bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cone‐penetrometer‐deployed Samplers and Chemical Sensors
Authors: Doskey Paul V. , Cespedes Ernesto R. 
Published: September 2006

AbstractThe development of rapid, cost‐effective, accurate methods for environmental site characterization and monitoring has been a very active area of research during the past two decades. One approach that has recently received widespread attention involves the use of cone penetrometer technologies for in situ detection and mapping of environmental contaminants in subsurface soils and groundwater. The most recent technological developments include the incorporation of on‐line analytical and in situ chemical detection techniques into the cone penetrometer. This article describes a variety of sampling and chemical sensing technologies that have been or are currently being adapted to cone penetrometer systems for the detection of subsurface contaminants, including petroleum, oils, and lubricants (POLs), volatile organic compounds (VOCs), toxic metals, explosives/energetics, and radioactive wastes. For example, cone penetrometer devices that incorporate in situ isolation techniques to purge VOCs from groundwater eliminate the analysis of the sample media in the laboratory. A high level of agreement was found between an in situ purging technique and the conventional method of bailing a sample from a groundwater sampler, transferring the sample to a container, and analyzing the sample in the laboratory. Completion of a site characterization with this probe was estimated to require approximately 15% of the time needed for conventional methods, significantly reducing costs. The laser‐induced fluorescence (LIF) sensor, which measures POLs, represents the first and most mature cone penetrometer chemical detection technology. Technology evaluations estimated that costs of site characterizations using the LIF probe are approximately 50% lower than costs of site characterizations using conventional methods for collecting soil cores, subsampling the cores, and analyzing the subsamples in the laboratory.
Field‐portable Instrumentation
Authors: Goedert Michel G. 
Published: September 2006

AbstractThe analysis of gas and vapors in the field is an important part of the remediation process. The purpose of this article is to familiarize the reader with some of the analytical instruments available today to determine the composition of gaseous samples. Although this section deals with portable instruments, it was found necessary to mention on‐site measurements since this is an important part of field measurements. On‐site measurements are done with conventional analytical instruments operating from recreational vehicles. The samples have to be collected and the first part of this article gives an overview of some of the techniques, such as canister and solid adsorbents, used for this purpose. Identification of compounds collected on‐site or directly in the field can be done by gas chromatography (GC) and mass spectrometry (MS). A comprehensive description of the hardware used with these techniques is provided.An important part of the portable section covers direct‐reading instruments such as gas sensors, electrochemical devices, ionization detectors and colorimetric detectors. These instruments provide only a limited amount of information and, most of the time, require a prior knowledge about the content of the sample. However, they are small, portable and cheaper than laboratory analytical instruments and therefore they have found a market.Portable instruments include miniaturized gas chromatographs and mass spectrometers. These instruments do not offer the high performance of their laboratory counterparts, but they give more information about the sample than direct‐reading instruments. The next step in process measurement sophistication is to combine these techniques. The most popular hyphenated technique is certainly the coupling of a gas chromatograph with a mass spectrometer, but there are also powerful and lesser‐known techniques such as GC combined with ion mobility spectrometry (IMS). IMS has found a market with military applications for the detection of chemical warfare agents. It offers less resolution than MS but operates at atmospheric pressure and is therefore truly portable. When combined with GC it offers some interesting features which will be described.
Microelectromechanical Systems Technology Applied to the Miniaturization of Field Instrumentation
Authors: Goedert Michel , Higdon William 
Published: September 2006

AbstractThis paper explores the miniaturization of analytical instruments using emerging microelectromechanical systems (MEMS) technology. MEMS provides an enabling technology base for miniaturization of many kinds. It has grown in parallel with the growth of the semiconductor industry since the discovery of silicon piezoresistance at the Bell Laboratories in the early 1950s, and borrows many principles and techniques from silicon “wafer fabs”. The technology is one of several that promises to revolutionize our lives in the 21st century.We review some of the processes developed to fabricate MEMS parts and give examples of components developed with this technology. Finally, we describe how this technology has been used to develop a portable gas chromatograph (GC) and other chemical instrumentation for the detection of gases and vapors in the field. We show, with experimental results, how analytical instrumentation can benefit from MEMS technology.
Radon, Indoor and Remote Measurement of
Authors: Cua Florence T. 
Published: September 2006

Abstract
The existing radon and radon progeny measurement instruments are described in this article. The various methods and instruments used depend on whether radon or radon/thoron progeny or daughter products are being measured, the duration of the measurement, whether short‐term or long‐term and the type of radiation being detected (alpha, beta, or gamma). The modes of detection used include the following: activated charcoal radon monitors, electret ion chamber, registration of nuclear tracks in solid‐state materials, liquid scintillation, ionization chambers, scintillation detectors with zinc sulfide, ZnS(Ag), alpha particle spectrometers with silicon diodes, surface barrier or diffused junction detectors, and gamma‐ray spectrometry with NaI(Tl) scintillation crystals or germanium lithium (GeLi) semiconductor detectors, fiber optics sensors and glass. The advantages and disadvantages will be described for various portable instruments used for measuring radon, thoron, and their daughter products. Comparison studies among the radon monitors will be included.

The reader is referred in particular to George
1
and National Council on Radiation Protection (NCRP) Report 97
2
for additional information.
Adulteration Determination
Authors: Wilhelmsen Eric C. 
Published: September 2006

AbstractDetermining adulteration in food is accomplished by comparing analytical data with historical or control data. Without a proper reference set, the determination of adulteration is impossible. Adulteration is best shown by detecting a foreign component that is characteristic of a specific adulterant. Sometimes it is necessary to use deviations in a parameter, but typically these approaches are less sensitive owing to the natural variation in food. Often practitioners are interested in the more difficult converse, that is, authentication of a product or ingredient. In practice, authenticating a product or ingredient is equivalent to not finding any adulteration. Clearly, authentication is a negative, the absence of adulteration. It can never be entirely proven. The quality of a determination of authenticity is clearly linked to number and types of tests performed. The decision not to perform a test that yields additional information increases the potential of erroneously accepting a sample.This proof of the negative challenge has led to competition between the practitioners of authentication and those who would adulterate their products or ingredients. This competition is readily apparent. Each time a useful new method has been introduced, previously undetected adulterations have surfaced. Unfortunately, the new methods generally do not supersede older methods and represent additional authentication costs. Fortunately, the vast majority of the food industry is not involved and generally cooperates in policing the marketplace.
Infrared Spectroscopy, Gas Chromatography/Infrared in Food Analysis
Authors: Mehrotra Ranjana 
Published: September 2006

AbstractInfrared (IR) radiation is usually defined as that electromagnetic radiation whose frequency is between 20 and 14 500 cm−1. Within this region of the electromagnetic spectrum, chemical compounds absorb IR radiation provided there is a dipole moment change during a normal molecular vibration, molecular rotation, and molecular rotation–vibration or from combinations, differences and overtones of the normal molecular vibrations. The frequencies and intensities of the IR bands exhibited by a chemical compound uniquely characterize the material and its IR spectrum can be used to identify and quantify a particular substance in an unknown sample. IR spectroscopy in both the mid‐infrared (MIR) and near‐infrared (NIR) regions is emerging as a qualitative as well as quantitative analytical technique with great potential in a wide range of applied areas. The prime advantage of IR spectroscopy in food applications is that once the instrument has been calibrated, several constituents in a sample can be measured rapidly and simultaneously. No sample manipulation is required. It is also applicable to on‐line analysis in the food processing industries.
Near‐Infrared Spectroscopy in Food Analysis
Authors: Osborne Brian G. 
Published: September 2006

Abstract
Near‐infrared (NIR) spectroscopy is based on the absorption of electromagnetic radiation at wavelengths in the range 780–2500 nm. NIR spectra of foods comprise broad bands arising from overlapping absorptions corresponding mainly to overtones and combinations of vibrational modes involving CH, OH and NH chemical bonds. The concentrations of constituents such as water, protein, fat and carbohydrate can in principle be determined using classical absorption spectroscopy. However, for most food samples, this chemical information is obscured by changes in the spectra caused by physical properties such as the particle size of powders. This means that NIR spectroscopy becomes a secondary method requiring calibration against a reference method for the constituent of interest. As a consequence of the physics of diffuse transmittance and reflectance and the complexity of the spectra, calibration is normally carried out using multivariate mathematics (chemometrics).
NIR spectroscopy is used routinely for the compositional, functional and sensory analysis of food ingredients, process intermediates and final products.
The major advantage of NIR is that usually no sample preparation is necessary, hence the analysis is very simple and very fast (between 15 and 90 s) and can be carried out on‐line. One of the strengths of NIR technology is that it allows several constituents to be measured concurrently. In addition, for each fundamental vibration there exists a corresponding series of overtone and combination bands with each successive overtone band approximately an order of magnitude less intense than the preceding one. This provides a built‐in dilution series which allows several choices of absorptions of different intensity containing the same chemical information. Finally, the relatively weak absorption due to water enables high‐moisture foods to be analyzed.
The major limitation of NIR spectroscopy in food analysis is its dependence on less‐precise reference methods.
Nuclear Magnetic Resonance in the Analysis of Foodstuffs and Plant Materials
Authors: de Ropp Jeffrey S. , McCarthy Michael J. 
Published: September 2006

AbstractNuclear magnetic resonance (NMR) is an experimental technique based on the interaction between an applied magnetic field and nuclear magnetic moments in a sample. NMR provides information on material composition, molecular structure, physical structure, physical properties and dynamics of phase changes. NMR is a noncontacting and noninvasive measurement. NMR has been used for the routine analysis of foodstuffs and plant materials. NMR is used in the analysis of foods to detect moisture content, solid/liquid ratio in fats, adulteration of juices and characterization of texture. Applications of NMR to plant materials include observation and characterization of metabolites and ions, determination of pH and following changes of these over time. NMR is also used to determine structures of natural products isolated from plants. Magnetic resonance imaging (MRI) is used in both foodstuffs and plant materials to study morphology and also water transport, diffusion and variations of these under different conditions. The response of NMR is linear from the detection limits of approximately 10 ppb to 100%. The accuracy of the technique depends upon the signal‐to‐noise ratio (S/N), which is a function of the sample size, applied magnetic field strength, the radiofrequency (RF) coil, the spectrometer hardware and experimental parameters. Typical accuracy is 0.5% for composition and 1–5% for viscosity.
Nuclear Magnetic Resonance in Analysis of Plant Soil Environments
Authors: Fan Teresa W.‐M. , Lane Andrew N. 
Published: September 2006

AbstractThis article presents an overview of nuclear magnetic resonance (NMR) methods and their applications in probing the metabolic processes in plants and interaction between plants and soils. The basic principles of both solution‐ and solid‐state NMR are introduced, with an emphasis on useful parameters that can be employed for determining covalent structures and conformations of biomolecules and their environmental derivatives. Both one‐dimensional (1‐D) and two‐dimensional (2‐D) NMR techniques are described, and the advantages of improved resolution and information content for the 2‐D techniques are demonstrated. The substantial improvement in the sensitivity of inverse detection methods for detecting heteronuclei is also shown. Instrumental considerations as well as sample preparation requirements are described for in vivo and in vitro applications and analysis of small and macromolecules. Applications of multinuclear 1‐D and 2‐D NMR in plant metabolism and plant–soil interactions are illustrated. These include in vivo measurements of subcellular compartmentation, determination of metabolite concentrations, enzyme or exchange kinetics, in vitro analysis of plant tissue extracts and root exudates, use of stable isotope tracers for analysis of biochemical pathways, and structural and conformational characterization of natural organic matter (NOM) from soils and sediments. The relative advantages and disadvantages of solution‐ and solid‐state NMR techniques for analysis of plant–soil systems are discussed with examples from characterization of NOM, although 1‐D13C solid‐state methods have been of choice due to the polydispersive nature and low aqueous solubility of NOM. However, recent advances in 2‐D solution‐state methods are presented that provide valuable information on structure, conformation, and ligand binding of NOM, which is not practical by solid‐state methods. The limitations of NMR analysis for in vivo, in vitro and NOM are noted, along with a discussion on future prospects for NMR analysis in terms of spectral resolution and detection limits achievable.
Particle Size Analysis in Food
Authors: Robins Margaret M. 
Published: September 2006

Abstract
Techniques are described for determining particle size in food dispersions involving food particles ranging in size from 0.1 to 1000 µm, where the presence of the particles confers special properties such as texture, appearance or flavor release. Those foods of plant origin that are cellular in nature are outside the scope of this article, as their structure is not under the control of the food manufacturer. The techniques described are used to a greater or lesser extent on foods, and they are all methods in use in other industrial sectors. The techniques are classified according to their underlying physical principle. Summary tables are provided to act as quick reference guides for a potential user of the technique. After the detailed descriptions, the final section groups those techniques relevant to a specific type of dispersion.
The two most direct methods, microscopy and sieving, are discussed initially followed by three classes of optical technique, comparatively simple forward or back scattering, angular‐dependent light scattering and dynamic light scattering. The next technique to be addressed is the electrical sensing zone originally developed by Coulter. Sedimentation techniques follow: gravitational sedimentation, centrifugal sedimentation and field‐flow fractionation (FFF). All depend on the behavior of the particles in a force field that is balanced by viscous drag forces. The next two techniques are both acoustic in operation, either direct ultrasonic attenuation or electroacoustics. Finally, the novel applications based on nuclear magnetic resonance (NMR) are presented.
Pesticides, Mycotoxins and Residues Analysis in Food
Authors: Volante M. , Branca P. 
Published: September 2006

AbstractThis article will deal with methods for analyzing residues of pesticides and mycotoxins from molds in food. A general description of each topic is given directing the reader towards some key reviews, books or manuals published in the field with specific references added for more recent papers or topics of particular interest; techniques such as chromatography, spectrophotometry and immunochemical methods have been reviewed. In the first section sampling procedures are discussed, in the second section an overall description of the analytical methods used for pesticide residues in food is given with particular attention to multiresidue methods, in general those used most for assessing residue levels in crops at the international level, with consideration given to those less used methods dedicated to specific compound classes not covered elsewhere. The third section deals with mycotoxins with a brief description of the various mycotoxin types and some properties, followed by some discussion of analytical methods. The description of analytical techniques has been divided into extraction, cleanup and instrumental determination techniques for both pesticides and mycotoxins. Some tables of experimental data are also given.The last section (four) deals with quality assurance aspects outlining the necessary steps, included interlaboratory trials, needed to validate a method and to assure reliability of the data.
Proteins, Peptides, and Amino Acids Analysis in Food
Authors: Dierckx Stephan , Boeve Karen , Van Camp John , Huyghebaert André 
Published: September 2006

AbstractProteins are an important fraction in most foodstuffs, ranging from 1.8% in roots and tubers up to about 25% in legumes.1However, in foods they are present in a complex multicomponent matrix also containing water, lipids, carbohydrates, and some minor components, all of which might interfere during the analysis of proteins in foods. A whole variety of analytical tools for protein analysis are available to the analyst2but not all of them are suitable for routine analysis procedures. This article will deal with some key analytical techniques in order to give an overview of possibilities and shortcomings of current techniques and some promising future trends. Well established methods are the Kjeldahl method, spectroscopy in the ultraviolet (UV), visible (VIS), and infrared (IR) ranges of the spectrum, chromatography, and conventional electrophoresis, while recent developments are to be found in the field of capillary electrophoresis (CE) and immunoassay. Since validation of methods and results are important features of today's analysis, some attention is paid to the availability and use of reference materials.
Proximate Assays in Food Analysis
Authors: Nielsen S. Suzanne 
Published: September 2006

AbstractThe proximate composition of foods includes moisture, ash, lipid, protein, and carbohydrate contents. These food components may be of interest in the food industry for product development, quality control (QC), or regulatory purposes. Analyses used may be rapid methods for QC or more accurate but time‐consuming official methods. Sample collection and preparation must be considered carefully to ensure analysis of a homogeneous and representative sample, and to obtain accurate results. Specific methods of analysis for moisture, ash, lipid, protein, and carbohydrate are described in this article, focusing on the principle of each method, application, and sources of error.
Sample Preparation Analytical Techniques for Food
Authors: Rothaupt Michael 
Published: September 2006

Abstract
Sample preparation is one of the important steps in flavor and food analysis. Thermal extraction (TE) of volatile substances simplifies sample preparation by separating volatile compounds from nonvolatile ones. A temperature vaporizing program allows additional prefractionation of the analytes. Solvent venting (SV) supports chromatography by removing a large amount of the solvent. SV also helps eliminate interfering and problematic ingredients from the sample. Sample preparation by supercritical fluid extraction (SFE) is compared to TE, with specific advantages and disadvantages being discussed.
Starch Analysis in Food
Authors: Englyst Klaus N. , Hudson Geoffrey J. , Englyst Hans N. 
Published: September 2006

Abstract
Starch is quantitatively an important component of the human diet, being present in grains, tubers and legumes. Starch has for a long time been considered by many as being slowly but completely digested in the small intestine, resulting in modest glycemic responses and with no physiological role other than as an energy source. It is now understood that in fact the metabolic fate and physiological properties of starch can vary considerably, and both the botanical source and the effects of food processing are major determinants of starch digestibility. In addition to the nature of the starch itself, the site, rate and extent of digestion of starch in the human small intestine are influenced by a number of host factors. The rate at which starch is digested in the human small intestine results in a wide range of glycemic responses, and this physiological measurement has been used to rank foods by their glycemic index. In vitro studies have indicated that glycemic response and the rate of starch digestion are closely correlated. Rapidly digestible starch (RDS) and slowly digestible starch (SDS) fractions together represent the starch that is likely to be digested completely in the human small intestine, with any remaining starch defined as the resistant starch (RS) fraction that is available for fermentation in the large bowel. Measurements of RDS, SDS and RS can be obtained by one simple procedure. Values for the different starch fractions obtained by the in vitro method described here represent reproducible measurements that can be used to classify dietary starch according to its potential digestibility. In addition to these starch fractions, two terms, rapidly available glucose (RAG) and slowly available glucose (SAG), are introduced to reflect the rate at which glucose (from both sugars and starch) is likely to be absorbed in the small intestine.
The proportions of RAG, SAG, RDS, SDS and RS in foods can be controlled by food processing. The implications of altering the rate and extent of starch digestion are potentially of great importance to public health. A full understanding of the links between dietary carbohydrates and health and the underlying mechanisms will come only from the specific measurement of individual types of dietary carbohydrates.