bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lubricant Base Oils: Analysis and Characterization of
Authors: Shugarman Arnold L. 
Published: September 2006

AbstractLubricant base oils, or base stocks, are hydrocarbon lubricant components which are combined with performance additives to make finished industrial and automotive lubricants. A lubricant is a substance that reduces friction and wear between surfaces. Base oils typically comprise 80–99% of the finished lubricant. They are refined from selected crude oils, re‐refined from used oil, synthesized from specific organic compounds, or extracted from renewable resources, such as seed oils. Base oils formulated into finished lubricants help to reduce friction and wear between moving surfaces, remove heat, seal, cushion against shock loads, and remove abrasives and contaminants from the lubricated area. Base oil analysis and characterization is important for understanding how the physical and chemical properties of these materials relate to performance in finished lubricants. It is also essential for maintaining quality control (QC) over the manufacturing process, for quality assurance (QA) of the finished product, and for setting specifications between buyer and seller.
Nuclear Magnetic Resonance Characterization of Petroleum
Authors: Miknis Francis P. , Netzel Daniel A. 
Published: September 2006

AbstractNuclear magnetic resonance (NMR) spectroscopy is a powerful analytical method for determining the structure of an organic material. Developments in NMR have allowed high‐resolution spectra of materials in the solid state to be obtained. Thus, materials that have been intractable, such as kerogens and sedimentary organic matter, can now be characterized for their organic carbon structure. The combination of solid‐ and liquid‐state NMR makes NMR one of the most useful methods for the characterization of petroleum and its products.Petroleum is formed from the maturation of sedimentary organic matter as a result of burial over geological timescales. Everyone is familiar with the products of petroleum, i.e. gasoline, diesel fuels, chemicals, and so on. All these materials, including the petroleum source rock material, can now be studied by NMR, from the genesis of petroleum to finished products such as transportation fuels. In this article, some applications of solid‐ and liquid‐state NMR to the characterization of petroleum source rocks and petroleum end products are described.
Oxygenate Vapor–Liquid Equilibrium in Gasolines
Authors: Sandler Stanley I. , Marsh Kenneth N. 
Published: September 2006

Abstract
Ethers and alcohols are being added to hydrocarbon fuels to produce the current generation of “clean gasolines” which are claimed to reduce air pollution. Also, alcohols provide a renewable energy source. However, the addition of oxygenates can change the volatility (as measured by the Reid vapor pressure) of a hydrocarbon mixture. This article reviews the equipment and measurement methods commonly used to study the vapor–liquid equilibrium (VLE) of hydrocarbon–oxygenate and gasoline–oxygenate mixtures. Detailed tables present those oxygenate–hydrocarbon mixtures for which VLE data are available.
Oil Shale and Shale Oil Analysis
Authors: Miknis Francis P. , Netzel Daniel A. 
Published: September 2006

AbstractAn oil shale can be defined as a compact rock of sedimentary origin with an ash content of more than 33% and containing organic matter that yields oil when destructively distilled, but not appreciably when extracted with ordinary solvents. This is an operational definition. There is no geological or chemical definition of an oil shale. The term is used mostly in an economic sense so that any shallow rock that yields a commercial amount of oil upon pyrolysis may be considered an oil shale. Oil shale deposits occur in at least 50 countries and the estimated potential world supply of oil from shale is 5 × 1012barrels.The organic matter in an oil shale is mostly in the form of kerogen, which is defined as that fraction of the organic matter in a sedimentary rock that is insoluble in common petroleum solvents. The insolubility of kerogen is the main reason why an oil shale must be heated to produce liquid products. The amount of shale oil that can be produced by heating an oil shale is normally obtained from a Fischer assay. However, the Fischer assay is somewhat time‐consuming and does not provide information about what chemical properties of oil shales are important for producing liquids. Consequently, a number of alternative procedures have been developed to analyze oil shales. These procedures, along with methods of analyzing shale oils, are described in the following sections.
Mass Spectrometry, Low‐Resolution Electron Impact, for the Rapid Analysis of Petroleum Matrices
Authors: Nero Vincent P. 
Published: September 2006

Abstract
Common industrial analytical procedures determine the overall physical or chemical characteristics of a petroleum product, which are necessary to market the product, but these methods provide little or no information concerning specific chemical components. This article focuses on standard methods which can be used to determine the composition of individual components or classes of components within various petroleum matrices. Gas chromatography (GC) coupled with low‐resolution mass spectrometry (MS) is the most useful method for quickly identifying and precisely measuring specific components or classes of components in a petroleum matrix. Direct insertion probe mass spectrometry/mass spectrometry (DIP/MS/MS) can be used for less volatile and thermally labile petroleum components.
Chemical Reagents and Derivatization Procedures in Drug Analysis
Authors: Danielson Neil D. , Gallagher Patricia A. , Bao James J. 
Published: September 2006

AbstractThis article describes both pre‐ and postcolumn derivatization chemistry used in conjunction with either chromatography or capillary electrophoresis (CE) to facilitate the determination of drugs. Generally, only prederivatization is used in gas chromatography (GC), principallyto enhance the volatility, temperature stability, and/or detectability. The GC section considers derivatization of drugs by reagent class: alkylation, acylation, and silylation. The GC sample handling section describes an approach which combines the extraction and derivatization steps together. Both pre‐ and postcolumn derivatization are common approaches for high‐performance liquid chromatography (HPLC) and many of these methods have been adapted for CE. Derivatization for HPLC is often directed toward aliphatic amines, carboxylic acids, or alcohols that are difficult to detect at low levels by absorbance, luminescence, or electrochemical means. In addition, small hydrophilic molecules upon prederivatization are often converted into larger more hydrophobic compounds, making reversed‐phase HPLC easier or even feasible. The HPLC section considers derivatization of drugs based on type: alkaloids, amines, antibiotics, barbiturates, carbonyl compounds and carboxylic acids, catecholamines, hydroxy compounds, steroids, and sulfur compounds. For the GC and HPLC sections, tables are included giving the structures of the more important derivatizing agents, the analytes, and the corresponding reaction products. A brief rationale for derivatization chemistry with CE concludes this article. For CE, derivatization is often done to improve detectability since the path length for absorbance detection is very short and fluorescence can be effective using laser‐based systems.
Chiral Purity in Drug Analysis
Authors: Machida Yoshio , Nishi Hiroyuki 
Published: September 2006

AbstractThe preparation and evaluation of optically active compounds have become very important for the development of new drugs. The determination of chiral purity of drugs is essential in order to guarantee safety and effectiveness. Isomeric impurities may have unwanted toxicological, pharmacological, or other side‐effects. Therefore we decided to prepare an article entitled “Chiral purity in drug analysis”. This article is divided into five sections (introduction, production, regulation, evaluation methods and conclusion). In the introduction, the importance of assessing the isomeric impurities in drug analysis will be discussed. In the second section, production methods for optically active compounds, except the stereoselective synthesis method, will be summarized briefly. In particular, new trends in the production of chiral drugs, such as the simulated moving beds (SMB) method, will be described. In the third section, regulatory perspectives in the USA (Food and Drug Administration (FDA)), EC, and Japan will be described and some regulatory guidelines and guidances by, for example, the FDA, the Committee for Veterinary Medicinal Products (CVMP), and the International Conference on Harmonization (ICH) will be mentioned. In the fourth section, methods for the determination of stereoisomeric drugs will be summarized. Methods such as gas chromatography (GC), high‐performance liquid chromatography (HPLC), and capillary electrophoresis (CE) have been summarized. The focus will be on direct evaluation methods, i.e. those using chiral stationary phases (CSPs). Practical details for testing a drug's optical purity are also given.
Combinatorial Chemistry Libraries, Analysis of
Authors: Kibbey Christopher E. 
Published: September 2006

AbstractMany of the analytical techniques applied to the analysis of traditional pharmaceutical compounds are used to characterize combinatorial chemistry libraries. In both cases, the medicinal chemist is primarily concerned with verifying the identity and purity of the compounds synthesized. The identity of a compound usually is confirmed spectroscopically by Fourier transform infrared (FTIR) spectroscopy, mass spectrometry (MS), and/or nuclear magnetic resonance (NMR) spectroscopy, while purity is determined using a chromatographic technique, such as high‐performance liquid chromatography (HPLC). Combinatorial chemistry libraries may contain 100–100 000 compounds present as single species or as mixtures. The need to efficiently characterize such large numbers of compounds has been the primary motivation behind the development of many of the chromatographic–spectroscopic techniques applied to the analysis of combinatorial chemistry libraries. Many of these techniques have utility outside of the realm of normal library characterization. For example, the combination of affinity chromatography and MS has proven useful for screening combinatorial chemistry libraries against specific biological targets. The major impediments to the analysis of combinatorial chemistry libraries have been the challenges of designing analytical methods compatible with the wide chemical diversity of compounds encountered in these libraries, and the unique sample preparation and handling requirements imposed by combinatorial synthesis.
Planar Chromatography in Pharmaceutical Analysis
Authors: Argekar A.P. 
Published: September 2006

Abstract
Planar chromatography is a liquid chromatography in which the stationary phase is arranged in the form of a planar or flat bed and the mobile phase moves by capillary action. Thin‐layer chromatography (TLC) is the most widely used planar chromatography. Modern TLC is an instrumental version of conventional TLC known as high‐performance thin‐layer chromatography (HPTLC). Rotation planar chromatography (RPL), high‐speed thin‐layer chromatography (HSTLC), and over‐pressured liquid chromatography (OPLC) are some other forms of planar chromatographic methods.
The application of HPTLC techniques for pharmaceutical analysis, such as the determination of active pharmaceutical ingredients (API) and the content uniformity test (CUT) of dosages, purity and stability tests of drugs and drug products, process monitoring of formulations, and herbal drug analysis, is described in this article. The method development of the high‐performance liquid chromatography (HPLC) technique, various pharmaceutical regulations and methods, validation and quality assurance (QA) of HPTLC experimental data and documentation are also described. The comparison of HPTLC with other chromatographic techniques is also discussed.
Proteins and Peptides Purification in Pharmaceuticals Analysis
Authors: Thrash Marvin E. , Pinto Neville G. 
Published: September 2006

AbstractThe biopharmaceutical market has exploded in the last 10 years, with annual sales easily exceeding a billion dollars per year. Analysis and purification are essential components in the production of therapeutic proteins and peptides, and chromatography is at the core of all pharmaceutical separations. The more popular chromatographic techniques used in the purification of proteins and peptides are reversed‐phase chromatography (RPC), hydrophobic interaction chromatography (HIC), ion‐exchange chromatography (IEC), affinity chromatography (AC) and size‐exclusion chromatography (SEC). In order to meet the challenges of the future it is essential to understand the fundamentals of each technique. In this article an overview of the more popular chromatographic techniques employed to purify biomolecules is presented. Relevant examples are also given and a discussion of detection and scale‐up is provided.
Solid‐Phase Extraction and Clean‐Up Procedures in Pharmaceutical Analysis
Authors: Campíns‐Falcó P. , Sevillano‐Cabeza A. , Herráez‐Hernández R. , Molins‐Legua C. 
Published: September 2006

Abstract
Solid‐phase extraction (SPE) using small cartridges filled with sorbents of a small particle size has rapidly established itself as an important sample clean‐up technique. It has prospered at the expense of liquid–liquid extraction (LLE) which is considered labor intensive and frequently plagued by problems, such as emulsion formation and use of large volumes of hazardous solvents. A remarkable characteristic of SPE is its easy adaptation to on‐line mode by column switching techniques; switching can be effected manually or by automated controllers.

The same analyte/sorbent interactions that are exploited in liquid chromatography (LC) are of use in SPE, but particle sizes employed are greater. Chemically bonded silica (SI), usually with C
18
and C
8
organic groups, is by far the most commonly used material. At present, cross‐linked polystyrene and other polymeric resins and mixed‐mode SPE sorbents are finding increasing use. A guide to improve sample clean‐up procedure can be established.

There are different approaches to automation for both off‐line and on‐line SPE, which involve different levels of apparatus cost. SPE is generally easier and cheaper than LLE. The precision obtained is similar for both techniques, while the recoveries obtained by SPE are generally better than those obtained by LLE.
Enrichment and derivatization can also be carried out by use of sorbents as supports.
Steroid Analysis
Authors: Bailey Leonard C. , Medwick Thomas , Dong Yijie 
Published: September 2006

AbstractThe successful determination of steroids in dosage forms and biological samples presents particular problems to the analyst in view of the great number of members of this class and their varied properties. This article discusses, according to their medicinal categories, the various classes of steroids and steroid‐like compounds which can be encountered by the pharmaceutical analyst, the general methods used in their determination, and the application of these methods to nine classes of steroidal substances.
Vibrational Spectroscopy in Drug Discovery, Development and Production
Authors: Tomellini Sterling A. , Finn James W. 
Published: September 2006

Abstract
The area of vibrational spectroscopy encompasses a number of versatile analytical techniques, many of which have been applied successfully to a wide variety of pharmaceutical analyses. While there are many vibrational spectroscopic techniques, some more esoteric or generally applicable than others, this chapter will concentrate on pharmaceutical applications limited to three specific areas: near‐infrared (NIR) spectroscopy, mid‐infrared (MIR) spectroscopy and Fourier transform Raman spectroscopy (FTRS). The goal of this work is to provide the interested reader with the background necessary to better understand these vibrational spectroscopic techniques and provide an overview of the breadth of applications for these techniques in analyses of pharmaceutical importance. Recently reported applications will be emphasized. The wide variety of sampling methods associated with these techniques will be highlighted throughout. Recent developments which are expected to have an impact on future pharmaceutical applications will also be discussed. Literature and other resources for advanced study are also provided.
Atomic Force Microscopy in Analysis of Polymers
Authors: Magonov S.N. 
Published: September 2006

AbstractAtomic force microscopy (AFM), in which a sharp probe is employed for profiling surfaces with unique resolution, has developed into an invaluable multidisciplinary technique for advanced characterization of polymer materials. In its basic function, AFM provides high‐resolution imaging of surface structures between the scales of a few nanometers to hundreds of micrometers. This capability is useful for quantitative analysis of surface microroughness of technological surfaces with high sensitivity and accuracy. The direct visualization of polymer structures, from single macromolecules to granular and lamellar nanostructures, to microphase separation and other morphologic patterns, makes AFM an important complementary tool for many of the techniques (light scattering, chromatography, optical and electron microscopy, X‐ray diffraction analysis, etc.) employed in polymer analysis.The advances in AFM of polymers are related to a better understanding of tip–sample force interactions and their use for examination of local sample properties. Different responses of the probing tip to surface locations with different mechanical and adhesive properties are the key for compositional imaging of heterogeneous polymer systems. Compositional mapping with AFM, which does not require any special sample treatment, substantially enhances its microscopic value. Visualization of individual components in block copolymers, polymer blends and semicrystalline materials can be performed with nanometer resolution. In addition to lateral compositional imaging, AFM probing of subsurface structures can be achieved for polymer samples with rubber‐like top layers.A further expansion of AFM applications is expected with the imaging of polymers at different temperatures. Monitoring of polymer structural changes at thermal phase transitions could help in the understanding of polymer melting, crystallization, recrystallization, glass transition and physical aging. In such applications, AFM will complement various thermal techniques.The review describes the basics of AFM, practical aspects of its applications to polymers and presents a broad range of examples illustrating the main trends in AFM of polymer materials.
Dielectric Spectroscopy in Analysis of Polymers
Authors: Schultz John W. 
Published: September 2006

Abstract

Dielectric spectroscopy is the measurement of complex permittivity (or “dielectric constant”) as a function of frequency. This measurement can also be done as a function of temperature or time at fixed frequencies to determine various physical and chemical properties of a given polymer. The permittivity is usually measured by placing the sample in contact with electrodes and applying a sinusoidal voltage. Permanent and induced dipoles, and also ion or electron conduction, all contribute to the dielectric response of a material. Dielectric spectroscopy can be used to probe molecular relaxation processes in polymers such as the glass transition or phase transitions such as a melt. For many of the relaxations, it is among the most sensitive of the thermal analysis techniques. Dielectric spectroscopy can also be used to follow chemical changes in polymer systems, such as polymer cure or aging. Because of its enormous frequency range (10
−6
–10
12
Hz), dielectric spectroscopy can follow a wide variety of phenomena. However, since it requires either dipole rotation or charge transport, there are some molecular processes that may not be dielectrically active. In addition, analysis of the measured data can be difficult when there are different phenomena occurring simultaneously.
Dynamic Mechanical Analysis of Polymers and Rubbers
Authors: Menard Kevin P. , Bilyeu Bryan W. 
Published: September 2006

AbstractDynamic mechanical analysis (DMA) is the technique of applying a stress or strain to a sample and analyzing the response to obtain phase angle and deformation data. These data allow the calculation of the damping or tan δ, storage, loss, and complex modulus, complex viscosity and compliance. Two approaches are used: (a) forced frequency, where the signal is applied at a set frequency, and (b) free resonance, where the material is perturbed and allowed to exhibit free resonance decay. Most DMAs are the former type while the torsional braid analyzer (TBA) is of the latter. In both approaches, the technique is very sensitive to the motions of the polymer chains and it is a powerful tool for measuring transitions in polymers. It is estimated to be 100 times more sensitive to the glass transition than differential scanning calorimetry (DSC) and it resolves other more localized transitions not detected in DSC. In addition, the technique allows the rapid scanning of a material's modulus and viscosity as a function of temperature or of frequency. DMA may also be referred to as dynamic mechanical thermal analysis (DMTA), dynamic mechanical spectroscopy (DMS), or dynamic thermomechanical analysis (DTMA).
Infrared Spectroscopy in Analysis of Polymer Structure–Property Relationships
Authors: Pennington Brian D. 
Published: September 2006

Abstract
Infrared (IR) spectroscopy is the measurement of the intensity of IR radiation absorbed at specific wavelengths, which can be used for the characterization of solid, liquid, gas, fiber, and powder samples. This technique allows molecular level identification of surface, interfacial, and bulk regions owing to its high selectivity and sensitivity. Quantitative measurement of molecular functionalities is accomplished by comparison with standards of known concentrations. The IR spectroscopic methods covered in this article include transmission, internal reflectance, reflection–absorption, diffuse reflectance, photoacoustic (PA), and step‐scan techniques. Common applications of IR spectroscopy include polymer blending, adhesion, surface analysis, kinetics, and multidimensional studies.
The molecular specific information IR spectroscopy provides is one of the most useful aspects of this technique when compared to other common analytical methods. Compared with gas chromatography/mass spectrometry (GC/MS) which reaches parts per billion detection limits, IR spectroscopy, which is much less sensitive, provides nondestructive analysis. The depth resolution of X‐ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) is several orders of magnitude better than IR spectroscopy, yet the ultrahigh vacuum (UHV) operating conditions of these techniques would destroy volatile samples. While the lateral resolution of scanning electron microscopy (SEM), energy‐dispersive X‐ray analysis (EDX), and transmission electron microscopy (TEM) techniques is superior to IR spectroscopy, these methods require tedious sample preparation. IR spectroscopy offers sensitivity to a wide range of samples with limited sample preparation needed.