排序方式： 共有18条查询结果，搜索用时 15 毫秒
1.
基于SPE与SPATT的水体中麻痹性贝类毒素检测方法构建与应用 总被引：1，自引：0，他引：1
为实现麻痹性贝类毒素(paralytic shellfish poisoning,PSP)的实时监控与提前预警,本研究构建了基于固相萃取技术(solid phase extraction,SPE)与固相吸附毒素跟踪技术(solid phase adsorption toxin tracking,SPATT)的水体中PSP检测方法,重点优化了吸附材料及前处理方法,评价了回收率、检出限等指标,并将方法应用于2019年春季秦皇岛山海关海域PSP消长过程的监测中,比较评估了两种方法的监控预警效果。结果表明:SPE方法选用ENVI-Carb 500mg/6mL固相萃取柱,过样体积为50mL,13种PSP组分的平均回收率为82.2%±10.0%、检出限为4.0-20.0ng/L;SPATT方法选用SP207大孔吸附树脂,洗脱时间为静置Id最佳,整体回收率约为9.2%;在实际应用中,结合产毒藻密度及贻贝富集毒素含量的变化,发现SPE方法的检测结果可实时表征海域PSP风险状况,对于贻贝中PSP的预警效果也显著优于SAPTT方法,后者不仅因监控方式相对滞后一个监测周期,且灵敏度及准确性均较差。对于秦皇岛海域,当SPE方法检测结果达到100ng STX eq/L时,该海域贻贝中PSP残留将具有潜在的食用安全风险,跟踪过程表明这一阈值可提前两周预警贻贝富集毒素含量超出我国限量标准(800μg STX eq/kg),这对于强化风险警示并制定防范措施具有积极作用。 相似文献
2.
Radiation exposure and Mission Strategies
for Interplanetary Manned Missions (REMSIM) 总被引：1，自引：0，他引：1
C. Cougnet N. B. Crosby S. Eckersley C. Foullon V. Guarnieri S. Guatelli D. Heynderickx A. Holmes-Siedle C. Lobascio S. Masiello P. Nieminen G. Parisi P. Parodi M. A. Perino M. G. Pia R. Rampini P. Spillantini V. Tamburini E. Tracino 《Earth, Moon, and Planets》2004,94(3-4):279-285
Cosmic radiation is an important problem for human interplanetary missions. The “Radiation Exposure and Mission Strategies for Interplanetary Manned Missions–REMSIM” study is summarised here. They are related to current strategies and countermeasures to ensure the protection of astronauts from radiation during interplanetary missions, with specific reference to: radiation environment and its variability; radiation effects on the crew; transfer trajectories and associated fluences; vehicle and surface habitat concepts; passive and active shielding concepts; space weather monitoring and warning systems. 相似文献
3.
Dan Zhang Hui Liu Ying Liang Cheng Wang Hecheng Liang Hesheng Cai 《Frontiers of Earth Science》2009,3(1):73-79
Samples of groundwater were collected from 17 sites in the Jianghan plain in July 2007. Sixteen phthalate esters (PAEs) were
detected in samples collected by using solid-phase extraction (SPE)-gas chromatography (GC). The results show that there were
one or several PAEs in all the samples, and the concentrations of total PAEs ranged from 80.12 to 1882.18 ng/L. Four PAEs,
i.e. di-isobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), bis (2-ethoxyethyl) phthalate (BEEP) and di (2-ethylhexyl)
phthalate DEHP) were the dominant species. Among these, DIBP, DBP and DEHP concentrations were closely related to the water
supply from the Yangtze River, Hanjiang River and Honghu Lake. However, the distribution of BEEP was irregular, which may
be due to the application of some kind of products containing BEEP in the related areas. PAE distribution was irrelevant to
the electrical conductivity and sample depth. 相似文献
4.
以青藏高原地区的大柴旦盐湖湖表卤水为研究对象,采用不同的固相萃取(Solid phase extraction,SPE)材料(HLB,PPL,ENVI-18,ENVI-Carb,XAD8和XAD4)对大柴旦盐湖湖表卤水中DOM进行了分离和富集,初步建立了从高盐体系盐湖卤水中高效分离富集出具有代表性的溶解性有机质(Dissolved organic matter,DOM)的方法,系统的考察了pH,上样体积,柱流速和洗脱溶剂对DOM回收率的影响。结合傅里叶变换红外光谱分析(Fourier transform infrared spectroscopy,FTIR)、热裂解—气相色谱—串联质谱分析(Pyrolysis-gas chromatography-mass spectrometry,Py-GC/MS)进一步对盐湖卤水分离物进行了谱学表征。研究结果表明,盐湖卤水在酸性条件下(pH=2),柱流速为0.5 mL/min时有助于吸附剂对DOM的吸附,而随着上样体积的增加,DOM的回收率逐渐下降,而甲醇是比较理想的洗脱剂。大柴旦盐湖湖表卤水中的DOM主要以芳香类,碳水化合物以及部分脂肪族化合物为主,而含氮类化合物含量较少。 相似文献
5.
Xiamen Western Bay‘s water and sedimem quality were studied by detemaining thelevels of sixteen polycyclic amrrmtic hydrocarbons PAHs in water, porewater and sediment samples from nine locations in the bay. Total PAH concentrations varied from 106 to 945 ng/1 in water, below detectionto 3548 ng/1 in porewater, and 247 to 480 ng/g dry weight in surface sediments. PAHs levels in porewaterwere higher than those in surface water, due to the preference of these hydrophobic compounds for sedimentary phase instead of water. Such a concentration gradient implies a potential flux of pollutants fromsediments to overlying water. The PAils levels in sediments were one to several orders of magnitude lowerthan those in 1993, suggesting their decreased input in recent years and possible degradation with time. 相似文献
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8.
Michaela Ventker Friedrich Werres Peter Balsaa Peter Winterhalter Horst Overath 《洁净——土壤、空气、水》2004,32(1):40-47
Determination of Organophosphorus Pesticides in Water by HPLC‐MS‐MS In the EC Water Framework Directive 2000/60/EG and in CEC 76/464/EEC there are 16 organophosphorus pesticides (insecticides and acaricides) listed which belong to so‐called priority substances. The committed quality aims of these substances frequently require maximum concentrations below 0.1 μg/L. In this paper a HPLC‐MS‐method is described. The reported limits of determination of organophosphorus pesticides are lower than the demanded limits. High analytical sensitivity is reached by solid‐phase extraction (SPE) and by injecting large volumes. For some of these substances no sample enrichment is needed and low detection limits are obtained by direct injection of the original water sample. 相似文献
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对土壤样品的前处理技术进行了研究。采用加速溶剂萃取法(ASE)提取土壤中有机氯农药和多氯联苯类化合物,并且与索氏提取结果进行了对比,结果表明,ASE完全能取代传统的索氏提取方法。对固相萃取(SPE)柱净化的不同填料进行了实验筛选。比较了浓硫酸磺化法和SPE柱净化法对土壤中有机氯农药及多氯联苯的净化效果。优化了有机氯农药、多氯联苯凝胶渗透色谱(GPC)的净化条件。当样品基质比较复杂时,采用凝胶渗透色谱结合固相萃取柱的前处理方法,能得到很好的净化效果。土壤样品中持久性有机污染物采用加速溶剂提取结合固相萃取前处理过程的回收率为68%~106%,精密度小于7.7%。 相似文献