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1%农乐霉素悬浮剂的高效液相色谱分析 总被引:2,自引:0,他引:2
研究用高效液相色谱法分析1%农乐霉素中有效成分的含量,采用梯度流动相,检测波长为250nm。该方法在50~1000mg/L的进样范围内和峰面积呈线性,相关系数为0.9997。回收率一般在98.5%~101.3%之间,变异系数为1.66%。 相似文献
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毒死蜱在豆角、辣椒和土壤中的残留动态 总被引:7,自引:0,他引:7
采用GC测定方法,对毒死蜱在广州和海口两地的豆角、辣椒及土壤中的残留动态进行了评价。两年的试验结果表明,毒死蜱在广州豆角中的半衰期为4.30d,在豆角土壤中的半衰期为6.02d,在辣椒中的半衰期为3.99d,在辣椒土壤中的半衰期为7.2ld;毒死蜱在海口豆角中的半衰期为4.45d,在豆角土壤中的半衰期为6.34d,在辣椒中的半衰期为4.78d,在辣椒土壤中的半衰期为8.2ld。毒死蜱在正常使用剂量下,有效成分在两地豆角、辣椒和土壤中的最终残留量均低于0.5mg/kg。 相似文献
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田间试验研究表明,阿宝在玉米苗后茎叶处理4种药剂中,化除效益居于领先地位,阿宝、阿玉,玉农乐,阿特拉津对玉米生长都安全,阿宝,阿玉,玉农乐防效均在80%以上,阿特拉津在80%以下,成本费用阿特拉津<阿宝<阿玉<玉农乐;增产率阿宝,阿玉,玉农乐,阿特拉津分别为4.47%,4.47%,2.97%,阿宝经济效益高为107.18元/hm^2,其次是可玉为99.98元/hm^2,再次是玉农乐为76.20元/hm^2,阿特拉津最低为65.78元/hm^2。 相似文献
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建立了一种用高效液相色谱测定番茄与土壤中双胍三辛烷苯基磺酸盐的定量分析方法。番茄样品用正丁醇和正己烷提取,然后加三乙胺溶液进行液液分配,经硅胶柱层析净化;土壤样品用氢氧化钠-甲醇溶液提取,然后加三氯甲烷进行液液分配,经硅胶柱层析净化。甲醇-水-氨水作流动相,荧光检测器检测,外标法定量。番茄添加水平为0.2~5.0mg/kg时,回收率为70%-88%,变异系数2.1%~8.7%;土壤添加水平为0.2~5.0mg/kg时,回收率为62%-95%,变异系数3.3%-4.9%;对番茄和土壤的最低检出浓度分别是0.05、0.10mg/kg。 相似文献
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病虫清可湿性粉剂活性成分的高效液相色谱分析研究 总被引:2,自引:0,他引:2
采用C18色谱柱和和紫外检测器,对病虫清可湿性粉剂中的三种活性成分噻嗪酮、杀虫单和井冈霉素的含量进行反相高效液相色谱测定,以外标法面积定量。噻嗪酮、杀虫单和井冈霉素的变异系数分别为0.51%、0.62%、1.08%,回收率为99.45%~100.65%、95.44%~99.23%、97.25%~99.36%,线性灵0.9982,0.9985,0.9983。方法用于实样测定,结果令人满意。 相似文献
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井冈霉素对土壤可培养微生物的生态效应 总被引:6,自引:0,他引:6
土壤可培养微生物的动态变化表明,低浓度井冈霉素对细菌总数没有明显影响,较高浓度井冈霉素可促进细菌总数的增加,其中浓度在60mL/kg时,井冈霉素对细菌的刺激强度最高,为对照的220倍,过高浓度的井冈霉素(240mL/kg)对细菌总量的促进作用反而不明显。井冈霉素对土壤中放线菌数量是先刺激后抑制,刺激强度最高时,放线菌数量可增至对照的61倍左右;而最高抑制强度可使放线菌的数量降至对照的14.5%。井冈霉素对真菌的敏感性较低,只有浓度高达120、240mL/kg时,才对真菌产生明显刺激作用,最高刺激强度为同时期对照的118倍。发光菌的毒理试验表明,低浓度井冈霉素毒性很低,较高浓度时呈现较大毒性,但能在短期内恢复,而过高浓度时的井冈霉素可能对土壤微生物造成不可恢复的影响。 相似文献
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It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples. 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively.
There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized.
High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without
the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of
fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to
achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic
SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve
F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender
particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing,
and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing
or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually
preserves suspension stability during freezing.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago,
IL. Tied for first place in The John A. Gordon Best Paper Competition. 相似文献
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Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US
In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae
and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted
in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures
(release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species
(Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species
to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were
exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of
separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles
from the southeastern region of the US. 相似文献
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ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究 总被引:15,自引:0,他引:15
建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。 相似文献
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