bluuebunny/crossref_metadata_2025_split huggingface dataset:
Qualitative and quantitative analysis of low molecular weight compounds by ultraviolet matrix‐assisted laser desorption/ionization mass spectrometry using ionic liquid matrices
Authors: Zabet‐Moghaddam Masoud , Heinzle Elmar , Tholey Andreas 
Published: January 2004

AbstractA major problem hampering the use of matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry for quantitative measurements is the inhomogeneous distribution of analytes and matrices in solid sample preparations. The use of ionic liquids as matrices for the qualitative and quantitative analysis of low molecular weight compounds like amino acids, sugars and vitamins was investigated. The ionic liquid matrices are composed of equimolar combinations of classical MALDI matrices (sinapinic acid, α‐cyano‐4‐hydroxycinnamic acid or 2,5‐dihydroxybenzoic acid) with organic bases. These matrix systems allow a homogenous sample preparation with a thin ionic liquid layer having negligible vapour pressure. This leads to a facilitated qualitative and quantitative measurement of the analytes compared with classical solid matrices. Copyright © 2003 John Wiley & Sons, Ltd.
Solid‐phase microextraction combined with surface‐enhanced laser desorption/ionization introduction for ion mobility spectrometry and mass spectrometry using polypyrrole coatings
Authors: Wang Yan , Walles Markus , Thomson Bruce , Nacson Sabatino , Pawliszyn Janusz 
Published: January 2004

AbstractThe successful application of polypyrrole (PPY) solid‐phase microextraction (SPME) coatings as both an extraction phase and a surface to enhance laser desorption/ionization (SELDI) of analytes is reported. This SPME/SELDI fiber integrates sample preparation and sample introduction on the tip of a coated optical fiber, as well as acting as the transmission medium for the UV laser light. Using ion mobility spectrometry (IMS) detection, the signal intensity was examined as a function of extraction surface area and concentration of analyte. The linear relationship between concentration and signal intensity shows potential applicability of this detection method for quantitative analysis. Extraction time profiles for the fiber, using tetraoctylammonium bromide as test analyte, illustrated that equilibrium can be reached in less than one minute. To investigate the performance of the PPY coating, the laser desorption profile was studied. The fiber was also tested using a quadrupole time‐of‐flight (Q‐TOF) mass spectrometer with leucine enkephalin as test analyte. Since no matrix was used, mass spectra free from matrix background were obtained. This novel SPME/SELDI fiber is easy to manufacture, and is suitable for studying low‐mass analytes because of the intrinsic low background. These findings suggest that other types of conductive polymers could also be used as an extraction phase and surface to enhance laser desorption/ionization in mass spectrometry. Copyright © 2003 John Wiley & Sons, Ltd.
On‐line identification of phenanthroindolizidine alkaloids in a crude extract from Tylophora atrofolliculata by liquid chromatography combined with tandem mass spectrometry
Authors: Cui Lijie , Abliz Zeper , Xia Min , Zhao Liyan , Gao Song , He Wenyi , Xiang Yun , Liang Feng , Yu Shishan 
Published: January 2004

AbstractElectrospray ionization multi‐stage tandem mass spectrometry (ESI‐MSn) and liquid chromatography coupled with sequential mass spectrometry (LC/MSn) were applied to identify trace‐level phenanthroindolizidine alkaloids in crude extracts from Tylophora atrofolliculata. Based on the relationship between the characteristic fragmentation reactions and the structural features of related compounds of known structure from this plant, the bioactive crude extract was analyzed in detail by positive and negative ion ESI‐MSn, LC/UV‐MS and LC/MSn techniques. A total of nine constituents in the crude extract were identified rapidly, including several isomers; seven of these constituents are new and two are known compounds. The structures of four of these constituents were subsequently confirmed by nuclear magnetic resonance (NMR) and accurate mass measurements using high‐resolution fast‐atom bombardment mass spectrometry (FAB‐HRMS). Copyright © 2003 John Wiley & Sons, Ltd.
A new method for determining δ13C and δD simultaneously for CH4 by gas chromatography/continuous‐flow isotope‐ratio mass spectrometry
Authors: Potter Joanna , Siemann Michael G. 
Published: January 2004

AbstractA continuous‐flow technique has been developed to analyse the δD and δ13C values for CH4 from gas samples, in a single run. This is achieved by splitting the sample gas stream and directing the streams simultaneously through a CuNiPt combustion reactor and an alumina pyrolysis reactor. The CO2 from CH4 combustion is trapped in a liquid nitrogen trap while the H2 exiting the pyrolysis reactor is directed to the mass spectrometer for δDCH4 determination. The CO2 is then sublimed and directed to the mass spectrometer for δ13CCH4 determination. Sample runs take approximately 10 minutes. This technique gives accurate δ13CCH4 results to within ±0.3–0.5‰ and δDCH4 results to within ±2–5‰. Injection volumes between 0.5 and 2.5 μL of CH4, equivalent to between 20 and 100 nmol CH4, are required for accurate δ13C and δD analyses, respectively, using sample injection into a split flow with a split ratio of 10. This method provides rapid, accurate and reproducible results on multiple sample runs and is, therefore, an ideal method for analysing natural gas samples from a variety of sources. Copyright © 2003 John Wiley & Sons, Ltd.
Headspace solid‐phase microextraction with gas chromatography and mass spectrometry in the investigation of volatile organic compounds in an ectomycorrhizae synthesis system
Authors: Menotta Michele , Gioacchini Anna M. , Amicucci Antonella , Buffalini Michele , Sisti Davide , Stocchi Vilberto 
Published: January 2004

AbstractEctomycorrhizae formation represents one of the most significant steps in the truffle life cycle and is determined by a complex molecular signaling between two symbionts. In order to understand the molecular pathway of ectomycorrhiza development, we focused on the signaling interaction between the ectomycorrhizal fungus Tuber borchii Vittad. and the Tilia americana L. plant roots. The medium of a pre‐symbiotic (T. americana–T. borchii) in vitro system was analysed by headspace solid‐phase microextraction coupled with gas chromatography and mass spectrometry. In total, 73 volatile organic compounds (VOCs) were identified. Twenty‐nine of these VOCs were produced only during the interaction phase between the two partners, leading to a hypothesis that these molecules might act as molecular messengers in order to pilot the ectomycorrhizae formation. Copyright © 2003 John Wiley & Sons, Ltd.
Simultaneous co‐extraction of organometallic species of different elements by accelerated solvent extraction and analysis by inductively coupled plasma mass spectrometry coupled to liquid and gas chromatography
Authors: Wahlen Raimund , Catterick Tim 
Published: January 2004

AbstractThis paper describes the development of an accelerated solvent extraction methodology that is capable of simultaneously extracting organometallic species of As, Sn and Hg in a semi‐automated manner. Accelerated solvent extraction (ASE) methods based on previous research on the separate extraction of organotin and ‐arsenic species in our laboratory were adapted for the co‐extraction of six different species from an oyster tissue certified reference material (BCR 710). For the first time, the extraction of MeHg by this technique is also investigated. The proposed ASE conditions employed 50% acetic acid in methanol at a temperature of 100°C with up to five consecutive extraction cycles of 3 minutes. Extraction efficiencies for organoarsenic species ranged from 80% (dimethylarsinic acid, DMA) to 99% for arsenobetaine (AsB). Species of toxicological interest, such as dibutyltin (DBT), tributyltin (TBT) and methylmercury (MeHg), were extracted with mean recoveries of 81, 84 and 76%, respectively. The extracted species were analysed by gas chromatography/inductively coupled plasma mass spectrometry (GC/ICPMS; DBT, TBT and MeHg) and liquid chromatography/inductively coupled plasma mass spectrometry (LC/ICPMS; MMA, DMA, AsB) after ethylation with sodium tetraethylborate or dilution with water, respectively. In addition to those species for which the extraction efficiency was assessed during this study, a further five arsenic species (arsenite, arsenate and three unidentified species), as well as monobutyltin (MBT) and mono‐, di‐ and triphenyltin, could also be extracted from other matrices. The developed ASE method provides a significant improvement over many currently available routine monitoring methods for trace element speciation due to the fact that it is capable of extracting several species of toxicological interest simultaneously and quantitatively. Copyright © 2003 John Wiley & Sons, Ltd.
The Froude number stick, an evaluation
Authors: Seip Knut Lehre 
Published: January 2004

AbstractThis paper examines whether horizontal free surface flow patterns can reveal bulk river flow characteristics, such as the Froude number. To do this, the Froude number was measured between 0.2 and 1.2 by visually observing the flow patterns around a wooden stick, the so‐called ‘Froude stick’ described in the literature. The stick has been hypothesized to estimate the Froude number at the transition between subcritical and supercritical flow based on free‐surface flow patterns. The study objective was twofold: to obtain (i) a measure of the Froude number independent of estimates of water velocity and stream depth; and (ii) a tool that would allow the field biologist to assess hydrodynamic properties of streams. The results show that the stick measures only water velocity. As water velocity increases from about 0.2 m s−1, to 0.45 m s−1, an obtuse V‐shaped flow pattern around the stick obtains a right‐angle that is easy to detect by the naked eye, and wavelets upstream of the stick are more than 1 cm wide. With increasing water velocities the V‐shaped flow pattern becomes pointed, and at velocities a little larger than 1.0 m s−1 the upstream wavelets disappear. Copyright © 2004 John Wiley & Sons, Ltd.
Reconstruction of the characteristics of a natural alluvial river–floodplain system and hydromorphological changes following human modifications: the Danube River (1812–1991)
Authors: Hohensinner S. , Habersack H. , Jungwirth M. , Zauner G. 
Published: January 2004

AbstractBased on detailed historical surveys from 1812, the natural riverine landscape of a 10.25‐km‐long reach of the Danube River in the Austrian Machland region prior to channelization is analysed. Anthropogenically induced changes of fluvial dynamics, hydrological connectivity and aquatic habitat composition are discussed, comparing the situations following channelization (1925) and flow regulation (1991). In 1812 the alluvial river–floodplain system of the Danube River comprised a highly complex channel network, numerous gravel bars and extensive islands, with the main channel and side arms (eupotamon) representing about 97% of the entire water surface at low flow. The floodplain was characterized by relatively flat terrain and numerous natural trenches (former active channels) connected to the main channel. These hydromorphological conditions led to marked expansion/contraction of the water surface area at water level fluctuations below bankfull (‘flow pulse’). The high degree of hydrological connectivity enabled intensive exchange processes and favoured migrations of aquatic organisms between the river and floodplain habitats over a period of approximately 90 days per year. Overall in 1812, 57% of the active zone (active channels and floodplain) was inundated at bankfull water level.Channelization and construction of hydropower plants resulted in a truncated fluvial system. Consequently, eupotamal water bodies decreased by 65%, and gravel/sand bars and vegetated islands decreased by 94% and 97%, respectively, whereas the area of the various backwaters doubled. In 1991 the former ‘flow pulse’ was halved due to artificial levees and embankments, greatly diminishing hydrological connectivity and decoupling large areas of the floodplain from the main channel. Active overflow, formerly playing an important role, is now replaced by backwater flooding and seepage inflow in isolated water bodies. Copyright © 2003 John Wiley & Sons, Ltd.
Habitat loss as the main cause of the slow recovery of fish faunas of regulated large rivers in Europe: the transversal floodplain gradient
Authors: Aarts Bram G. W. , Van Den Brink Fred W. B. , Nienhuis Piet H. 
Published: January 2004

AbstractIn large European rivers the chemical water quality has improved markedly in recent decades, yet the recovery of the fish fauna is not proceeding accordingly. Important causes are the loss of habitats in the main river channels and their floodplains, and the diminished hydrological connectivity between them.In this study we investigate how river regulation has affected fish community structure in floodplain waterbodies of the rivers Rhône (France), Danube (Austria), Rhine and Meuse (The Netherlands). A typology of natural and man‐made aquatic habitats was constructed based on geomorphology, inundation frequency and ecological connectivity, along the transversal river–floodplain gradient, i.e. perpendicular to the main stream of the river. Fish species were classified in ecological guilds based on their flow preference, reproduction ecology and diet, and their status on national red lists was used to analyse the present state of the guilds and habitats.Ecological fish guilds appear to be good indicators of ecological integrity and functioning of river–floodplain systems. A transversal successional gradient in fish community structure that bears some resemblance to the gradient found in natural rivers can still be discerned in heavily regulated rivers. It resembles the longitudinal river gradient; even some predictions of the River Continuum Concept are applicable. Overall, richness and diversity of species and ecological guilds decrease with decreasing hydrological connectivity of floodplain waterbodies.Anthropogenic disturbances have affected fish species unevenly: guilds of specialized species that are highly adapted to specifically riverine conditions have declined far more than generalist species. Fish habitats in the main and secondary channels have suffered most from regulation and contain the highest percentage of threatened species. Rheophilic fishes have become rare because their lotic reproductive habitats are severely degraded, fragmented, absent or unreachable. Limnophilic fishes have become rare too, mainly as a result of eutrophication. Eurytopic fishes have become dominant everywhere. Copyright © 2003 John Wiley & Sons, Ltd.
Characteristics and temporal variability of large woody debris trapped in a reservoir on the River Rhone (Rhone): implications for river basin management
Authors: Moulin B. , Piegay H. 
Published: January 2004

AbstractWoody debris is a structural element of river systems, which provides habitats for aquatic communities but may enhance flooding frequency and damage infrastructure. An abundant scientific literature highlights the role of the wood, particularly in the fields of ecology and geomorphology. In order to find a balance between woody debris preservation and reintroduction for ecological purposes, and the need for channel clearing for risk management, more research is now needed to understand woody debris delivery residence time and transport dynamics in regulated rivers.This work uses reservoirs, which trap woody debris, to determine its geographical origin and temporal variability in relation to the flow regime. This approach is illustrated by data collected on the Genissiat dam on the upper Rhône river (France), which traps all the woody debris even during high floods.The results show that the wood input increases with flood frequency but also depends on the position of the flood event in the hydrological series. The wood load is significantly high and removed from the reservoir when the flood recurrence attains one in 1.5 years. Qualitative description of the wood extracted from the reservoir indicates that 83% of the pieces, whatever the size, have a natural origin (broken, cut by beaver) and 17% has been cut by humans. The large pieces of wood (diameter >12.5 cm) more frequently have a human origin (40%).Large pieces with roots are infrequent (10%) underlining the low contribution of bank erosion. Most of the pieces are strongly smoothed, without any branches, roots and bark confirming the effect of physical breakage of high energy rivers. Amongst 503 samples, 45% have a riparian origin (Populus, Fraxinus, Alnus). Copyright © 2003 John Wiley & Sons, Ltd.
Systems/operational research and sustainable development: towards a new agenda
Authors: Midgley Gerald , Reynolds Martin 
Published: January 2004

AbstractAt the 2002 International Sustainable Development Research Conference in Manchester, a great number of the 53 papers presented addressed exciting methodological developments associated with action research. Many of these initiatives can be linked with the rich tradition of operational research (OR). OR and environmental planning for sustainable development share three traditions: first, both have wide boundaries in terms of clientele, range of methodological approaches used and attention to multiple (and often conflicting) values; second, both traditions have an interest in fostering interdisciplinarity; third, both OR and environmental planning are concerned with the implementation, as well as the design, of planning strategies. Given these shared traditions, we recently engaged in a systemic intervention project to explore the possibilities of improved collaboration between OR practitioners and environmental planners. In a literature review and interviews with stakeholders, three generic issues were found to recur: complexity and uncertainty (regarding the unpredictability of natural and social phenomena); multiple and often conflicting values (of those involved in environmental planning) and political effects (on those not involved in planning processes, including non‐human nature). This paper reveals a pattern of how these generic issues are perceived in the public, business and voluntary sectors, and explains how, through a series of workshops and a mini‐conference, three interrelated agendas for future action took shape. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Experiences with sustainability indicators and stakeholder participation: a case study relating to a ‘Blue Plan’ project in Malta
Authors: Bell Simon , Morse Stephen 
Published: January 2004

AbstractThe practical application of systemic sustainability analysis (SSA; Bell and Morse, 1999) as applied in a project instigated and managed by ‘Blue Plan’, one of the regional activity centres of the Mediterranean Action Plan, is set out and explained in this paper. The context in which SSA was applied and adapted to SPSA (systemic and prospective sustainability analysis) is described in the Mediterranean, primarily in Malta.The SSA process is summarized, its extension and linkage to the prospective approach is described and the comments of stakeholders in the context are added. Some preliminary outcomes are suggested. The particular focus of the paper is on the lessons learned from doing SSA/SPSA within a classic blueprint project framework. It is not assumed that SSA/SPSA is ‘finished’ or ‘definitive’. Rather, we suggest that it is a developing and changing approach that practitioners can adapt and change to meet the specific needs of the circumstances that confront them. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
What we buy, what we throw away and how we use our voice. Sustainable household waste management in the UK
Authors: Barr Stewart 
Published: January 2004

AbstractSustainable waste management is a core issue facing local and national governments. It is widely acknowledged that although producers of goods and materials have a role to play in reducing waste, the general public, in the way that we consume and utilize products, have a key role in delivering sustainable waste management. This paper supports this assertion with data from a study of waste management attitudes and reported behaviours in southwest England. The paper presents a conceptual framework for examining attitudes and behaviours towards waste management, incorporating environmental values, situational factors and psychological variables. Using this framework, the paper demonstrates the range of influences acting on attitudes and actions towards sustainable waste management practices, focusing especially on recycling behaviour. The paper argues that the framework could provide a useful tool for examining the variety of factors influencing a range of public actions relevant to sustainable development. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
The effects of potential reform of the CAP on greenhouse gas emissions from Irish agriculture: an extensification scenario
Authors: Behan Jasmina , McQuinn Kieran 
Published: January 2004

AbstractUnlike most developed countries, agriculture is the greatest single source of greenhouse gases in Ireland and accounts for approximately one‐third of the national emissions. In this paper, the future emissions of greenhouse gases from Irish agriculture are projected using an economic model of the Irish agricultural sector. Coefficients from the Intergovernmental Panel on Climate Change (IPCC) are used to convert the raw agricultural data from the economic model to emission levels. These projections are generated under two different scenarios: the first is a baseline result, which holds the present agricultural policy environment – the EU Common Agricultural Policy (CAP) – constant for the projection period. The second result is the projection of emissions under a particular policy reform scenario. The effect of this scenario on emissions is measured relative to the baseline result. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
TXRF heavy metal analysis after immobilization as PAN complexes
Authors: Kallithrakas‐Kontos N. 
Published: January 2004

Abstract1‐(‐2‐Pyridylazo)‐2‐naphthol (PAN) forms stable complexes with many metals of environmental interest. A few micrograms of PAN were immobilized in a Nafion membrane, the membrane was put on quartz reflectors and the reflectors were immersed in standard aqueous solutions containing nickel, copper, manganese and vanadium salts at very low concentrations (µg l−1 level). The reflectors were left in the solutions for many hours at constant temperature. When the equilibration stage was finished, they were cleaned with ultra‐pure water and left to dry. Analysis of the samples was performed by total reflection x‐ray fluorescence (TXRF) spectrometry. A few µg l−1 of the above metals were determined. The effects of equilibration time and temperature on the measured x‐ray yields were examined. Copyright © 2003 John Wiley & Sons, Ltd.