对水中硝基苯类固相萃取效率的研究

固相萃取(SPE)作为一种新型的样品处理技术已广泛用于水中有机污染物的痕量富集,与经典的液液萃取(LLE)相比,同相萃取具有节省时间、溶剂用量少、不易乳化等优点.关于固相萃取水中杀虫剂和除草剂方面的报道很多,但应用该技术富集水中硝基苯类化合物的研究却不够深入和系统.     

使用Waters Integrity System进行除草剂／杀虫剂的化合物鉴定

环境中除草剂/杀虫剂的检测分析难度很大.Waters可提供对除草剂/杀虫剂进行化合物鉴定的全套设备和方法,用三官能团C_(18)Sep-Pak小柱,Nova-Pak分析柱,以及Integrity System可对除草剂/杀虫剂进行批量浓缩,并可很容易地从复杂化合物中进行分离和检测,以超高灵敏度进行化合物鉴定.由于IntegritySystem是结合了PDA和MS先进功能的HPLC系统,因此成为分析水中污染物的利器.用SPE(固相萃取)技术进行痕量分析世界各国政府相继降低饮用水中污染物的允许浓度,如欧共体(EEC)饮用水的分项指标为0.1μg/1,点体指标只有0.5μg/l.对如此低的含量进行分析,只能使用SPE技术进行浓缩.SPE可离线进行,也可     

水中痕量含氯除草剂的在线富集及自动样品净化的简单快速方法

在线富集分析了酸化水中的8种含氯除草剂:毒莠定,草灭平,麦草畏,灭草松,2,4-D,滴丙酸,2,4,5,-T,P三氟羧草醚.这些除草剂可以在少于2 mL的水中进行分析,运行时间在15 min以内.使用Agilent ZORBAX SB-Aq色谱柱用于捕获分析物,Agilent ZORBAX SB-C18色谱柱用于分析,一个两位六通阀用于色谱柱切换.通过毒莠定和滴丙酸的标准曲线,从而验证了水中这些农药定量方法的系统适应性.自动样品净化省去了样品制备时繁杂的固相萃取(SPE)程序.Agilent 1260 Infinity LC系统的灵敏度可以达到EPA(美国环境保护署)方法的检出限要求,而且只需使用少于EPA官方方法所要求的样品量的十分之一.     

在线SPE固相萃取、HPLC/UV检测饮用水和瓶装矿泉水中酚类

酚类物质由于有致毒性而被规定为饮用水和矿泉水中的毒性污染物,欧盟饮用水指导原则规定饮用水和矿泉水中的酚类物质不高于0.5μg·l-1,日本健康,劳动和福利部门规定饮用水中的酚类物质最高含量为5μg·l-1,美国EPA规定五氯(苯)酚最高含量为1μg·l-1,并规定11种常见酚类物质作为美国EPA首要检测的污染物质,带有UV/DAD,电化学检测器,荧光检测器的液相色谱可以对酚类物质进行检测,在线SPE固相萃取和HPLC相结合的技术,能解决传统SPE样品前处理方式的缺点,不需要购买大量SPE萃取柱和消耗大量的人力,戴安公司UltiMate(R)3000液相色谱开发出了大量先进液相色谱方法,例如二元液相,二维液相色谱和在线SPE/HPLC,配备有大体积自动进样器的一台UltiMate 3000液相色谱仪,能够进行在线固相萃取,完成检测瓶装饮用水酚类物质,用二元泵阀切换技术可以替代大体积自动进样器也能做到在线SPE固相萃取.     

叶类蔬菜有机氯农药残留测定过程中的提取和净化

用柱萃取法提取 ,气相色谱 电子捕获检测器 (GC ECD)测定蔬菜中的多种有机氯农药 .比较了不同提取溶剂对蔬菜中有机氯农药的提取效率 .就回收率而言 ,正己烷和丙酮 (V/V ,4∶1 ) >石油醚和丙酮 (V/V ,4∶1 ) >二氯甲烷和丙酮 (V/V ,4∶1 ) >纯正己烷 .用正己烷和丙酮作提取溶剂时 ,1 2种有机氯农药中有 1 0种的回收率在 80 %以上 ,变异系数在 1 %— 1 5 %之间 .不同固相萃取 (SPE)填料对有机氯农药的纯化效率为 :硅胶对目标物质的净化效率要高于硅藻土和氟罗里硅土 ,硅胶做填料时变异系数在 1 5 %以下 .因此 ,本实验认为用正己烷和丙酮 (V/V ,4∶1 )做提取剂、选择硅胶做填料能够对蔬菜中多种有机氯农药有较好的提取和净化效果 ,是一种较理想的蔬菜中有机氯农药的分析方法 .     

Occurrence and removal of N-nitrosodimethylamine and its precursors in wastewater treatment plants in and around Shanghai

Six wastewater treatment plants （WWTPs） were investigated to evaluate the occurrence and removal of N-nitrosodimethylamine （NDMA）, NDMA formation potential （FP） and four specific NDMA precursors, dimethylamine （DMA）, trimethylamine （TMA）, dimethyl- formamide （DMFA） and dimethylaminobenzene （DMAB）. DMA and tertiary amines with DMA functional group commonly existed in municipal wastewater. Chemically enhanced primary process （CEPP） had no effect on removal of either NDMA or NDMA FP. In WWTPs with secondary treatment processes, considerable variability was observed in the removal of NDMA （19%-85%） and NDMA FP （16%-76%）, moreover, there was no definite relationship between the removal of NDMA and NDMA FP. DMA was well removed in all the six surveyed WWTPs; its removal efficiency was greater than 97%. For the removal of tertiary amines, biologic treatment processes with nitrification and denitrification had better removal efficiency than conventional activated sludge process. The best removal efficiencies for TMA, DMFA and DMAB were 95%, 68% and 72%, respectively. CEPP could remove 73% of TMA, 23% of DMFA and 36% of DMAB. After UV disinfection, only 17% of NDMA was removed due to low dosage of UV was applied in WWTP. Although chlorination could reduce NDMA precursors, NDMA concentration was actually increased after chlorination.     

GC-MS/MS法结合顶空SPME测定环境水中16种多环芳烃

多环芳烃(PAHs)具有疏水性和较低的蒸汽压,以痕量浓度广泛分布于自然水体中.目前,国内外应用于水中PAHs测定的主流方法有SPE、SPME与液相及气质等联用.吸附剂种类以及为了增加PAHs的可溶性而向样品中添加的有机溶剂,对于提高SPE的萃取效率非常重要;SPME技术则更多依赖萃取头涂层,减小了样品量,同时避免了使用有机溶剂.本     

在线富集配合高效液相色谱串联质谱法分析水中的除草剂

建立了一种采用在线富集（online SPE）配合高效液相色谱串联质谱法（LC-MS-MS）快速分析水中除草剂残留的方法.测定了水中的草甘膦、溴氰菊酯、呋喃丹、阿特拉津、灭草松及2,4-D等6种化合物.该方法采用一个两位十通阀方便地实现大体积上样富集与梯度顺序洗脱的切换.6种化合物于20 min内完全分离,线性及重现性良好.在进样900μL时各种化合物的检出限均低于国家标准要求的限量,结果令人满意.     

固相萃取-液相色谱/荧光检测法同时测定水中8种烷基酚和烷基酚聚氧乙烯醚

本文通过优化色谱条件、前处理条件、样品保存条件等,建立了水中8种烷基酚(APs)和烷基酚聚氧乙烯醚(APEOs)的固相萃取(SPE)—高效液相色谱/荧光检测(HPLC-FLD)分析方法.水样经酸化(p H 2.0—3.0)后加入甲醇至20%体积分数,并以10 m L·min~(-1)速度通过HLB固相萃取小柱进行浓缩和净化,收集SPE洗脱液进行HPLC-FLD检测分析.采用Waters PAH C18色谱柱(4.6×250 mm,5.0μm),以乙腈和5 mmol·L-1醋酸铵溶液进行梯度洗脱,流速为1.0 m L·min~(-1),荧光检测的激发和发射波长分别为228 nm和300 nm.结果表明,8种组分的线性关系良好(R0.998),方法检出限为0.2—0.5μg·L-1.在低、中、高加标水平下,8种组分的回收率分别为82.5%—119.4%、92.1%—118.0%、89.7%—103.9%,平均相对标准偏差分别为5.3%、5.4%、2.9%.该方法灵敏度高、操作简单、易于推广应用,适用于水中多种APs与APEOs的同时分析.     

使用安捷伦J&W DB-35ms超高惰性色谱柱和DB-XLB色谱柱对水中低于μg·L~(-1)级的有机氯农药和除草剂进行GC/μECD法分析

本文中使用安捷伦SPEC C18AR固相萃取膜盘成功萃取了水中的有机氯农药残留和除草剂.使用双柱配置的GC/μECD系统进行检测,安捷伦JW DB-35ms UI超高惰性色谱柱作为分析柱,DB-XLB色谱柱为确认柱.该方法为浓度接近或低于最大污染限值的含氯有机物提供了高度灵敏的分析方法.根据预估的分析物萃取浓度,方法使用的校准范围为1—100 ng·mL~(-1).分别对0.01μg·L~(-1)的加标水样和一个自来水水样进行了萃取和分析,结果证明可满足水中的有机氯农药残留和除草剂的测定.     

Representation of the world's biophysical conditions by the global protected area network

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.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

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.     

Democracy versus development: New urban debates

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.     

Achieving Open Access to Conservation Science

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     

A framework to measure the wildness of managed large vertebrate populations

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.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

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.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

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.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

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.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

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.