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1.
建立基质固相分散(MSPD)辅助加压溶剂萃取(PLE)-高效液相色谱法测定土壤中16种多环芳烃的方法.土壤样品与弗罗里硅土混匀后装入萃取池,在15 MPa、120℃萃取条件下,丙酮∶二氯甲烷(1∶1,V∶V)作为萃取溶剂,静态提取5min,应用高效液相色谱法荧光检测-二极管阵列检测串联,采用外标法对其进行定量分析.结果表明:16种多环芳烃线性关系良好,相关系数均大于0.9994,利用荧光检测器与二极管阵列检测器的方法检出限分别为0.04—0.8μg·L-1、0.6—20μg·L-1,在低、中、高3个水平下的加标回收率在78.4%—105.8%范围内,测定结果的相对标准偏差为1.2%—4.1%(n=5).  相似文献   

2.
猪场废水灌溉对地下水中氮素的影响   总被引:3,自引:0,他引:3  
应用猪场废水处理工程中产出的厌氧水不同灌溉量和3个处理阶段V(出水)∶V(地下水)=1∶5混合对冬小麦-夏玉米轮作系统连续进行3年小区灌溉试验,地下水中总氮、铵态氮、硝态氮和亚硝态氮等指标的监测结果表明:(1)厌氧水不同灌溉量条件下地下水中4种氮素含量总体呈现高量厌氧水(Ha)〉中量厌氧水(Ma)〉低量厌氧水(La)的变化趋势;(2)混水灌溉处理地下水中4种氮素含量均呈V(原水)∶V(地下水)=1∶5混合(Tog)〉V(厌氧水)∶V(地下水)=1∶5混合(Tag)〉V(仿生态塘水)∶V(地下水)=1∶5混合(Teg)的变化趋势。文章的研究能够为制定合理的猪场灌溉制度提供数据支撑。  相似文献   

3.
建立了微波辅助萃取-固相微萃取-气相色谱/三重四极质谱法(MAE-SPME-GC/QQQ)同时测定土壤中多种氯代苯胺的方法.优化了多反应监测(MRM)的仪器条件,研究了微波萃取温度、保持时间、溶剂体积对萃取效果的影响,确定最佳实验条件为4 g土壤样品加入30 m L水,在100℃下微波萃取5 min.各目标物的线性范围为0.005—20μg·L-1,方法检出限为0.003—0.4 ng·g-1.测定0.5 ng·g-1和5 ng·g-1加标土壤样品,回收率为38.6%—116.4%和24.8%—82.0%,相对标准偏差为3.2%—27.7%和12.5%—22.7%(n=7).方法综合了MAE快速高效、SPME富集浓缩以及GC/QQQ抗干扰强的优势,适合于非高有机质含量土壤中氯代苯胺类残留的快速痕量分析.  相似文献   

4.
利用气相色谱-质谱联用仪(GC-MS),结合固相萃取技术,建立了同时测定污水中7种对羟基苯甲酸酯和5种甾体雌激素的定量分析方法.结果表明,目标物在40℃衍生化反应60 min可达最佳衍生化效果;最佳萃取剂净化条件为:使用HC-C18型SPE柱,p H=7条件下萃取,洗脱液为乙酸乙酯∶丙酮(1∶1,V∶V).该方法检出限(LOD)为1.8—5.7 ng·L-1,线性范围20—2000 ng·L-1(r0.990),除少量目标物回收率稍高外,大部分目标物的回收率为82.2%—128.5%,相对标准偏差介于4.4%—21.2%之间.  相似文献   

5.
混酸微波辅助萃取ICP-MS测定不同性质土壤中的重金属元素   总被引:1,自引:0,他引:1  
比较了硝酸(HNO3)、硝酸-盐酸(HNO3∶HCl=3∶1)、硝酸-盐酸-双氧水(HNO3∶HCl∶H2O2=3∶1∶1)和硝酸-盐酸-高氯酸(HNO3∶HCl∶HCl O4=3∶1∶1)等4种消解液对土壤中铅(Pb)、镉(Cd)、砷(As)、铬(Cr)、镍(Ni)、铜(Cu)和锌(Zn)等7种重金属元素的萃取效率.结果表明,硝酸-盐酸-高氯酸混合液的萃取效果最好,硝酸-盐酸混合液次之.通过对6种土壤标准物质的分析发现,除了Cr之外,其他重金属元素在土壤中的混酸微波可提取态含量与总含量接近.土壤中的Cr有一部分是以铬铁矿的形式存在,在环境中相对较为稳定,采用混酸微波可提取态的Cr来评估其对环境的危害能够获得更加准确的结果.重金属与土壤的结合强弱与成土母质相关,冲积母质的土壤中Pb、Zn和Cu的结合较强,萃取相对较难,Cd、Ni和As与土壤的结合强弱则与成土母质关系不大.采用最优的消解液萃取矿区河流底泥和土壤中的重金属,ICP-MS分析结果表明,底泥中重金属含量较高,应为尾砂冲积而成,矿区周边的土壤也受到不同程度重金属的污染.  相似文献   

6.
研究了固相微萃取(SPME)-高效液相色谱(HPLC)测定水样中痕量亚当氏剂和二苯胺的分析方法.对SPME的条件如萃取纤维、萃取时间、萃取温度、离子强度、解吸方式、解吸溶剂、解吸时间进行了优化,并用于地下水等实际水样的分析.SPME优化的条件为:选用60μmPDMS/DVB萃取纤维在室温25℃下直接萃取60min,磁力搅拌速度为1100r.min-1,然后萃取纤维在解吸室内静态解吸9min后进行HPLC分析.液相色谱分离条件为ZORBAXSBC18柱(4.6mmi.d.×250mm,5.0μm),流动相为甲醇-水(70:30,V/V),流速为1.0ml.min-1,二极管阵列检测器波长为280nm.方法线性范围为0.005mg.l-1—0.5mg.l-1(R>0.99),两种物质的检出限(S/N=3)分别为0.003mg.l-1和0.002mg.l-1.加标回收率分别在89.6%—100.4%和97.5%—100.1%(n=5)之间,相对平均标准偏差(RSD)分别在4.5%—6.2%和3.8%—6.7%之间.该方法快速、简便,无需使用有机溶剂,适于水样中痕量物质的分析.  相似文献   

7.
建立微波辅助萃取-气相色谱法同时检测裙带菜中多氯联苯和有机氯农药残留的方法.裙带菜风干、粉碎后,采用微波辅助萃取仪提取粗提液,经净化、脱酸、脱水、浓缩后,用气相色谱-电子捕获检测器进行分析检测.结果表明,本方法多氯联苯和有机氯农药的检出限分别在0.008—0.044 ng.g-1和0.029—0.273 ng.g-1之间,各组分线性相关系数均大于0.996,加标回收率为72%—131%,相对标准偏差在2%—16%之间(n=3).因此,本方法具有节省时间、减少污染、操作简单便捷等特点,可用于裙带菜等海洋藻类中多氯联苯和有机氯农药残留量的检测.  相似文献   

8.
建立了超声提取-分散液相微萃取联合气相色谱质谱法测定大气PM_(2.5)中15种邻苯二甲酸酯的方法.样品经过二氯甲烷和丙酮(1∶1,V/V)提取后,以1,2-二氯苯为萃取剂、丙酮为分散剂,运用分散液相微萃取法进一步萃取大气颗粒物PM_(2.5)中的邻苯二甲酸酯.结果显示,方法检出限为0.29—4.77 pg·m-3,最低检出限为0.96—15.74 pg·m~(-3),加标回收率为72.7%—110.9%,相对标准偏差为0.6%—9.4%,将此方法应用于苏州市某区大气PM_(2.5)中的邻苯二甲酸酯的测定,检测出大部分邻苯二甲酸酯.  相似文献   

9.
应用Sampli Q SPE-C18固相萃取小柱净化处理,利用高效液相色谱-紫外检测器(HPLC-UV)检测,建立了土壤样品中新型烟碱类杀虫剂哌虫啶的残留测定方法.优化了哌虫啶的分析条件,以选用乙腈/水比例为40∶60(V/V)作为流动相,流速为1.0 m L·min-1,采用HPLC-UV在359 nm处检测,哌虫啶的两个峰保留时间分别为4.251 min和6.526 min.在0.5×10-9—2.5×10-7g范围内,哌虫啶的进样量与色谱峰面积呈良好线性关系,相关系数为0.9993,哌虫啶的最小检出量为2.5×10-10g.土壤样品用色谱纯乙腈提取,由SPE-C18固相萃取小柱净化后.哌虫啶在土壤中的平均添加回收率为81.73%—89.05%,变异系数为3.59%—5.25%,哌虫啶最低检测浓度为2.5×10-3mg·kg-1.该分析方法灵敏、准确、操作简便,节约溶剂,对环境污染小,适合土壤中低浓度哌虫啶的残留检测  相似文献   

10.
高效液相色谱法同时测定青菜中环丙氨嗪和三聚氰胺残留   总被引:1,自引:0,他引:1  
研究并建立了同时测定青菜中环丙氨嗪和三聚氰胺残留量的高效液相色谱紫外检测分析方法。冷冻干燥并均质后的青菜样品经V(氨水):V(甲醇)=5:95的混合溶液超声辅助浸提、离心、旋转蒸发、固相萃取等浓缩净化处理后,用高效液相色谱定量。分离色谱柱为AgilentNH:柱,流动相为矿(乙腈):V(水)=90:10的混合溶液,流速为1mL·min-1,检测波长为214nm。环丙氨嗪和三聚氰胺的标准曲线在0.05~10.0mg·L-1范围内与其峰面积线性良好,相关系数不低于0.9995,在0.2~4.0mg.kg-1添加范围内,环丙氨嗪和三聚氰胺的平均回收率分别为81.26%~87.69%和78.24%~82.33%,相对标准偏差分别为2.75%~6.18%和3.99%~6.67%,方法的最低检测浓度分别为11.30和20.38μg·k-1。该方法操作简单且灵敏度高,适用于青菜样品中环丙氨嗪和三聚氰胺残留检测。  相似文献   

11.
Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación  相似文献   

12.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

13.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

14.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

15.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

16.
Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.  相似文献   

17.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

18.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  相似文献   

19.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

20.
Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.  相似文献   

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