bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fragmentation study of salinomycin and monensin A antibiotics using electrospray quadrupole time‐of‐flight mass spectrometry
Authors: Miao Xiu‐Sheng , March Raymond E. , Metcalfe Chris D. 
Published: January 2003

AbstractThe fragmentation pathways of two selected ionophore antibiotics, salinomycin and monensin A, were studied using electrospray (ES) orthogonal acceleration quadrupole time‐of‐flight mass spectrometry in positive‐ion mode. The identity of fragment ions was determined by accurate‐mass measurements. In ES mass spectra, ion signals of relatively high intensity were observed for [M+Na]+ and [M−H+2Na]+ for each antibiotic. Each of the ion species [M+Na]+ and [M−H+2Na]+ for salinomycin and [M−H+2Na]+ for monensin A were isolated in turn and subjected to fragmentation. In the fragmentation of [M+Na]+ and [M−H+2Na]+ from salinomycin, only CC single bond cleavage and dehydration were observed. Product ion mass spectra obtained from [M−H+2Na]+ of monensin A showed that ether ring opening, CC single bond cleavage and dehydration fragmentations had occurred. Fragment ions containing two sodium atoms were observed in the product ion mass spectrum of [M−H+2Na]+ from salinomycin, but not from monensin A. Both type A (containing the terminal carboxyl group) and type F (containing the terminal hydroxyl group) fragment ions were observed in the product ion mass spectra of sodium adduct ions of salinomycin and monensin A. Copyright © 2002 John Wiley & Sons, Ltd.
An improved liquid chromatography/tandem mass spectrometry method for the determination of 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine in DNA samples using immunoaffinity column purification
Authors: Singh Rajinder , McEwan Michael , Lamb John H. , Santella Regina M. , Farmer Peter B. 
Published: January 2003

AbstractThe analysis of 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine (8‐oxodG) represents an important biomarker of oxidative stress. A sensitive method for the detection of 8‐oxodG in DNA samples has been developed that utilizes immunoaffinity column purification of 8‐oxodG followed by liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) multiple reaction monitoring (MRM) mode analysis. An internal standard of stable‐isotopically labelled 8‐oxodG containing [15N5] was added prior to the enzymatic digestion of DNA to deoxynucleosides, which was then subjected to immunoaffinity column purification followed by microbore positive ion LC/MS/MS MRM. The 8‐oxo‐7,8‐dihydroguanine (8‐oxoG) base product ion at m/z 168 was monitored following cleavage of the glycosidic bond of the 8‐oxodG [M+H]+ ion at m/z 284. Similar determinations were made for [15N5]8‐oxodG by monitoring the [15N5]8‐oxoG base product ion at m/z 173 formed from the [M+H]+ ion at m/z 289. The introduction of the immunoaffinity column purification step into the method represents a significant improvement for the accurate determination of 8‐oxodG since all artefactual peaks that are observed following the direct injection of digested DNA onto the LC/MS/MS system are removed. The identity of these artefactual peaks has been confirmed to be 2′‐deoxyguanosine (dG), thymidine (dT) and 2′‐deoxyadenosine (dA). The presence of these artefactual peaks in MRM mode analysis can be explained as a consequence of a concentration effect due to their considerably higher relative abundance in DNA compared to 8‐oxodG. The highest signal intensity was observed for the artefactual peak for dA due to the fact that the adenine base formed an adduct with methanol, which is a constituent of the mobile phase. The resulting [M+H]+ ion at m/z 284 (dA m/z 252 + CH3OH m/z 32) gave rise to a product ion at m/z 168 following the loss of deoxyribose in MRM mode analysis. Control calf thymus DNA was digested to deoxynucleosides and unmodfied deoxynucleosides were removed by immunoaffinity column purification; the enriched 8‐oxodG was determined by LC/MS/MS MRM. The level of 8‐oxodG in control calf thymus DNA was determined to be 28.8 ± 1.2 8‐oxodG per 106 unmodified nucleotides (n = 5) using 5 μg of digested DNA. The limit of detection of the microbore LC/MS/MS MRM for 8‐oxodG was determined to be 25 fmol on‐column with a signal‐to‐noise ratio of 3.5. Copyright © 2002 John Wiley & Sons, Ltd.
A top down approach to protein structural studies using chemical cross‐linking and Fourier transform mass spectrometry
Authors: Kruppa Gary H. , Schoeniger Joseph , Young Malin M. 
Published: January 2003

AbstractMass spectrometric analysis of wild‐type proteins that have been covalently modified by bifunctional cross‐linking reagents and then digested proteolytically can be used to obtain low‐resolution distance constraints, which can be useful for protein structure determination. Limitations of this approach include time‐consuming separation steps, such as the separation of internally cross‐linked protein monomers from covalent dimers, and a susceptibility to artifacts due to low levels of natural and man‐made peptide modifications that can be mistaken for cross‐linked species. The results presented here show that when a crude cross‐linked protein mixture is injected into an electrospray ionization Fourier transform mass spectrometry (ESI‐FTMS) instrument, the cross‐link positions can be localized by fragmentation and mass spectrometry on the ‘gas‐phase purified’ singly internally cross‐linked monomer. Our results show that reaction of ubiquitin with the homobifunctional lysine‐lysine cross‐linking reagent dissuccinimidyl suberate (DSS) resulted in two cross‐links consistent with the known ubiquitin tertiary structure (K6‐K11 and K48‐K63). Because no protein or peptide chemistry steps are needed, other than the initial cross‐linking, this new top down approach appears well suited for high‐throughput experiments with multiple cross‐linkers and reaction conditions. Published in 2002 by John Wiley & Sons, Ltd.
Classification of green coffee beans by differences in protein composition obtained by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Procida Giuseppe , Campisi Barbara , Seraglia Roberta , Traldi Pietro 
Published: January 2003

AbstractIt is well known that proteins and peptides play an important role in the flavour of roasted coffee, but little is reported in the literature about their characterization. In view of the potential of matrix‐assisted laser desorption/ionization mass spectrometry in the analysis of proteins in complex mixtures, two varieties of coffee green beans, Arabicas and Robustas, were analyzed by this technique, in order to obtain fingerprints of their native proteins. Differences were observed between Arabicas and Robustas green beans, and cluster analysis allows differentiation of samples of the same variety from different plantations. Copyright © 2002 John Wiley & Sons, Ltd.
Quantitative analysis of clindamycin in human plasma by liquid chromatography/electrospray ionisation tandem mass spectrometry using d1‐N‐ethylclindamycin as internal standard
Authors: Rechberger Gerald N. , Fauler Günter , Windischhofer Werner , Köfeler Harald , Erwa Wolfgang , Leis Hans‐Jörg 
Published: January 2003

AbstractA new method for the quantitative analysis of clindamycin in human plasma by liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI‐MS/MS) is presented. Recently published methods possess a disadvantage because of their use of internal standards with extraction and ionisation properties different from those of clindamycin. To avoid these problems, d1‐N‐ethylclindamycin was synthesised for use as internal standard by N‐demethylation and subsequent d1‐N‐ethylation. Plasma sample preparation was done by an easy and rapid liquid–liquid extraction using ethyl acetate. The method was validated in the expected concentration range for a pharmacokinetic study. Calibration graphs were linear within the range 0.05–3.2 μg/mL plasma. Intra‐day precision was between 0.90% (2.8 μg/mL) and 3.25% (0.05 μg/mL), inter‐day variability was found to be between 1.33% (0.7 μg/mL) and 2.60% (0.05 μg/mL). Inter‐day accuracy showed deviations between 0.4% (0.05 μg/mL) and −4.8% (0.2 μg/mL). The method is simple and robust, and has been applied to the batch analysis of clindamycin during a pharmacokinetic study. Copyright © 2002 John Wiley & Sons, Ltd.
Performance of an ultra‐low elution‐volume 96‐well plate: drug discovery and development applications
Authors: Mallet Claude R. , Lu Ziling , Fisk Ray , Mazzeo Jeffrey R. , Neue Uwe D. 
Published: January 2003

AbstractRecently, sample preparation has been considered to be the major cause of bottlenecks during high‐throughput analysis. With the assistance of robotic liquid handlers and the 96‐well plate format, more samples can be prepared for subsequent liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis. Protein precipitation is still widely used despite potential loss of sensitivity or variable results due to ion suppression. The use of solid‐phase extraction (SPE) clearly gives superior results but may not be as cost effective as protein precipitation due to the labor and material costs associated with the process. Here, a novel 96‐well SPE plate is described that was designed to minimize the elution volume required for quantitative elution of analytes. The plate is packed with 2 mg of a high‐capacity SPE sorbent that allows loading of up to 750 μL of plasma, while the novel design permits elution with as little as 25 μL. Therefore, the plate offers up to a 15‐fold increase in sample concentration. The evaporation and reconstitution step that is typically required in SPE is avoided due to the concentrating ability of the plate. Examples of applications in drug discovery/development are shown and results are compared to protein precipitation. Excellent sensitivity and linearity are demonstrated. Copyright © 2002 John Wiley & Sons, Ltd.
Analysis of isomeric long‐chain hydroxy fatty acids by tandem mass spectrometry: application to the diagnosis of long‐chain 3‐hydroxyacyl CoA dehydrogenase deficiency
Authors: Johnson David W. , Trinh Minh‐Uyen 
Published: January 2003

AbstractAcetyl trimethylaminoethyl ester iodide derivatives have been used to selectively analyze isomeric long‐chain hydroxy fatty acids by electrospray ionization tandem mass spectrometry (ESI‐MS/MS). The binary derivatives of 2‐, 3‐, 12‐ and 16‐hydroxypalmitic acids afford remarkably different product ion spectra. Further discrimination between isomers is possible by acylating with pivaloyl chloride. 2‐ and ω‐Hydroxy long‐chain fatty acids form pivaloyl esters in quantitative yield whereas other secondary alcohols only partially react. Cotton‐based filter paper used for blood collection contains substantial amounts of esterified long‐chain hydroxy fatty acids. From the product ion spectra of the acetyl trimethylaminoethyl esters the hydroxydocosanoic and ‐tetracosanoic acids are >90% ω‐hydroxy. All remaining saturated and unsaturated hydroxy acids are >90% 2‐hydroxy acids. A method for the quantification of free 3‐hydroxypalmitic acid in plasma by ESI‐MS/MS for the diagnosis of long‐chain 3‐hydroxyacyl CoA dehydrogenase deficiency (LCHAD) is described. Median plasma concentrations of 0.43 μmol/L (control, n = 22) and 12.2 μmol/L (LCHAD, n = 3) were obtained from 5 μL plasma samples. Copyright © 2002 John Wiley & Sons, Ltd.
In situ capping design of a pyrite cinder pile in the St. Lawrence river for metal containment
Authors: Thibodeaux Louis J. 
Published: January 2003

AbstractA pile of pyrite cinders discharged from a former manufacturing facility rest upon the bottom of the St.
Lawrence River adjacent to Clark Island. In situ capping was the selected remedy to control both
the fine particle resuspension that produced a red mud cloud in the water, commonly formed on windy days, and the
soluble metals concentrations originating from the pyrite pile. Metal mass balances around the pile allowed
estimates of the pre‐capping release rates. Elevated concentrations above the pile were observed for eight
metals; these included iron, lead, mercury, selenium, arsenic, copper, cadmium, and zinc. After iron, the
highest concentration in the pyrite particles were cadmium and zinc present in the 1,000 mg/kg range. Mercury
was the lowest at the 10 mg/kg level in the pyrite solids. For iron the soluble release rate was estimated to
be 0.08 g/s, and the particle release was 0.8 to 1.2 g/s. A 30 cm cap consisting of particles 19 to 40 mm
in diameter is proposed for the site. Its placement covers a ten‐hectare area and is expected to isolate
the fine pyrite particles and prohibit their resuspension into the water column. Design estimates of steady state
flux reduction efficiencies range from a low of 99.21 percent for iron to a high of 99.96 percent for copper.
Breakthrough times to achieve these steady state flux reductions range from 100 to 3,800 years and metal porewater
concentrations at 5 cm below the cap surface are estimated to be reduced by 83 percent. Although soluble metals
will continue to be released from the pile zone, the flux of all the metals will be significantly reduced. ©
2002 Wiley Periodicals, Inc.
Combining Ion‐exchange (IX) technology and biological reduction for perchlorate removal
Authors: Batista Jacimaria R. , Gingras Tina M. , Vieira Adriano R. 
Published: January 2003

AbstractIon‐exchange (IX) resin is perhaps the most promising technology to remove the contaminant
perchlorate (ClO4−) from waters. However, ion exchange is only a separation
technology that transfers the perchlorate from waters to the waste solutions used to regenerate the resins. The
waste solutions contain high perchlorate concentrations, and treatment technologies for these regenerant
solutions are needed. In this article, we review the latest knowledge on perchlorate removal by
ion‐exchange resins; propose three systems that combine ion‐exchange resins (for
perchlorate removal) and biological reduction for treating the waste solutions resulting from resin
regeneration; and discuss the challenges and research needed to fully develop the proposed technology.
© 2002 Wiley Periodicals, Inc.
Choosing remediation and waste management options at hazardous and radioactive waste sites
Authors: Greenberg Michael , Burger Joanna , Powers Charles , Leschine Thomas , Lowrie Karen , Friedlander Barry , Faustman Elaine , Griffith William , Kosson David 
Published: January 2003

AbstractThis article discusses a process for finding insights that will allow federal agencies and environmental
professionals to more effectively manage contaminated sites. The process is built around what Etzioni
(1968) called mixed‐scanning, that is, perpetually doing both comprehensive and detailed
analyses and periodically re‐scanning for new circumstances that change the decision‐making
environment. The article offers a checklist of 127 items, which is one part of the multiple‐stage
scanning process. The checklist includes questions about technology; public, worker, and ecological
health; economic cost and benefits; social impacts; and legal issues. While developed for a DOE
high‐level radioactive waste application, the decision‐making framework and specific questions can
be used for other large‐scale remediation and management projects. © 2002 Wiley Periodicals,
Inc.
Field analyses of RDX and TCE in groundwater during a GCW pilot study
Authors: Elmore Andrew C. , Travaglin Lisa A. , Triplett Jennifer L. 
Published: January 2003

AbstractContaminant concentrations in groundwater are typically analyzed using traditional laboratory analytical
procedures approved by the Environmental Protection Agency (EPA) or state regulatory agencies. The use
of off‐site laboratories provides very high‐quality water quality data at a relatively high cost in
terms of time and money. Yet there are many instances when it is desirable to have water quality data measured in
the field. The field methods for measuring water quality typically cost much less than the corresponding
laboratory methods. However, the usability of the field data may be uncertain when the results are qualitatively
compared to duplicate laboratory results. Groundwater samples collected during a groundwater circulation well
pilot study were analyzed using field kits to measure concentrations of trichloroethylene (TCE) and the
explosive compound known as RDX. A subset of the samples was split for duplicate laboratory analysis. Linear
regression analysis and relative percent difference analysis were performed on the duplicate results to evaluate
the comparability of the field and laboratory data. The data analyses were also used to evaluate the concept that
the field kits were more accurate for specific concentration ranges, as well as the concept the field kit results
would improve as field personnel gained experience with the field analysis procedures. © 2002 Wiley
Periodicals, Inc.
In situ remediation of MTBE utilizing ozone
Authors: Dey Jeffrey C. , Rosenwinkel Paul , Wheeler Kevin 
Published: January 2003

AbstractThere has been a great deal of focus on methyl tertiary butyl ether (MTBE) over the past few years by
local, state, and federal government, industry, public stakeholders, the environmental services market, and
educational institutions. This focus is, in large part, the result of the widespread detection of MTBE in
groundwater and surface waters across the United States. The presence of MTBE in groundwater has been attributed
primarily to the release from underground storage tank (UST) systems at gasoline service stations.
MTBE's physical and chemical properties are different than other constituents of gasoline that have
traditionally been cause for concern [benzene, toluene, ethylbenzene, and xylenes (BTEX)]. This
difference in properties is why MTBE migrates differently in the subsurface environment and exhibits different
constraints relative to mitigation and remediation of MTBE once it has been released to subsurface soils and
groundwater.Resource Control Corporation (RCC) has accomplished the remediation of MTBE from subsurface soil and
groundwater at multiple sites using ozone. RCC has successfully applied ozone at several sites with different
lithologies, geochemistry, and concentrations of constituents of concern. This article presents results from
several projects utilizing in situ chemical oxidation with ozone. On these projects MTBE
concentrations in groundwater were reduced to remedial objectives usually sooner than anticipated. © 2002
Wiley Periodicals, Inc.
Directionally drilled horizontal wells offer cost savings and technical advantages over alternative soil and groundwater remediation systems
Authors: Fournier Louis B. 
Published: January 2003

AbstractDirectionally drilled horizontal wells offer the opportunity for significant cost savings and technical
advantages over alternative trenched well and vertical well soil and groundwater remediation systems in many cases.
The magnitude of the cost savings is a function of the remediation technology deployed and the values placed on the
reduction of site impacts, dramatic reduction in the time required to achieve site remediation goals and
requirements, the ability of horizontal well remediation to easily treat normally recalcitrant contaminants such as
MTBE, and the ability to drill under paved areas, operating plants, residential areas, landfills, lagoons,
waterways, ponds, basins, and other areas that are normally difficult or impossible to access with conventional
drilling or trenching methods. In addition to improvements in site access capabilities, horizontal wells have been
found capable of addressing contaminants that vertical wells do not readily treat, even with the same remediation
technology deployed, especially if air‐based remediation technologies are deployed. With biosparging, for
example, greater treatment capabilities of horizontal wells over vertical wells are attributed to greater oxygen
flux over a broader area, a larger treatment zone, and extremely prolonged residence of groundwater contaminants in
the aerobic treatment area, typically months or years. This article describes the use of directionally drilled
horizontal wells for application of a variety of treatment technologies and includes costs of various options with a
detailed comparison of biosparging options. © 2002 Wiley Periodicals, Inc.
Activity and Use Limitations applied to Risk‐Based Corrective Action—A checklist for efficacy
Authors: Sonnenfeld Paul 
Published: January 2003

AbstractActivity and Use Limitations (AULs) comprise both institutional controls and engineering controls.
AULs, when properly implemented, are valuable tools in the risk‐based corrective action arsenal.
However, the proponent of AULs must evaluate their life‐cycle costs and the short‐term and
long‐term effectiveness of the AULs to protect human health and the environment. This article describes
the various types of AULS and provides a checklist for evaluating the efficacy of the proposed AULs. ©
2002 Wiley Periodicals, Inc.
Incorporating ecology and ecological risk into long‐term stewardship on contaminated sites
Authors: Burger Joanna 
Published: January 2003

AbstractThe long‐term management of environmental contamination will be a major activity at many sites in the
foreseeable future. While human health issues often drive decisions about cleanup, restoration, and
long‐term stewardship, ecological considerations are also major driving forces and are of paramount
importance to the public. Incorporation of ecological considerations into decisions about environmental
protection, both short term and long term, requires (1) understanding public perceptions of ecological
values, including aesthetics and existence values, (2) understanding contamination issues within a
context of the structure and functioning of ecosystems, (3) developing bioindicators of ecological
health (including human), (4) developing indicators of ecosystem functioning, and
(5) developing and implementing a biomonitoring plan before, during, and after remediation so that
adverse effects can be ascertained before they become irreversible. Both remediation/restoration and
long‐term stewardship goals must be informed by public policy mandates that include public participation
and healthy human and ecological systems. This article examines these issues as they relate to
cost‐effective, long‐term protection of human and ecological health on contaminated lands. ©
2002 Wiley Periodicals, Inc.
Phytoremediation of industrial sludge using vegetation‐assisted dewatering
Authors: Qiu Xiujin , Loehr Raymond C. 
Published: January 2003

AbstractWith the emergence of risk‐based corrective action decisions, there is interest in the use of more
natural techniques that may be as protective as the traditional removal, landfill, or capping approaches for
impoundment closure. The use of phytoremediation is one of the more promising techniques. This article presents
the results of a three‐year field‐pilot phytoremediation study that involved the use of plants to
enhance sludge dewatering at an inactive natural gas‐cracking wastewater lagoon. The dewatering was
accompanied by contaminant reduction of benzene, toluene, xylene (BTX), and naphthalene concentrations
to below the cleanup goals. Meanwhile, the concentration reductions of three or more ring polynuclear aromatic
hydrocarbons (PAHs) varied between 30 percent and 60 percent, except for
dibenz[a,h]anthracene. The residual PAHs in the sludge are not leaching. Parallel laboratory studies
suggest a reduced PAH availability and mobility in the unsaturated zone sludge. © 2002 Wiley Periodicals,
Inc.