纤维膜三相液相微萃取在测定偶氮染料降解产生芳香胺中的应用

采用纤维膜保护的三相液相微萃取（HF-LLLME）技术,对偶氮染料在人工汗液和光辐照协同作用下降解产生致癌芳香胺的分析方法进行了研究.选用苯胺、邻甲苯胺、对氯苯胺和对硝基苯胺的汗液混合溶液进行模拟样品预处理,以正辛醇为有机萃取相,在供体相pH值为9,NaC l浓度为200.gL-1,接收相为pH=1的盐酸水溶液,萃取时...     

液相色谱-质谱联用法快速测定腌桂花中6种生物胺

建立了腌桂花中腐胺、尸胺、组胺、苯乙胺、酪胺、色胺等6种生物胺含量的液相色谱-质谱联用(LC-MS/MS)检测方法.样品用乙腈水溶液(8∶2,V/V)提取,经过Carb柱净化后采用LC-MS/MS进行分析.选择Thermo Syncronis HILIC(100 mm×2.1 mm,1.7μm)作为分析柱,乙腈和水溶液(10 mmol·L-1甲酸铵和0.1%甲酸)作为流动相进行梯度洗脱.结果显示,腐胺的线性范围为10—250 ng·m L-1,其余5种生物胺的线性范围为5.0—250 ng·m L-1,相关系数(r2)均大于0.99.6种生物胺的检出限(LODs)范围为20—40μg·kg-1,定量(LOQs)范围为50—100μg·kg-1.在200、500、800μg·kg-1的3个添加水平下,6种生物胺的回收率范围为74.5%—121.5%,相对标准偏差(RSDs)范围为3.0%—8.2%.此方法灵敏度高且前处理简单,能满足腌桂花中生物胺的检测要求.     

基质固相分散-加压溶剂萃取法测定土壤中多环芳烃

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).     

加速溶剂萃取(ASE)-固相萃取(SPE)-高效液相色谱法(HPLC)测定土壤中青霉素钠

建立了一种加速溶剂萃取(ASE)-固相萃取(SPE)-高效液相色谱(HPLC)测定土壤中青霉素钠的简单、快速的方法.样品以超纯水为提取溶剂,50℃提取温度为ASE提取条件参数;HLB型固相萃取柱富集净化:6.0mL 5%甲醇淋洗、4.0mL乙腈-甲醇(1∶1)洗脱;高效液相色谱-紫外检测器(HPLC-PDA)测定,检测波长λ=191.1nm,柱温30℃,流动相为乙腈-0.1%甲酸/水(1∶1),采用等梯度洗脱程序,取得较好的检测分离效果.对0.5、2.0、8.0mg·kg-1等3个不同添加浓度水平的青霉素钠平均加标回收率范围为73.1%—89.7%,回收率相对标准偏差RSD范围为1.1%—2.9%(n=5),检出限可达235.0μg·L-1.结果表明,该方法操作简单,快速,准确度和精密度均符合质量控制要求,能够满足环境土壤样本中痕量青霉素钠检测分析的要求.     

中空纤维膜辅助离子液体液相微萃取-高效液相色谱法测定环境水体中的水杨酸

分别以l-辛基-3-甲基咪唑六氟磷酸离子液体([C8MIM][PF6])和三辛基氧化膦(TOPO)作为萃取剂与辅助萃取剂,建立了中空纤维膜辅助的两相液液微萃取-高效液相色谱测定环境水体中水杨酸(Salicylicacid,SA)的新方法.通过对中空纤维膜种类、萃取剂、供体相体积、供体相pH、离子强度和萃取时间相关参数进行优化,获得了较高的富集倍数(1653倍).方法的检出限为0.1μg.L-1,线性范围为0.5—1000μg.L-1.方法对实际样品的加标回收率为89.6%—102.4%,可应用于环境水体中痕量SA的测定.     

SPE-RRLC-MS/MS测定河水和沉积物中14种典型抗生素

针对磺胺类、喹诺酮类、四环素类、大环内酯类共14种典型抗生素,建立了水和沉积物中固相萃取-高分离快速液相色谱-串联质谱(SPE-RRLC-MS/MS)前处理方法和仪器检测方法.14种抗生素在5—100μg·L~(-1)范围内线性良好,相关系数r≥0.990.优化后的前处理方法采用乙腈/0.1 mol·L~(-1) EDTA-Mcllvaine(1∶1,V/V)作为沉积物样品中目标抗生素的提取剂,甲醇/丙酮(85∶15,V/V)作为固相萃取柱的洗脱液.表层水中14种抗生素的加标回收率为56%—117%,相对标准偏差(n=3)为0.10%—12%;沉积物中14种抗生素的加标回收率为57%—127%,相对标准偏差(n=3)为0.10%—25%.表层水和沉积物中抗生素的方法检出限分别为0.18—5.88 ng·L~(-1)和0.25—2.94 ng·g~(-1).该方法用于检测合肥市南淝河表层水和沉积物中的抗生素,5种抗生素被检出,浓度范围分别为32—308 ng·L~(-1)和2.70—329 ng·g~(-1).     

在线固相萃取-高效液相色谱法测定水中的苯脲化合物

通过在线固相萃取-高效液相色谱法快速、准确测定了EPA532方法规定的水中9种痕量苯脲化合物类杀虫剂.通过双梯度高效液相色谱系统中的上样泵,采用大体积自动进样方式,将2.5 mL水样中的被测物富集在萃取柱上;而后通过阀切换将萃取柱切换至分析流路中,进行分离、测定.上样泵的流动相为纯水和甲醇,分析泵的流动相为20 mmol·L-1甲酸铵水溶液和乙腈,流速分别为1.0 mL·min-1和0.6 mL·min-1,检测波长为245 nm,整个分析时间为20 min.方法在0.5—100μg·L-1范围线性关系良好,9种杀虫剂的线性相关系数R2≥0.9927,检出限≤0.093μg·L-1,7次平行测定保留时间RSD≤0.08%,峰面积RSD≤2.57%.该方法前处理简单,快速,重现性好,可用于环境水体和饮用水中痕量杀虫剂、除草剂等污染物的测定.     

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.     

固相萃取-液相色谱法测定食品废水中8种色素残留

建立了食品工业废水中8种合成色素残留的固相萃取-液相色谱测定方法.水样经固相萃取柱富集,氮吹浓缩定容后直接进样.采用C18色谱柱分离,以甲醇-乙酸铵(0.01mol·L^-1)溶液为流动相,进行梯度洗脱,最后利用二极管阵列检测器(DAD)进行可变波长分析,外标法定量.结果表明,8种合成色素在1.0—50mg·L^-1的浓度范围内线性良好,相关系数均大于0.999,定量限为1.6—2.4μg·L^-1.以实际废水样品为加标对象,分别考察了低、中、高三个浓度水平的加标回收率和精密度,平均加标回收率在82.3%—95.9%之间,精密度均小于5.45%.该方法准确可靠,灵敏度高,可用于食品工业废水中痕量色素残留的测定.     

离子液体双水相萃取-HPLC-MS/MS法测定环境水样中痕量3种酞酸脂类污染物

研究了离子液体双水相萃取分离环境水样中3种酞酸酯类污染物分析方法的可行性,考察了影响离子液体双水相萃取率的主要因素,在最优实验条件下:p H=4,Na H2PO4浓度为0.5 mol·L-1,离子液体加入量为2 m L,萃取时间为6 min,萃取分离了自来水、湖水和工业废水中3种酞酸酯类污染物,液相色谱-串联质谱法测定,回收率为94%—104.2%,相对标准偏差为1.7%—5.3%.方法检出限达0.7—0.99 ng.     

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     

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.     

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.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

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.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.