bluuebunny/crossref_metadata_2025 huggingface dataset:
A comprehensive approach for evaluating telemedicine-delivered multidisciplinary breast cancer meetings in southern Scotland
Authors: Kunkler I H , Fielding R G , Brebnei J , Prescott R , Maclean J R , Cairns J , Chetty U , Neades G , Walls A , Bowman A , Dixon J M , Gardner T , Smith M , Maccoubrey J , Lee A J , Swann S , Macnab M , Wilson J , Nawroz I
Published: July 2005

Multidisciplinary team (MDT) meetings for decisions on cancer management are a cornerstone of UK cancer policy. We have proposed a comprehensive methodology to assess the clinical and economic effectiveness of telemedicine in this setting, which is being tested in a randomized breast cancer trial. Pre- and post-telemedicine assessment includes attitudes to and expectations of telemedicine, based on semistructured interviews. The communication content of videotapes of the MDT meeting is being scored using Borgatta's revised Interaction Process Analysis System. The technical performance of the telemedicine equipment is reported on a standardized pro forma. A short questionnaire captures key elements of professional satisfaction for each patient discussion (consensus on future management, confidence in and sharing of decision), added value of linkage, group atmosphere, overall conduct of the meeting and compliance with SIGN guidelines. A cost-minimization analysis will be used for economic assessment.
Health information seeking and its effect on the doctor-patient digital divide
Authors: Malone M , Mathes L , Dooley J , While A E
Published: July 2005

A survey of 224 individuals using SureStart services (for young families) within an inner-London area was complemented by qualitative data from five focus groups of parents and general practitioners in the same area. Descriptive and multivariate statistics were used to identify and describe discrete geographical districts with differing patterns of health information seeking. A geographically defined group of ‘information hungry’/‘online’ health seekers was identified. This group contrasted with those acquiring information through ‘assimilation’ (‘offline’ information seekers). Qualitative data revealed the processes underpinning these characteristics and professional attitudes towards the Internet as a source of health information.
Telemedicine in a child and adolescent mental health service: Participants’ acceptance and utilization
Authors: Grealish Annmarie , Hunter Andrew , Glaze Robin , Potter Louise
Published: July 2005

Videoconferencing equipment was set up in Scotland in response to the increased pressure faced by the child and adolescent mental health services (CAMHS), and the need for specialist services to be accessible to, and harmonize with, ‘mainstream’ health services. Three sites were linked to the inpatient service in Edinburgh. Data were collected via questionnaires and diary logs. During a 24–month study, a total of 65 adolescents were admitted for inpatient care, of whom only five had their cases reviewed and monitored in a total of 20 teleconsultations. Adolescents and their carers involved in the study expressed great satisfaction with telemedicine and were keen to use it. Clinicians were resistant to telemedicine, with consequently low levels of utilization. Our results suggest that managers may be unwilling to reallocate funding away from staffing, even where these costs are small and represent considerable improvements in the process of care for patients. Widespread integration of telemedicine to CAMHS is likely to be hard to achieve.
Role of telecardiology in the assessment of angina in patients with recent acute coronary syndrome
Authors: Chiantera A , Scalvini S , Pulignano G , Pugliese M , De Lio L , Mazza A , Fera M S , Bussolotti L , Bartolini S , Guerrieri L , Caroselli A , Giovannini E
Published: July 2005

We compared two models of assistance (telecardiology versus usual care) for patients discharged after acute coronary syndrome (ACS), in the assessment of angina. Two hundred patients were randomized into two groups at discharge for ACS: Group A to telecardiology and Group B to usual care. Early hospital readmission (in the first month) occurred in 16 patients (seven in Group A and nine in Group B). Six of Group A were readmitted for a cardiac cause (non-cardiac in one). Angina was the only cardiac cause. Five of the Group B patients were readmitted for a cardiac cause (non-cardiac in four). The results of the present study emphasize that patients with ACS suffer from a definite rate of cardiac symptoms within the first month (63%). Angina occurs more frequently within the first two weeks (68% of cases). Telecardiology slightly reduces hospital readmissions (telecardiology 44% versus usual care 56%), but better identifies true angina.
From a Meccano set to nano meccano
Authors: Stoddart J. Fraser
Published: July 2005

The hurly-burly life of a scientific nomad is traced through thick and thin from the Athens of the North to the City of Angels with brief and not so brief interludes on the edge of the Canadian Shield, in the Socialist Republic of South Yorkshire, on the Plains of Cheshire beside the Wirral, and in the Midlands in the heartland of Albion.
Total synthesis of zincophorin
Authors: Cossy Janine , Meyer Christophe , Defosseux Magali , Blanchard Nicolas
Published: July 2005

A total synthesis of the naturally occurring ionophore zincophorin has been realized. The key steps are an intramolecular oxymercuration of a cyclopropanemethanol for the elaboration of the tetrahydropyran ring and a Carroll–Claisen rearrangement to control the configuration of the double bond at C20–C21 as well as the stereogenic center at C21.
Syntheses of antiangiogenic or cytotoxic natural products: Fumagillin and bengacarboline
Authors: Bedel O. , Haudrechy A. , Pouilhès A. , Langlois Y.
Published: July 2005

Syntheses of fumagillol, a precursor of antiangiogenic sesquiterpene fumagillin, and of cytotoxic marine alkaloid bengacarboline are described.
Total synthesis and structural elucidation of natural products: (–)-Delactonmycin, (+)-plumerinine, and (–)-parvistemoamide
Authors: Pilli Ronaldo A. , Corrêa Ivan R. , Maldaner Adriano O. , Rosso Giovanni B.
Published: July 2005

Synthetic studies that established the relative configuration of (–)-delactonmycin, a polyketide with inhibitory activity against HIV-1 Rev protein, and our efforts toward the structural elucidation of the alkaloids (+)-plumerinine, isolated from P. rubra, and (–)-parvistemoamide, isolated from S. parviflora, are discussed.
Carbohydrates as versatile platforms in the construction of small compound libraries
Authors: Timmer Mattie S. M. , Verhelst Steven H. L. , Grotenbreg Gijsbert M. , Overhand Mark , Overkleeft Herman S.
Published: July 2005

This paper presents our recent results concerning the use of carbohydrates as cheap, chiral, and enantiopure starting materials in the construction of a variety of densely functionalized molecules. The compatibility of ring-closing metathesis with standard carbohydrate chemistry is demonstrated in the synthesis of new stereoisomers of deoxystreptamine and neamine–important building blocks for the generation of synthetic aminoglycosides with potential antibacterial activity. Ring-closing metathesis is also a key step in the rapid synthesis of new indolizidines and quinolizidines, and in a new solid-phase assisted carbohydrate-based combinatorial scaffold strategy. Further, some of our latest results in the conformational analysis of sugar amino acid-based peptide mimetics and in the development of a novel Ugi-type three-component reaction of sugar-derived azido-aldehydes are discussed.
Application of the carbene cyclization-cycloaddition cascade in total synthesis
Authors: Chiu Pauline
Published: July 2005

The title reaction is a key transformation that has been applied to the synthetic studies of the antitumor and antifungal compounds, the pseudolaric acids.
General and practical approach to the syntheses of linear homoallylic alcohols
Authors: Cheng Hin-Soon , Loh Teck-Peng
Published: July 2005

We have demonstrated that metal-mediated allylation of aldehydes can afford γ-homoallylic alcohols or α-linear homoallylic alcohols by judicious choice of the solvents. A new mechanism has been proposed to account for this new α-selective metal-mediated allylation reaction. On the other hand, the metal-mediated prenylation under the same conditions to obtain α-prenyl alcohols was unsuccessful. Detailed mechanistic studies have resulted in the discovery of a new method to obtain compounds with diverse structures via an oxonium-ene cyclization. Suppressing the oxonium-ene reaction during the reaction has resulted in the formation of α-prenyl alcohols. A highly enantioselective process to obtain α-prenyl product in high optical purity has also been accomplished.
Ring-closing metathesis: A facile construct for alkaloid synthesis
Authors: Martin Stephen F.
Published: July 2005

Ring-closing metathesis has been found to be a highly effective reaction for the synthesis of functionalized, bridged nitrogen heterocycles. The utility of the process has been established in several case studies, including a facile synthesis of the tropane ring system and efficient, enantioselective syntheses of the natural products (–)-peduncularine and (+)-anatoxin-a.
Masked o-benzoquinone strategy in organic synthesis: Short and efficient construction of cis-decalins and linear triquinanes from 2-methoxyphenols
Authors: Liao Chun-Chen
Published: July 2005

The inter- and intramolecular Diels–Alder reactions of masked o-benzoquinones generated in situ from the oxidation of easily accessible 2-methoxyphenols with diacetoxyiodobenzene or bis(trifluoroacetoxy)iodobenzene provided cycloadducts in excellent regio- and stereoselectivity and good yields. A general approach to the synthesis of highly substituted cis-decalins and triquinanes with complete stereocontrol from the cycloadducts has been developed. The applicability of our methodology is demonstrated by the total syntheses of several natural products.
Diastereoselective alkylation of cyclo-β-dipeptides en route to enantiopure β-amino acids
Authors: Juaristi Eusebio , Aviña Judit
Published: July 2005

The cyclization of various β-amino acids with PhP(O)Cl2 affords cyclo-β-dipeptides, whose boat conformation is probably responsible for the high diastereoselectivity observed in the alkylation reactions of their lithium enolate derivatives.
Chiral designer phase-transfer catalysts for practical asymmetric synthesis
Authors: Maruoka Keiji
Published: July 2005

A series of C
2-symmetric, spiro-type chiral quaternary ammonium bromides have been designed as new, purely synthetic chiral phase-transfer catalysts, and readily prepared from commercially available optically pure (R)- or (S)-1,1'-bi-2-naphthol as a basic chiral unit. The structures of the assembled N-spiro chiral quaternary ammonium bromides were unequivocally determined by single-crystal X-ray diffraction analysis. The reactivity and selectivity of these chiral ammonium bromides as chiral phase-transfer catalysts have been evaluated in the asymmetric alkylation of N-(diphenylmethylene)glycine tert-butyl ester under mild liquid–liquid phase-transfer conditions, and the optimization of the reaction variables (solvent, base, and temperature) has also been conducted. Furthermore, the scope and limitations of other asymmetric transformations have been thoroughly investigated with a variety of substrates, in which the advantage of the unique N-spiro structure of our chiral phase-transfer catalysts and dramatic effect of the steric as well as the electronic properties of the aromatic substituents on the 3,3'-position of one binaphthyl moiety have been particularly emphasized.
Computer-Controlled Densitometer for the Analysis of Photographically Recorded Optical Emission Spectra
Authors: Hareland Willard A. , Grant Stephen E. , Ward Steven P. , Anderson David R.
Published: July 2005

A computer-controlled densitometer for data acquisition and high speed analysis of photographically recorded optical emission spectra has been developed. The instrument scans and digitizes spectra and stores the data sequentially in computer memory. A high-resolution linear measurement transducer mounted on a Jarrell-Ash densitometer monitors the plate position as the spectrum is scanned. The transducer measurement is accurate to within 0.001% over a range of about 340 mm on a glass photoplate. Computer algorithms for locating and identifying peaks and for calculating the wavelengths of spectral lines from their positions in the spectrum are described. With the use of a calibration curve based on the measured positions of three known spectral lines, the wavelength of any spectral line can be determined to within 0.005 nm, and the transmittance of a peak in the recorded spectrum can be measured to within 1%. The wavelengths and transmittances of all detectable spectral lines in the digitized emission spectrum are determined in less than two minutes.
Myotoxin a-Phospholipid Interactions, an Attempt by Intrinsic Fluorescence to Define a Possible Mode of Action for the Toxin on Membranes
Authors: Dufourco Jean , Dousseau Francoise , Faucon Jean-FrançOis , Tu Anthony T.
Published: July 2005

Intrinsic fluorescence of myotoxin a from Crotalus viridis viridis has been proved to be due to tryptophan residues, and this knowledge allows one to detect, for the first time, an interaction of the toxin with phospholipids. The formation of lipid-protein species is followed by a blue shift of about 8 nm and a quenching of up to 50% of the emission of tryptophans. These changes could result from the positioning of Trp 32,34 residues at the lipid interface and/or a local conformational change of the toxin. In the μM range, complexes are formed only with charged lipids; charge complementarity of two partners is needed regardless of the physical state of the lipids. The binding is electrostatic, and the affinity of myotoxin a decreases in parallel with the net charge of the phospholipid interface and/or that of the toxin. Similarly, calcium-ion addition, pH changes, and an increase in ionic strength can dissociate the complexes. Their stability increases in the following sequence: phosphatidylinositol < phosphatidylserine < phosphatidylglycerol < phosphatidic acid < cardiolipin. It is proposed that the toxin lies at the interface, without penetrating the membrane. On binding, the toxin does not severely change the structure of lipid vesicles nor their permeability; however, significant changes in the lipid chain order are detected with synthetic lipids, both in their gel and fluid phases. The possible consequences of the existence of myotoxin a-charged phospholipid complexes are discussed and are compared to the behavior of other related basic toxins of snake venom acting on membrane.
Closure Effects on Infrared Spectral Library Search Performance
Authors: Harrington P. B. , Isenhour T. L.
Published: July 2005

Closure is caused by normalization of a data set, and it affects any multivariate analytical method applied to that data set. Two common methods of normalizing infrared spectra (IR), to unit maximum absorbance and to unit vector length, are evaluated by measurement of library search performance. Search performance is evaluated, by the use of the Quantitative Reliability Metric (QRM), as a function of noise frequency and noise level.
Investigation of the Effect of Gamma-Radiation on High-Density Polyethylene by Solid-State Magic-Angle 13C NMR Spectroscopy
Authors: Cholli Ashok L. , Ritchey William M. , Koenig Jack L.
Published: July 2005

The structural and morphological changes occurring in high-density polyethylene when exposed to gamma-radiation have been investigated by high-resolution solid state 13C NMR. NMR measurements are used to study the effect of gamma-radiation on crystalline and amorphous components. In addition, resonance peaks due to direct cross-links have been detected. The changes in main chain unsaturation are also studied.
FT-IR Spectra of Soil Constituents: Fulvic Acid and Fulvic Acid Complex with Ferric Ions
Authors: Byler D. Michael , Gerasimowicz Walter V. , Susi Heino , Schnitzer Morris
Published: July 2005

FT-IR spectra and corresponding second-derivative spectra, as well as pertinent difference spectra, of fulvic acid and of fulvic acid complexed with ferric ions have been obtained. The data reveal that the major functional groups present in the fulvic acid studied are carboxyl groupings and CH2 groupings of hydrocarbon chains. The presence of ferric ions results in increased ionization of the COOH groups to form COO− ions, as well as a change of the characteristic COO− stretching frequencies of the carboxylate ions. The data thus indicate that ferric ions in soils interact with carboxylate ions of fulvic acids. The second-derivative spectra permit the identification of certain alkyl and aromatic hydrocarbon vibrational modes which cannot be observed in the original FT-IR spectra.
A Method for Quantitative Multielemental Analysis of Specimens of Low-Z Matrix by Photon-Excited X-Ray Fluorescence
Authors: Yap C. T. , Tang S.M. , Wongnawa S.
Published: July 2005

A method is described for obtaining the concentrations of trace elements in samples of low-Z matrix by measuring the intensities and transmittances of such samples of intermediate thickness in pellet form. This method has been applied to the determination of the minor and trace elements of Certified Reference Material IAEA/V-10 hay powder, and the results are in good agreement with quoted values.
Spatial Diagnostics in Inhomogeneous Flames with a Copper Vapor Laser System: Absorption, Two-Wavelength Fluorescence, and Two-Wavelength Ionization
Authors: Rutledge M. J. , Mawn M. , Smith B. , Winefordner J. D.
Published: July 2005

Two-wavelength laser-excited fluorescence and laser-enhanced ionization are investigated for use with spatial profiling applications. A recently introduced absorption technique (which involves measuring the differential absorption of a probe beam with a pump beam on and off) is also investigated for use with spatial profiling applications and determination of absolute number densities. A high-repetition-rate, high-average-power copper vapor laser with a computer-controlled data acquisition and beam scanning system was used for speed, repeatability, and ease of data collection. Design, construction, and associated operating parameters are reviewed. Preliminary results are presented from an application of these techniques to the measurement of sub-part-per-million concentrations of sodium in a separated acetylene-oxygen-nitrogen flame.
A Simplex Optimized Inductively Coupled Plasma Spectrometer with Minimization of Interferences
Authors: Kalivas John H.
Published: July 2005

Several figures of merit are considered as criteria to optimize an ICP atomic emission spectrometer for quantification of multielement systems. A criterion is proposed and evaluated that will establish optimum analysis conditions with minimization of spectral interferences. The optimization scheme makes use of the variable step-size simplex technique.
Laser Optogalvanic Study of a Helium Hollow Cathode Discharge
Authors: Fleitz P. A. , Seliskar C. J. , Fannin H. B.
Published: July 2005

A helium hollow cathode lamp operated under flow conditions provides a simple optogalvanic source with typically large voltage transients. An analysis of the transients for the two transitions at 3889 Å and 5015 Å using a simple two-level kinetic model suggests that the upper states of these transitions (33 P and 31 P, respectively) are quite different in their sensitivity to lamp pressure. Reasons for the variations observed in the transients with varying pressure and applied voltage are discussed.
FT-IR Micro-Spectroscopic Studies of Several Charge-Transfer Organic Electrical Conductors
Authors: Ferraro John R. , Wang Hau H. , Ryan John , Williams Jack M.
Published: July 2005

A series of infrared reflectance measurements using FT-IR Micro methods were conducted on bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or “ET”) and bis(propylenedithio)tetrathiafulvalene (BPDT or “PT”) salts of the type (ET)2 X, where X = I3, AuCl2−, AuBr2−, AuI2−, I2Br−, IBr2, ICl2, ReO4−, ClO4−, and [Formula: see text]; and (PT)2 X, where X = I3−, IBr2−, I2Br−, and ICl2−. The technique is useful for characterizing, at room temperature, differences between β-, β′- and α′-type structures vs. α-structures. The β-, β′-, and α′-type structures show a vibrational feature at ∼1280 cm−1 which has been assigned as the -C-C-H bending vibration and is absent in the spectrum of the α-type salts. This vibration shifts toward higher frequency in going from the PT to the ET salts, and the results indicate stronger hydrogen bonding and harder lattices in the ET salts as opposed to the PT salts. This frequency shift also appears to be a function of the electronegativity of the halogen in the anion moiety of the charge-transfer salt.
Detection of Explosives Using Laser Desorption in Ion Mobility Spectrometry/Mass Spectrometry
Authors: Huang Shi Duo , Kolaitis Leonidas , Lubman David M.
Published: July 2005

Laser desorption is used to volatilize explosive materials for analysis by ion mobility/mass spectrometry measurements. The laser desorption is performed at relatively low power (< 107 W/cm2) so that mainly neutrals are produced, which are subsequently ionized by 63Ni-β-source induced ion-molecule reactions at atmospheric pressure. Atmospheric pressure ionization, together with the soft vaporization method, produces relatively simple spectra of the explosives investigated, yielding ions that are very characteristic of each molecule for identification. The technique has great potential for high sensitivity based upon the combination of complete laser vaporization of the sample and the API method, which is an extremely efficient form of ionization for these molecules with high electron affinities.
The Use of Fourier Deconvolution in Infrared Spectroscopy. Part I: Studies with Synthetic Single-Peak Systems
Authors: James D. I. , Maddams W. F. , Tooke P. B.
Published: July 2005

Studies with synthetic single-peak systems have provided information on a range of factors capable of limiting the utility of Fourier deconvolution for peak finding in vibrational spectra. The merits of six apodization functions for controlling Gibbs oscillations resulting from truncation and background effects have been determined. The triangularsinc and triangular-squared functions are the most effective, and the Gaussian function is the least satisfactory. The presence of asymmetry and a degree of Gaussian character in the band shape should not prove a serious limitation for most qualitative and quantitative applications. The peak heights following deconvolution are linear functions of the resolution enhancement factor, K, the constant of proportionality being determined by the particular apodization function employed. By contrast, the areas of deconvoluted bands are sensibly independent of the apodization function. This factor opens the way to quantitative studies on deconvoluted band systems.
Are Group Frequencies Obsolete?
Authors: Smith A. Lee
Published: July 2005

In spite of the diminishing number of publications on the subject, group frequencies remain an important research tool for infrared spectroscopists. The capabilities of FT-IR present us with opportunities for discovering useful new correlations. High-quality conventional spectra, vapor spectra, and matrix isolation spectra are easy to obtain. Large libraries of FT-IR spectra are being generated and made available in digital form for fast library searching. Computerized spectrum interpretation is becoming a reality. All these applications, for best utility, require wavelength accuracy of ±l/cm, and this accuracy is easily obtainable from FT-IR spectrometers. Unfortunately, the need for sample integrity and careful sample handling is often unappreciated and may be the fatal flaw that prevents us from realizing the full potential of the infrared method. Careful sample selection, the use of good sample handling techniques, and evaluation of the resulting spectrum by a knowledgeable spectroscopist can minimize problems. Several examples of the uses of group frequencies accurate to ±l/cm in organosilicon chemistry are given.
The Reverse Mirage Effect: Catching the Thermal Wave at the Solid/Liquid Interface
Authors: Smith Matthew J. , Palmer Richard A.
Published: July 2005

Detection of species at the solid/liquid interface using infrared spectroscopy is severely limited by the opacity of most liquids to the infrared beam. In this work we use a variant of the photothermal beam deflection (“mirage effect”) method to avoid this problem. With this variant of the method (the “reverse mirage effect”), the IR beam passes through a transparent solid first, and then is absorbed by a liquid medium or by chromophoric species at the solid/liquid interface. The probe laser beam grazes the nonilluminated (back) surface of the solid and is deflected by the thermal gradient in the liquid. Results are presented that were obtained with the use of the reverse mirage technique with single-crystal silicon as the transparent solid and the use of pure acetonitrile as the absorbing sample and beam deflection medium. Studies of the position of the laser probe beam center with respect to the Si/CH3CN interface reveal interesting qualities about photothermal detection within the absorbing medium. The resulting spectra are analyzed in terms of the Rosencwaig-Gersho model.
Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part II
Authors: Coleman W. M. , Gordon Bert M.
Published: July 2005

Matrix-isolated (MI) Fourier transform infrared spectra have been collected on a series of aliphatic ketones. The values for the carbonyl absorptions maxima are intermediate between vapor-phase (VP) and solid-state solution (SS) phases. The data reveal a stereochemical influence on the position of the ketone carbonyl absorption when the carbons that are in the alpha position with respect to the carbonyl group contain alkyl snbstituents vs. protons. Steric bulk causes the frequency of the absorption to decrease. The position of the ketone carbonyl absorption was also shown to decrease as the carbonyl group migrated toward the center of a long straight-chain hydrocarbon backbone. Stereochemical influences due to ring strain were also documented. Unsaturation, located in the alpha position with respect to the carbonyl, was shown to reduce the absorption frequency. The trends found in this MI study are comparable to those previously documented from VP and SS studies. In two cases wherein very bulky substituents were located in the alpha position with respect to the carbonyl, a splitting of the carbonyl absorption was observed. Studies are underway to test for a general trend in and to uncover an explanation for this phenomenon.
In Situ Studies of Coatings on Metal Wires by FT-IR External Reflectance Spectroscopy
Authors: Xue Gi , Liu Shi-Ying , Jin Yi , Jiang Shan-Geng
Published: July 2005

Diffuse reflectance FT-IR spectroscopy was originally developed for particulate samples dispersed in KBr powders. Now, by using ellipsoid mirrors for scattered light collection, we have taken advantage of the collection efficiency of diffuse reflectance optics and have extended their use to an in situ study of coatings on metal wires and of the broken surface of a reinforcement wire as well. The result is that spectra of coatings on wire show good overall agreement with external reflection spectra of thin films. The technique we have developed has an advantage over infrared attenuated total reflection (ATR), in that there is no optical contact problem between the wire sample and ATR crystal.
Use of a Prior-Oxidation Procedure for the Determination of Iodine by Inductively Coupled Plasma-Atomic Emission Spectrometry
Authors: Nakahara Taketoshi , Wasa Tamotsu
Published: July 2005

A simple prior-oxidation procedure is described for the determination of low concentrations of iodine by inductively coupled plasma-atomic emission spectrometry (ICP-AES) in the ultraviolet and vacuum ultraviolet (VUV) regions of the spectrum. For measuring spectral lines in the VUV region, the monochromator and the enclosed external optical path between the ICP source and the entrance slit of the monochromator have both been purged with nitrogen to minimize oxygen absorption below 190 nm. Iodine atomic emission lines at 206.16 and 183.04 nm have been selected as the analytical lines. The ICP-AES intensity is enhanced by a factor of up to 50 by prior oxidation of the iodide to elemental iodine using several oxidizing additives, presumably because of increased sample-transport efficiency between the nebulizer and the plasma. The best attainable detection limits (3-σ criterion) for iodine at 183.04 and 206.16 nm were 2.00 and 13.9 ng/mL, respectively, in the presence of 3.5-M perchloric acid or 0.2-M hydrogen peroxide, while the corresponding detection limits were 0.088 and 0.56 μ/mL in the absence of an oxidizing additive. The typical analytical working graphs obtained under the optimized operating conditions were rectilinear over approximately five orders of magnitude in concentration.
Molecular Orbital Study of the Losses of CO2 and H2O in the Fast Atom Bombardment Mass Spectra of Polyether Antibiotics
Authors: Siegel Marshall M. , Colthup Norman B.
Published: July 2005

In an earlier fast atom bombardment mass spectroscopy study of polyether antibiotics containing a β-hemiketal carboxylic acid group, the base peak was found to originate from the unusual fragmentation process where both CO2 and H2O were lost from the metal-adduct molecular ion. In this paper, the details of this fragmentation process are studied by ab initio molecular orbital calculations, which indicate that the concerted loss of both CO2 and H2O is much favored over sequential losses of CO2 and H2O.
Resonance Raman Spectroscopic and Emission Studies on Nickel, Palladium, and Platinum Tetraphenylporphyrins in Noncoordinating and Coordinating Solvents
Authors: Seo Jung-Chul , Chung Young-Boong , Kim Dongho
Published: July 2005

Luminescence spectra and Resonance Raman (RR) spectra are reported for nickel, palladium, and platinum complexes of tetraphenylporphyrin (TPP) in methylene chloride and piperidine. For NiTPP the RR frequencies in the range of 900 to 1700 cm−1 are reported for 4-coordinate low-spin (methylene chloride) and 6-coordinate high-spin (piperidine) forms. The core size expansion for the high-spin complex results in large decreases in several high-frequency porphyrin skeletal modes. For PdTPP and PtTPP the luminescence spectra and RR frequencies are reported for methylene chloride and in methylene chloride/piperidine mixtures. It has been reported previously that PdTPP and PtTPP do not coordinate significantly with pyridine because of a large ligand-field splitting. However, in a strongly ligating solvent like piperidine, PdTPP and PtTPP apparently form 5-coordinate low-spin complexes, as judged by spinorbit coupling parameters and luminescence spectra. The RR frequencies remain essentially the same in methylene chloride and piperidine, because for Pd and Pt the spin states are low-spin in both solvents.
The Multiplex Disadvantage and Excess Low-Frequency Noise
Authors: Voigtman Edward , Winefordner James D.
Published: July 2005

Analysis of the performance of a Fourier transform spectrometer with respect to source shot and flicker noises is presented. It was found that source shot noise uniformly distributes throughout the baseline, whereas source flicker noise remains localized about the generating spectral region(s).
Energy Transfer and Ionization Processes in a Reduced-Pressure Argon ICP
Authors: Fannin H. B. , Seliskar C. J.
Published: July 2005

The spectral characteristics of an argon/helium ICP operated at reduced-pressure are presented. The state population distributions deduced from quantitative intensity measurements for plasma neutral and cationic species suggest that the argon/helium plasma is essentially an argon plasma with respect to energy stratification. Comparisons are made with recently reported results for an atmospheric-pressure argon/helium ICP.
Near-Infrared Spectrum Qualification via Mahalanobis Distance Determination
Authors: Whitfield Richard G. , Gerger Mark E. , Sharp Robert L.
Published: July 2005

The use of near-infrared reflectance analysis (NIRA) for the quantitation of components of complex mixtures is well established. The lack of qualitative feedback in this approach is a major drawback. In view of this, it is believed that qualitative evaluation of the sample spectrum is also necessary for routine application of the NIRA technique. A method for qualifying a spectrum for application of a quantitative equation is described. The method involves generation of a quantitative equation, followed by the development of a qualitative equation based on the Mahalanobis distance algorithm, which is used to determine if the spectrum is suitable for analysis. This approach is demonstrated for the determination of lincomycin in an agricultural premix. The determination of proper control limits on the Mahalanobis distance is discussed. The improvement in precision obtained with the use of spectral selection is reviewed.
Vibrational Circular Dichroism Measurement in the Frequency Range of 800 to 650 cm−1
Authors: Devlin F. , Stephens P. J.
Published: July 2005

The development of dispersive instrumentation for the measurement of vibrational circular dichroism (VCD) with a lower frequency limit of ∼650 cm−1 is reported. VCD spectra of 3-methylcyclohexanone, α-pinene, and 3-bromocamphor in the frequency range of 800 to 650 cm−1 are presented to illustrate instrumental performance. The spectra obtained are superior to earlier spectra obtained with the use of a Fourier transform spectrometer.
Imprecision in Circle Cell FT-IR Analysis of Aqueous Solutions
Authors: Braue Ernest H. , Pannella Michael G.
Published: July 2005

Factors which produce imprecision during quantitative analysis of aqueous solutions using the CIRCLE CELL® have been investigated. The FT-IR spectra of aqueous acetone solutions have been recorded over the concentration range 0.01 to 90% (w/w). Using a micro-boat sampling cell, fixed in position within the CIRCLE CELL® optical bench, we have found that the uncertainty in repositioning the micro-boat sampling cell, within the CIRCLE CELL® optical bench, was the most important factor causing imprecision during quantitative analysis of aqueous solutions, especially as the detection limit was approached. At low concentrations, quantification using peak height values was more precise than that using integrated peak area values. Integrated peak area values, however, gave a more linear response and better correlation with Beer's law over a large concentration range. The reliable detection limit was found to be 0.05% (w/w).
Rapid, On-Line Preconcentration, Matrix Normalization, and Signal Enhancement for Flame Atomic Absorption via Tubular Donnan Dialysis
Authors: Koropchak John A. , Dabek-Zlotorzynska Ewa
Published: July 2005

The application of tubular ion-exchange membranes for on-line use with flame atomic absorption (FAA) was investigated. Signal enhancement factors as high as 22 were observed within five minutes for a variety of cations. Enhancements improved with lower pH receiver solutions, increased tubing length, and increased temperature. Optimum receiver flow rates were a compromise between optima for independent Donnan dialysis or FAA experiments. Low anion interferences were observed for phosphate-to-calcium mole ratios up to 80.
Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part IV
Authors: Coleman W. M. , Gordon Bert M.
Published: July 2005

Matrix-isolated (MI) Fourier transform infrared spectra (FT-IR) have been collected on a series of aldehydes and acids. The values for the carbonyl absorption are intermediate between the higher values for vapor-phase (VP) and lower values for solid-state (SS) phases. Substituent effects on aromatic rings induce shifts in carbonyl absorptions in the same manner as found in VP and SS studies. The magnitude of the shifts is approximately the same for all three phases. The spectra reveal a splitting or broadening of the carbonyl absorption for both aldehydes and acids. The size of the molecule affects the degree of band broadening. In certain cases discrete conformers appear to have been isolated in the matrix.
Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part III
Authors: Coleman W. M. , Gordon Bert M.
Published: July 2005

Matrix-isolated (MI) Fourier transform infrared spectra (FT-IR) have been collected on a series of esters and ketones. The values for the carbonyl absorption are intermediate between the values for vapor-phase (VP) and solid-state (SS) phases. The spectra reveal a splitting or broadening of the carbonyl absorption in the majority of cases for both compound types. The splitting, on the order of 5 to 10 cm−1, does not appear to be a function of concentration at ≤20 ng on the cryogenic disk. The splitting is also not unequivocally due to steric hindrance about the carbonyl group. Compounds with liner as well as branched substituents display spectra having split carbonyl absorptions. Isolation of molecules within multiple types of matrix sites is advanced as the predominant cause of the splitting phenomenon. Implications and consequences of the observed splitting are discussed.
A Raman Spectroscopy Cell for Aqueous Solutions to 500°C and 34.5 MPa
Authors: Spohn P. D. , Brill T. B.
Published: July 2005

The design of a Raman spectroscopy cell capable of maintaining aqueous solutions at temperatures up to 500°C and pressures up to 34.5 MPa (5000 psi) is described. The apparatus is illustrated with the chemical interactions that take place in aqueous Ca(NO3)2 and Zn(NO3)2 under these conditions.
Identification of the Isomers of Carvomenthol by an Infrared Study of the OH-Stretching Vibration
Authors: Lutz E. T. G. , Van Der Schaaf P. A. , Van Der Maas J. H.
Published: July 2005

A natural mixture of carvomenthols has been separated by HPLC into its four possible isomers. The infrared spectra of the OH-stretching vibration have been recorded for each of these components as a solution in CCl4 and CS2. Identification of the isomers followed, on the basis of these spectral data and those of some reference compounds. Evidence is found for a ring-conversion equilibrium in iso-carvomenthol at ambient temperature.
Characterization of the Adsorption of Poly(Acrylamide), Poly(4-methoxystyrene), and Poly(Acrylic Acid) on Aluminum Oxide by Inelastic Electron Tunneling Spectroscopy
Authors: Colletti Ronald F. , Gold Harvey S. , Dybowski Cecil
Published: July 2005

The adsorptions of polystyrene, poly(methoxystyrene), poly(acrylamide), and poly(acrylic acid) on aluminum oxide are investigated with inelastic electron tunneling spectroscopy. Comparison with infrared data for thin polymer films of the polymer samples gives insight into the adsorbed polymer configuration. Data indicate that poly(styrene) is weakly physisorbed to aluminum oxide, while poly(methoxystyrene), poly(acrylamide), and poly(acrylic acid) react to form strong bonds with the oxide surface. On the basis of this data, adsorption mechanisms are suggested for each of the polymers. Poly(acrylamide) adsorbs via a protonation of the amine group by the surface hydroxyl groups. Poly(4-methoxystyrene) forms a phenolate ion and can react further with the aluminum surface centers. Poly(acrylic acid) adsorbs to the oxide surface in a manner analogous to that of small organic acids such as the carboxylate ion.
A UV-VIS Spectrophotometer for Absorbance Measurements of Weakly Transparent Light Scattering Samples
Authors: Soulignac J. C. , Lamotte M.
Published: July 2005

Absorption measurements by transmission through weakly transparent media present some difficulties with conventional commercial spectrophotometers when both good sensitivity and high resolution are required. We describe a home-made computerized spectrophotometer which has been designed for absorption measurements through poorly transparent highly light scattering solutions. Emphasis is given to the difficulties inherent in this type of measurement. Examples are presented to illustrate the effects of the sample thickness and of the fluorescence, which can substantially affect the measured absorbance.
Application of Micro-FT-IR Spectroscopy to Individual Hydrocarbon Fluid Inclusion Analysis
Authors: Barres O. , Burneau A. , Dubessy J. , Pagel M.
Published: July 2005

Infrared spectra of fluid inclusions are obtained with a Fourier transform infrared miscrospectrometer. The experimental conditions and the analytical use are discussed. Interferograms are recorded in the transmission mode. The quality of spectra is good for fluid inclusions with diameters larger than 30 μm, the spectral resolution being 4 cm−1 and the recording time 200 s. Interferograms made of inclusions with diameters of less than 20 μm are reached in the same amount of time, but with worse spectral resolution. Infrared spectra are usually only suitable above 2000 cm−1, because of the absorption of most of the inclusion-bearing host minerals, the thickness of which should never exceed 1 mm. This fact further limits their interpretation, as the inclusion composition is complex. However, complementary information can be obtained in the 4600–4000-cm−1 range for hydrocarbon inclusions with a thickness that is larger than some tens of micrometers. This shows that it is necessary to use a detector which is as sensitive as possible towards high frequencies. A comparison of the current performances of infrared and Raman spectroscopies as analytical methods for investigating fluid inclusions is presented. The important improvement of better spatial resolution and the corresponding possibility of being able to characterize heterogeneities, in comparison to limitations with classical dispersive infrared spectrometry, are discussed. Methane, carbon dioxide, liquid water, aromatic ester, and linear or branched alkanes are identified in several samples. It is also possible to estimate the mean ratio of alkane CH2/CH3 groups. In some cases, the intensity of the absorptions indicates the inclusion effective thickness and the mole fraction ratio.
Enhanced Room-Temperature Phosphorescence of Anthracene on Cyclodextrin-Treated Filter Paper
Authors: Vo-Dinh Tuan , Alak Ala
Published: July 2005

This study investigates the enhancement of room-temperature phosphorescence (RTP) for anthracene when the compound is adsorbed on cyclodextrin (CD)-treated filter paper. The results show that β-CD treatment induces a significant increase in anthracene RTP emission, which is normally extremely weak. The α-CD does not produce any strong RTP enhancement, while γ-CD produces relatively lower enhancement than does β-CD. The CD treatment procedure is very simple and improves the analytical usefulness of the RTP method. The binding constants of anthracene to cyclodextrin were measured with the use of thin-layer chromatographic retention values. Anthracene has a higher binding constant with β-CD than with γ-CD, in agreement with the RTP enhancement results.
Characterization of Oxidized Nickel (II) Dimethylglyoxime Using X-Ray Photoelectron Spectroscopy
Authors: Young V. Y. , Chang F. C. , Cheng K. L.
Published: July 2005

X-ray photoelectron spectroscopy has been used to determine the oxidation state of nickel in the oxidized nickel (II) dimethylglyoxime complex. Core level binding energies for the Ni(2p), N(1s), and O(1s) levels; the presence or absence of shake-up satellites on the Ni(2p) levels; and the analysis of intensity data are consistent only with an assignment of +3. Structures consistent with the data are proposed for both the solid-and the solution-phase complexes.
Determination of Uranium in Solution Using Laser-Induced Breakdown Spectroscopy
Authors: Wachter Joseph R. , Cremers David A.
Published: July 2005

Laser-induced breakdown spectroscopy was used to determine uranium in solution for possible application to process control in nuclear fuel reprocessing facilities. Pulses from a Nd: YAG laser were focused on the surfaces of the liquids in order to generate the sparks. The spark light was spectrally resolved and detected with the use of a time-gated photodiode array. The detection limit for uranium in 4 molar nitric acid was 0.1 g/L. Measurement precisions were 1–2% for a 4.2-g/L solution with the use of 1600 laser sparks, corresponding to a measurement time of about three minutes. A calibration curve was prepared that spanned uranium concentrations from 0.1 to 300 g/L. The effects of some experimental parameters on the analysis are discussed.
Diffuse Reflectance Infrared Fourier Transform (DRIFT) Spectroscopic Studies of Coals: in situ Studies of Acetylation
Authors: Smyrl N. R. , Fuller E. L.
Published: July 2005

Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy has been utilized to monitor the in situ acetylation of a powdered subbituminous coal at the Oak Ridge Y-12 Plant. The acetylation reaction was carried out by the adsorption of acetic anhydride onto the powdered coal from the gas phase with subsequent heating above 100°C required to initiate the reaction. This technique can be used to gain insight into the hydroxyl (O-H) content of the specific coal sample under study by simultaneous observation of the disappearance of infrared absorptions due to various types of O-H functional groups and of the appearance of absorptions due to carbonyl functional groups resulting from reaction with the anhydride. This entire study can be carried out on a single sample without any intervening sample handling or the introduction of extraneous parameters that could alter the results.
Fourier Transform Infrared Analysis of Evolved Gases in Polymerization and Pyrolysis Processes
Authors: Sanchez Luis Antonio
Published: July 2005

The use of Fourier transform infrared (FT-IR) spectroscopy for characterizing evolved gases produced during polymerization and pyrolysis processes is demonstrated. Several polyimides were polymerized and the evolved gases were identified and quantitatively determined by FT-IR spectroscopy. By monitoring of the infrared absorbance of the O-H bending vibrational mode of water as a function of temperature, different sources of the evolved water were observed. We also found a correlation between the temperature at which the maximum evolution of alcohol occurs in different polyimides and the strength of the alcoxy bond to the amic acid; a comparison of the data suggests the strong dependency of the mechanism of polyimidization upon the nature of the alcoxy group. We have also studied the decomposition products of poly(ethylene terephthalate) (PET) at temperatures higher than 300°C in a nitrogen atmosphere and found that carbon monoxide, carbon dioxide, benzoic acid, and an acid para-substituted aromatic ester are the major decomposition products; these observations suggest that under the experimental conditions PET degrades by cleavage of the C-O bonds on the ethylate part of the chain and produces benzoxy and aromatic ester groups.
Direct Analysis of Solid Sample with Ultrafine Particle Generation/Inductively Coupled Plasma Emission Spectroscopy
Authors: Ono Akihiro , Saeki Masao , Chiba Koichi
Published: July 2005

An ultrafine particle generation (UFP) system has been developed for the direct analysis of solid metal samples by inductively coupled plasma (ICP) emission spectrometry. In this system fine particles are generated from solid samples with the use of a spark discharge and then swept into the ICP. The spark discharge conditions involving the electrode gap and the analytical performance of the ICP system are investigated. Analytical calibration curves are presented for steel samples. The NBS standard reference materials are analyzed by the proposed system.