine the fate and efficiency of broadcast urea in combination with three residue management practices (no residue, burned residue and untreated rice crop residue). Ammonia volatilization losses from urea (70 kg N ha^–1) broadcast into floodwater shortly after transplanting for 11 d were 7, 12 and 8% of the applied N from no residue, burned residue and residue treated plots, respectively. During that time, the cumulative percent of N₂ + N₂O emission due to urea addition corresponded to 10, 4.3 and nil, respectively. The ¹⁵N balance study showed that at maturity of the dry season crop, fertilizer N recovery by the grain was low, only 9 to 11% of the N applied. Fifty to 53% of the applied ¹⁵N remained in the soil after rice harvest, mainly in the upper 0–5 cm layer. The unaccounted for ¹⁵N ranged from 27 to 33% of the applied N and was unaffected by residue treatments. Only 4 to 5% of the initial ¹⁵N-labeled urea applied to the dry season rice crop was taken up by the succeeding rice crop, to which no additional N fertilizer was applied. Grain yield and N uptake were significantly increased (P=0.05) by N application in the dry season, but not significantly affected by residue treatments in either season.     

Nitrogen in percolation water in paddy fields with a rice/wheat rotation

Nitrogen in percolation water was observed in paddy field soil under rice/wheat rotation. Different N-application rates were designed. Porous pipes were installed in triplicate at depths of 30, 60 and 90 cm to collect the water in the period of wheat growth. Suction cups were installed in triplicate at the same depths to collect the water during the period of rice growth. NH₄ ⁺, NO₃ ^- and total N in the water were analysed with a continuous-flow nitrogen analyzer. Results showed that nitrate was the predominant form of nitrogen in percolation water during the period of wheat growth. Nitrate leaching was high in early spring after the `tillering fertilisation'. More than 50 mg l^-1 of nitrate concentration in percolation water was observed for 30 and 60 cm in depth and more than 15 mg l^-1 were observed for 90 cm. The concentration decreased quickly and was very low, less than 2 mg l^-1 usually, in the earring stage of wheat. Nitrate in water was low, less than 1.5 mg l^-1 usually, when the field was flooded during the period of rice growth. Some soluble organic N existed in the water. Nitrate in percolation water increased when the field was drained. The leaching loss of nitrogen during winter wheat growth period was estimated to be about 3.4% of the N-fertiliser applied at the normal application rate of farmers; for the rice growth period it was around 1.8%. Although a reduced N-application decreased N leaching, it caused a marked decrease in crop yield.     

丁子香酚在番茄和土壤中的残留动态

采用田间试验的方法,研究了0.3%丁子香酚可溶液剂在番茄上的残留动态和最终残留,用带紫外检测器的液相色谱测定了丁子香酚的残留量。丁子香酚的最低检出量为3×10-10g,在番茄和土壤中的最低检出浓度均为0.003mg/kg。在番茄和土壤中的平均回收率为93.2%￣112.5%,变异系数为1.2%￣14.0%,符合农药残留分析的要求。试验结果表明:丁子香酚在番茄和土壤中的消解很快,其半衰期分别为9.5h和16.5h;0.3%丁子香酚可溶液剂按推荐剂量5.3ga.i./hm2和推荐剂量的1.5倍8.0ga.i./hm2使用3、4次,末次施药距收获间隔1、2、3d,丁子香酚在番茄中的残留量为0.012￣0.028mg/kg,土壤中为ND(<0.003)-0.084mg/kg;该农药属易分解农药(T1/230d),按推荐剂量使用是安全的。