bluuebunny/crossref_metadata_2025 huggingface dataset:
Wavenumber Standards for
R
aman Spectrometry
Authors: Carrabba Michael M.
Published: September 2006

This chapter describes the use of wavenumber standards for the calibration of Raman instruments. Methods using both The American Society for Testing and Materials (ASTM) Raman shift standard, which was developed to provide accurate wavenumber shifts from readily available commercial materials, and the use of atomic based lines are presented. The Raman shift standard materials have an advantagein that they can then be utilized to calibrate any Raman spectrometer, including spectrometers that use variable excitation sources. They provide an easy way to routinely calibrate an instrument using the actual collection geometry of the apparatus. The use of atomic based lines can provide a more accurate calibration of a spectrometer.

Raman shift standard, calibration, wavenumber, atomic lines, ASTM, 4‐acetamidophenol.
Sampling Techniques in Near‐Infrared Transmission Spectroscopy
Authors: Ozaki Yukihiro , Berry Ronald James
Published: September 2006

The sections in this article are

Introduction

Characteristics of Near‐Infrared Transmission Spectroscopy

Sampling Techniques

Liquid and Solution Samples

Solid Samples

Gas Samples

Online Analysis
Open‐Path
F
ourier Transform Infrared Spectroscopy
Authors: Russwurm George M. , Childers Jeffrey W.
Published: September 2006

The sections in this article are

Introduction

Historical Perspective

Current State of the Art

Principles of

OP
/
FT
‐
IR

Monitoring

Optics

Transfer Optics

Telescopes

Retroreflectors

IR
Sources

Detectors

Monitoring Configurations

Monostatic Configurations

Bistatic Configurations

Siting and Selection of Monitoring Paths

Data Acquired

B
eer's Law

Interferograms and Single‐Beam Spectra

Background Spectra

Absorption Spectra

Concepts of Path‐Averaged and Path‐Integrated Concentrations

Instrumental Parameters

Measurement Time

Spectral Resolution

Apodization and Zero Filling

Atmospheric Effects

Data Analysis

Preparation of Field Spectra for Analysis

Correcting Single‐Beam Spectra for Stray Light or Ambient Radiation

Baseline Correction

Correcting Absorption Spectra for Wavenumber Shifts

Generating Reference Spectra

Analysis Methods

Nonlinear Response

Quality Control Issues

Measurement of the Random Noise

Relative Intensities in Single‐Beam Spectra

Time Series Plots

Correlation Plots

Statistics from Multivariate Analyses

Estimation of Detection Limits

Accuracy and Precision

Measurement of Permanent Gases

Short Cell

Comparability

Applications

Future Directions
Reflection–Absorption Spectroscopy of Thin Films on Metallic Substrates
Authors: Umemura Junzo
Published: September 2006

The sections in this article are

Introduction

Mathematical Treatments and Characteristics of

RAS

Isotropic Film

Uniaxial Film

Evaluation of Molecular Orientation Using

RAS

Comparison with
KBr
Pellet Spectra

Comparison with Transmission Spectra on

IR

‐Transparent Substrates

RAS

Measured with Unpolarized Light

Application to the Study of Thin Films

L
angmuir–
B
lodgett Films

Self‐Assembled Monolayers

Vacuum‐Evaporated Films

Conclusion
Infrared Spectrometry of Thick Organic Films on Metallic Substrates
Authors: Merklin Gregory T.
Published: September 2006

The sections in this article are

Introduction

Optical Theory

Computational Implementation

Computational Results

General

Effects of Film Thickness

Calculations with Respect to Angle

Determination of Adherence to
B
eer's Law

Experimental

General

Polystyrene Films

Beverage‐Can Lining Film

Results and Discussion

Results for Polystyrene Samples

Beverage Can Samples

Changes with Respect to Angle

RAIRS

vs Transmission Spectra

Analysis of

s

‐Polarized Spectra

Conclusions

Acknowledgments
F
ourier Transform Surface Plasmon Resonance
Authors: Corn Robert M. , Weibel Stephen C.
Published: September 2006

The sections in this article are

Introduction to
F
ourier Transform Surface Plasmon Resonance

Surface Plasmon Resonance in the Near‐Infrared

Experimental
F
ourier Transform Surface Plasmon Resonance

Applications of
F
ourier Transform Surface Plasmon Resonance Measurements
Infrared Spectroscopic Ellipsometry
Authors: Röseler Arnulf , Korte Ernst‐Heiner
Published: September 2006

The experimental and the evaluation methods of infrared ellipsometry are outlined. The results provide a highly reliable basis for further interpretation, for example, material properties or molecular orientation. Various applications demonstrate the scope of the method.

Infrared ellipsometry is a reflection technique for determining the optical properties of a sample. It is advantageously employed to characterize layers down to nanometer thickness. The two experimental results obtained per spectral data point can be evaluated for the sample's optical constants (refractive and absorption index or the complex dielectric function) by strict application of optical theory. In addition, the layer thickness is available since it is independent of the wavelength and the generally applied interferometers cover a wide spectral interval. The evaluation can be extended to anisotropic optical properties.
Principles, Theory and Practice of Internal Reflection Spectroscopy
Authors: Mirabella Francis M.
Published: September 2006

The theoretical principles of internal reflection spectroscopy (IRS), also known as attenuated total reflectance (ATR) spectroscopy, are discussed. The origin of the absorption spectra in the IRS configuration with a lower refractive index sample material in contact with the higher refractive index internal reflection element (IRE) is described. The significance and differences in the depth of penetration and the effective thickness parameters are discussed in detail. An experimental strategy is described for the determination of the actual depth of sampling into the rarer sample material, and the quantitative comparison of the so‐determined “sampling depth” is compared to the theoretical depth of penetration. A comparison of the thick (bulk) film and thin film cases is given. A discussion of the practical considerations necessary to perform experimental IRS measurements is given, including necessary considerations for quantitative calibration. Several results of quantitative determinations on polymers are presented to exemplify the calibration procedures.
Optics and Sample Handling for Near‐Infrared Diffuse Reflection
Authors: Eilert Arnold J. , Wetzel David L.
Published: September 2006

The sections in this article are

Introduction

Fundamentals of Near‐Infrared Diffuse Reflection Analysis

Characteristics of Diffusely Reflected Radiation

Measurement of Diffusely Reflected Radiation

Special Considerations for Quantitative Analysis

General Spectrometer Design Considerations for Near‐Infrared Diffuse Reflection Analysis

Sample Preparation and Presentation

Powders, Granulates, and Grains

Liquids and Pastes

Intact Solids and In‐Container Sampling

On‐Line Sampling Strategies

Diffuse Transmission for Special Applications

Diffusely Reflected Near‐Infrared Radiation Collection Schemes

Integrating Spheres

Close Proximity Detectors

Bifurcated Fiber Optic Emitters/Receptors

Special Optics for Small Samples

Noncontact/Remote Sampling Optics

Diffuse Reflection Reference Measurements
Integrating Spheres for Mid‐ and Near‐Infrared Reflection Spectroscopy
Authors: Hanssen Leonard M. , Snail Keith A.
Published: September 2006

The sections in this article are

Introduction

Terminology

Historical Review

Theory of Sphere Throughput

Reflectance Techniques

Absolute Reflectance Methods

Relative Reflectance Methods

Dealing with Error Sources: Sphere Design Considerations

Detector Field of View and Sphere Symmetry

Baffle Design

Coating and Sample

BRDF

Flat versus Curved Samples

Port Design

Modern Sphere Instrumentation for Spectroscopy

Summary and Discussion

Disclaimer

Appendix
Morphology‐Dependent
R
aman Measurements
Authors: Popp Jürgen , Kiefer Wolfgang
Published: September 2006

The sections in this article are

Introduction

Trapping of Single Particles

Laser Light Traps for Studying Single Microparticles

Electrodynamic Trap

Morphology‐Dependent Resonances

R
aman/
Mie
Scattering from Single Levitated Microparticles

Evaporation Behavior of Single Microdroplets

Chemical Reactions in Single Microdroplets

Microparticle Investigations Using an Optical Gradient Force Trap

Single Laser‐Trapped Dielectric Microparticles

Single Laser‐Trapped Gas Bubbles

Acknowledgments
Instrumentation forFT‐IRImaging
Authors: Kidder Linda H. , Haka Abigail S. , Lewis E. Neil
Published: September 2006

Infrared (IR) spectroscopic imaging is the complete synthesis of IR spectroscopy with sample visualization and greatly extends the capabilities of conventional IR spectroscopy. The technique can be used to explore the heterogeneity of a single sample, or as a parallel spectroscopic technique to characterize multiple samples simultaneously. The historical development of IR arrays, one of the key enabling technologies, is discussed. Current instrumental implementations, design criteria specific to imaging systems, and signal‐to‐noise considerations for step‐scan systems are presented. One of the benefits of vibrational spectroscopic imaging is the vast amount of spectral and spatial data that is obtained. To optimize data mining strategies for these data sets, a variety of multivariate and statistical approaches are summarized. Specific applications in polymer, agricultural, and biomedical fields are shown, which serve to elucidate the varied applications and utility of the technique.
Near‐Infrared Microspectroscopy
Authors: Hammond Stephen V. , Clarke Fiona C.
Published: September 2006

Microscopic near‐infrared (NIR) spectroscopy can provide low‐level matrix information on the composition and distribution of ingredients within an intact pharmaceutical blend or tablet. NIR spectral data can be collected either by point‐by‐point spectral acquisitions (point mapping) or by global illumination of the sample (global imaging) and by image collection at individual wavelengths. On combination, these wavelength images create a hyperspectral data cube, whereby following a defined pixel through the data cube gives rise to an NIR spectrum. Therefore, both techniques provide similar information with both the spectral and spatial characteristics of the sample obtained.

Microscopic NIR has potential applications for pharmaceutical analysis, although there are on‐going discussions about appropriate analysis conditions and the actual contributing volume to a single spectrum. The latter obviously impacts spectral interpretation, and as such a wide range of analysis tools are used to obtain a chemical image. Using microscopic NIR, four different pharmaceutical issues have been examined, from pretabletting blends through final dosage forms. By use of multivariate and image analysis methods it has been possible to extract useful chemical information and create ‘visual’ images of the sample. These images provide information on the size, shape, and distribution of each component within the formulation. This information has been utilized in studies of flow issues, tablet sticking and chipping during manufacture, and understanding moisture uptake in dosage forms.

Microscopic NIR has been used to improve knowledge and understanding of pharmaceutical processes and potentially, with increased acquisition and processing time, could be used to control pharmaceutical production.
General Introduction to Fiber Optics
Authors: Lewis I.R. , Rosenblum S.S.
Published: September 2006

Their excellent transmission capabilities coupled with mechanical flexibility has led optical fibers to be deployed as sampling accessories in the field of vibrational spectroscopy. In this chapter, an introduction to basic terms such as numerical aperture, acceptance angles, overfilling, underfilling, bend radius, core, cladding, single‐mode fibers, multimode fibers, step and graded index fibers is provided. The general principles of operation of optical fibers and a broad background of some of the important issues surrounding the use of optical fibers in spectroscopy are given. The suitability of the different types of optical fibers for specific spectroscopic measurements is discussed.
Fiber‐Optic Probes forRaman Spectrometry
Authors: Lewis Ian R. , Lewis Mary L.
Published: September 2006

Historically, one of the limitations to the acceptance of Raman spectrometry outside the photonics laboratory has been sampling. Despite the fact that common containers such as cuvettes, glass bottles, and plastic bags can be used as sample holders, alignment of these holders to a Raman instrument using 90° geometry had relegated Raman spectrometry to the realm of the researcher. Fiber‐optic probe designs using both a 180°‐backscatter geometry and the flexibility of fiber‐optic cables coupled to a new generation of Raman analyzers have tremendously increased sampling ease and applicability. Now the analyst has the ability to take the sampling point to the sample rather than the other way around. This versatility has opened up many disparate new areas of study, for example, process monitoring, remote identification of hazardous wastes, in vivo medical diagnostics, art and antiquities etc. In this chapter, the design criteria, advantages, and limitations of several different probe head designs are discussed.
Hollow Optical Conduits for Vibrational Spectroscopy
Authors: Doyle Walter M.
Published: September 2006

The sections in this article are

Introduction

Throughput Considerations

Theoretical Basis for Approximating Light Guide Transmission Characteristics

Predicted Light Guide Transmission Characteristics

Light Guide‐Based Spectroscopic Immersion Probes

Summary and Conclusion
Depth Profiling by Microspectroscopy
Authors: Fredericks Peter M.
Published: September 2006

This chapter discusses the use of infrared (IR) and Raman microspectroscopy to investigate the structural variation with depth of solid samples. For IR spectroscopy the common approach is destructive, in that the sample is sectioned and the spectra are collected along the exposed face using transmission, reflection, or attenuated total reflection (ATR) methods. IR microspectroscopy does not lend itself to useful nondestructive approaches, except in the case of the ATR objective, which allows for a small degree of depth profiling by applying internal reflection elements of different refractive indexes leading to a change in the penetration depth. In contrast, Raman microspectroscopy is well suited to depth profiling studies. In the case of destructive approaches, it is similar to IR but has a much higher spatial resolution of about 1 µm compared with a practical limit of 10 µm or more for IR. Because of the confocal nature of many Raman microspectrometers there is also the possibility of resolution along the optical axis so that the signal results from around the focal plane only. If the microspectrometer is operated in confocal mode it is possible, without any sample preparation, for spectra to be collected from within the sample, a process known as “optical slicing”. While there have been some reports demonstrating the efficacy of this approach, there have also been warnings relating to the accuracy of the method. Theoretical ray tracing analysis indicates that inaccuracies exist in the definition of the sampling volume and its depth within the sample.
Gas Chromatography/
F
ourier Transform Infrared Spectroscopy
Authors: Visser Tom
Published: September 2006

The article describes the principles, potentials, and limitations of infrared (IR) spectroscopy as a detector in gas chromatography (GC) in an analytical context. The instrumentation part comprises interfacing of the IR spectrometer and the GC by means of a lightpipe based on a gas‐phase flow cell and two sample storage techniques, that is, matrix isolation and direct deposition which are based on freezing the eluates on a moving substrate. Next to technical aspects, attention is given to instrument optimization in terms of restrictions put by preceding chromatographic requirements. Furthermore, tools for data acquisition, processing, and quantitative and qualitative interpretation are presented. It is concluded that IR can be used as a universal, selective, and specific detector, but a drawback is the lack of sensitivity. However, GC‐IR can supply unique structural information that cannot be obtained from any other method. The latter is illustrated by a number of applications covering environmental analysis, pharmaceuticals and drugs, polymers, food constituents, and biological compounds.
High‐Performance Liquid Chromatography/
F
ourier Transform Infrared Spectroscopy
Authors: Kalasinsky Kathryn S. , Kalasinsky Victor F.
Published: September 2006

The sections in this article are

Introduction

Design Considerations for

HPLC

/

FT
‐
IR

Infrared Spectroscopy

High‐Performance Liquid Chromatography

HPLC

/

FT
‐
IR

Interfaces

Flow‐Cell

HPLC

/

FT
‐
IR

Solvent‐Elimination

HPLC

/

FT
‐
IR

Applications

Proteins

Beverages

Pharmaceutical Samples

Environmental

Polymers –

GPC

/

SEC

Multiple Interfaces

Current Status

Acknowledgments
Thermal Analysis‐IRMethods
Authors: Hellgeth John W.
Published: September 2006

The sections in this article are

Introduction

TAMethods

EGA

DTA

DSC

TGA

STA

IRSpectrometry

EGAwithIRSpectrometry

Evolved Gas Trapping Techniques

EGAUsing a Flow Cell

Display and Manipulation of Spectral Information

EGA‐IRApplications

Application ofEGA‐IRofPVCvia Thermogravimetry

AdvancedEGA‐IRMethods

Condensed PhaseDSC‐IRMethods
Liquefied Gases as Solvents for Vibrational Spectroscopy
Authors: Bulanin Michael O.
Published: September 2006

The sections in this article are

Introduction

Physical and Spectroscopic Properties of Liquefied Gases

Sample Cells

Sample Preparation and Handling

Recording the Spectra
Mid‐Infrared Spectroscopy: Anomalies, Artifacts and Common Errors
Authors: Chalmers John M.
Published: September 2006

Understanding, appreciating and recognizing the influences that anomalies, artifacts and common errors have on the appearance and spectral contrast of a mid‐infrared spectrum is vital if data are to be interpreted and quantified correctly. This article presents examples of some of the common imperfections that may be observed in mid‐infrared spectra, and discusses concisely their origin. It covers the effects of atmospheric intrusion (water vapour and carbon dioxide), and the influences of stray light on the spectra of both liquid and solid samples. It includes a discussion of the superimposition on a spectrum of a sinusoidal waveform, such as ‘channel spectra’ sometimes seen in high‐resolution gas phase spectra or ‘interference fringes’ observed in polymer film transmission spectra. Simple examples of spectra of common contaminants are poly(dimethyl siloxane) – silicone grease/oil‐, phthalate plasticizers from poly(vinyl chloride) (PVC) sources – gloves, pipes ‐, and nitrate from non‐spectroscopic grade KBr. The effects of anomalous dispersion (Christiansen effect) and scatter are illustrated for both a KBr disk and a Nujol
®
mull spectrum; the influence of anomalous dispersion and angle of incidence on attenuated total reflection (ATR) spectra is also discussed, as is the overlay of a specular reflection spectrum on diffuse reflection and transflection spectra. The influence of particle size on spectral contrast for a range of sample presentation methods is illustrated. The origins of saturation effects in photoacoustic FT‐IR spectra, inverted bands in emission spectra, and diffraction effects in FT‐IR microscopy measurements are outlined. Other considerations include choice of single‐beam background, detector non‐linearity, data manipulation, plot software characteristics, instrument linearity, and external reflection mixed‐mode spectra.
Anomalies and Artifacts inRaman Spectroscopy
Authors: Bowie Bryan T. , Chase D. Bruce , Lewis Ian R. , Griffiths Peter R.
Published: September 2006

The sections in this article are

Introduction

Instrumental Effects

Laser Output

Filter Effects

Shifts in the Wavenumber Scale

Aliasing

Multi‐Passing Errors

Detector Effects

Noise Effects

Dark Noise

“Hot Pixels” and Cosmic Rays

Effect of Sample

Introduction

Sample Heating

Fluorescence

Matrix Absorption

Sampling

Introduction

Ambient Lighting

Air

Sample Support Surfaces

Sample Containers – Glass

Sample Movement

Confocal Depth Analysis

Polarization

Acknowledgments
Spectra– Structure Correlations in the Near‐Infrared
Authors: Weyer L.G. , Lo S.‐C.
Published: September 2006

The sections in this article are

Introduction

Hydrocarbons

Aliphatic Hydrocarbons

Aromatics

Olefins

Amines and Amides

Hydroxyls

Alcohols

Phenols

Multiple Hydroxyl Compounds

Carboxylic Acids

Hydrogen Peroxides

Water

Liquid Water, Ice, and Water Vapor

Water in Various Solvents

Water in Other Matrices, Including Glasses

Ionic Species in Water

Carbonyl Compounds

Miscellaneous

Acknowledgments
Spectra–Structure Correlations: Polymer Spectra
Authors: Chalmers John M. , Hannah Robert W. , Mayo Dana W.
Published: September 2006

Features within an infrared (IR) or Raman spectrum recorded from an organic polymer may yield information on chemical structure and composition, isomerism and stereoregularity, conformational order, molecular orientation and state of order.

This article discusses spectra‐structure correlations, both generic (e.g. polyethylene; polybutadiene) and detailed (e.g. high density, low density and linear low density polyethylene;1,4
cis
‐, 1,4‐
trans
and 1,2‐ polybutadiene ), within polymer mid‐infrared and Raman spectra, using as examples for interpretation a range of common polymer types. It considers the influences on polymer and copolymer vibrational spectra of the effects of tacticity, regularity, molecular conformation and orientation, and crystallinity, and discusses copolymer sequence lengths and end group characterisations. The article concludes with examples of spectra recorded from formulated products highlighting the contributions some additives and fillers may make to the observed vibrational spectra of commercial polymer products.
Normal Coordinate Analysis
Authors: Groner Peter
Published: September 2006

The chapter summarizes important concepts from the theory of molecular vibrations of which normal coordinate analysis is a part. Section 2 describes how molecular vibrations or, more precisely, harmonic oscillators are treated in classical mechanics and how normal coordinates are defined. The quantum mechanics of coupled harmonic oscillators, which is based on normal coordinates, is developed in section 3, together with the selection rules for infrared and Raman spectroscopy. It is followed by excursions into some applications of symmetry concepts and into the domain of real molecules where harmonic oscillators are satisfactory approximations at best (anharmonicity and large‐amplitude internal motions). Section 4 introduces the commonly used internal and symmetry coordinates, the transformations between them and the Cartesian and normal coordinates, Wilson's GF method of normal coordinate analysis, and discusses redundant sets of internal coordinates. A short survey of force fields past and present (central, valence, and Urey‐Bradley force fields and force fields from semiempirical and ab initio calculations) is given in section 5. The invariance of internal coordinates, the transformation from internal to Cartesian coordinates, and some aspects of redundant coordinates are detailed in appendices.
Introduction to Factor‐Based Approaches
Authors: Kvalheim Olav M.
Published: September 2006

The sections in this article are

Introduction

Development of Chemometrics

“Making Each Piece of Data Work Twice”

The One‐Variable‐at‐a‐Time Approach in the Presence of Correlation

The One‐Variable‐at‐a‐Time Approach in the Presence of Interaction

Information as a Function of Experimental Strategy

The Latent Variable

Resolution of Multicomponent Profiles

Chemometrics in Society

Chemometrics, Analytical Chemistry and Infometrics

Conclusion

Acknowledgments
Discriminant Analysis
Authors: Fearn Tom
Published: September 2006

The sections in this article are

Introduction

Linear Discriminant Analysis with Two Groups

M
ahalanobis Distance

Extension to Several Groups

Coping with Large Numbers of Spectral Variables

LDA
on Principal Components

Relation between

LDA

and Multiple Regression, and Using Partial Least Squares for Discrimination

Logistic Regression

Validation

Some Limitations, Extensions and Other Approaches

Applications
General Theory of Two‐Dimensional (2
D
) Analysis
Authors: Noda Isao
Published: September 2006

In two‐dimensional (2D) correlation vibrational spectroscopy, a spectrum defined by two independent spectral variables (e.g., wavenumber) is generated by applying a correlation analysis to a series of systematically varying spectra measured under an external physical perturbation. Because of the well‐known specificity of spectral features of infrared (IR) and Raman to chemical constituents of the system, perturbation‐induced variations of spectral signals contain surprisingly rich information about the unique behavior of individual chemical moieties comprising the system. Some of the notable features of 2D correlation spectra are: simplification of complex spectra consisting of many overlapped peaks, enhancement of spectral resolution by spreading peaks over the second dimension, establishment of unambiguous band assignment through correlation of bands selectively coupled by various interaction mechanisms, and determination of the sequential order of events depicted by asynchronous changes in spectral intensities.
Resolution Enhancement Approaches
Authors: Saarinen Pekka E. , Kauppinen Jyrki K.
Published: September 2006

The sections in this article are

Fourier Transform and Impulse Response

Definition and Discretization of Fourier Transform

Continuous Fourier Transform and the Dirac Delta Function

Some Useful Fourier Transform Pairs

The
Discrete Fourier Transform
(

DFT

)

Signal Discretization Effects: Spectral Aliasing and Resolution

Convolution, Impulse Response, and Linear Prediction

Convolution, Impulse Response, and Line Shape

Discrete Convolution

Transfer Function and Causal Impulse Response

Forward and Backward Linear Prediction

Frequency Estimation from the Impulse Response

Eigenanalysis Approach to Frequency Estimation

The Minimum Norm Method

MUSIC

(Multiple Signal Classification)

Resolution Enhancement without Signal Extrapolation

Fourier Self Deconvolution

Derivatives in Resolution Enhancement

Prony's Method

Maximum Entropy Power Spectral Estimator

Resolution Enhancement by Signal Extrapolation

Extrapolation Without Impulse Response: the Minimum Negativity Method

Signal Extrapolation with Impulse Response

Computation of the Impulse Response

The Matrix Methods

The Levinson–Durbin Recursion and Burg's Formula

Theoretical Impulse Response

LOMEP

(
Line Shape Optimized Maximum Entropy Linear Prediction
)

Frequency Tuning Method
Principal Component Regression and Partial Least Squares Modeling
Authors: Hasegawa Takeshi
Published: September 2006

The sections in this article are

Introduction

Data Modeling by Latent Variables

Decomposition of Spectral Data Using Latent Variables

Least Squares Regression by Matrix Algebra

“Partial”CLSto Yield a Principal Component

Principal Component Regressions

Comparison ofCLSandILS

Generate Factors byPCAforILS

Protocols ofPCR

Calculation Steps ofPCRCalibration

Calculation Steps for Concentration Prediction byPCR

Selection of Significant Factors

Analysis of Error

Empirically Defined Method of Error Estimation

Statistical Method for Error Estimation

Selection by Validation

Abstract Spectra and Residuals

Optional Pretreatment

Mean Centering

Scaling

Normalization

Partial Least Squares Regression

PLS2 (GlobalPLS)

PLS2 Calibration

Discussion of thePLS2 Algorithm

Selection of Basis Factors forPLSModeling

PLSPrediction

PLSModeling by Eigenvector Calculation

PLS1 (StandardPLS)

Comparison ofPLS2 withPLS1

Comparison ofPLSwithPCR
Wavelength Selection by Genetic Algorithms
Authors: Berry R. James
Published: September 2006

The sections in this article are

Introduction

Natural Selection

Genetic Algorithms

Reproduction

Crossover

Mutation

Applications of Genetic Algorithms in Vibrational Spectroscopy
Data Transfer
Authors: Davies Antony N.
Published: September 2006

The sections in this article are

Introduction

Data Storage and Archiving

Short‐Term Spectroscopic Data Storage

Regulatory Issues

Individual Spectrometer File Formats

Third‐Party Software House Data Formats

Mid‐ and Long‐Term Spectroscopic Data Storage

The

JCAMP
‐
DX

Standard

Chemistry and the Internet

Chemical
MIME

CML

Conclusions
Qualitative and Quantitative Analysis of Polymers and Rubbers by Vibrational Spectroscopy
Authors: Chalmers John M. , Everall Neil J.
Published: September 2006

This article begins with a short introduction on the range of sample forms, types and properties. This is followed by concise descriptions of the various sampling techniques as they apply to polymer analyses by mid‐infrared and Raman spectroscopy. (The article does not cover near‐infrared spectroscopy). More specific applications sections then follow discussions of qualitative and quantitative analysis and peculiarities associated with polymer mid‐infrared and Raman spectra. These include measurement of molecular orientation, determining end group concentrations and branching, studies of hydrogen bonding and blend miscibility, copolymer composition, polymerisation and cure studies, degradation and oxidation, and determining optical properties and constants. Brief sections are included also on chromatography coupled with FT‐IR, EGA/FT‐IR and TGA/FT‐IR and pyrolysis‐infrared. Discussed also are 2D‐IR, process measurements and microspectroscopy applications. This article is essentially a prelude to the more specialised articles that follow on in this section (Analysis and Characterization of Polymers and Rubbers) in this Handbook.
Measurement of the Solar Properties of Polymers by Vibrational Spectroscopy
Authors: Papini M. , Papini F.
Published: September 2006

The sections in this article are

Introduction

Solar Radiation

Air Mass

Extraterrestrial Solar Radiation on a Horizontal Surface and Attenuation By the Atmosphere: Spectral Properties

Estimation of Clear Sky Radiation

Conclusions

Solar Radiation Measurement

Pyrheliometer

Pyranometer

Diffuse Radiation

Sources of Measurement Error

Detection of Infrared Radiation

Measurement of Solar Radiative Properties

Spectral and Solar Properties

Direct Measurement of Solar Properties

Radiative and Thermal Balance of a Solar Collector

Synthetic Presentation: the Greenhouse Effect

Radiation Transmission through Covers

Collector Top Loss Coefficient

Polymers as Cover Systems

Honeycomb Structures

Polymers as Protective Coatings

Photocells and Conductive Polymers

Conclusions
Determination of Optical and Dielectric Properties of Polymers by Vibrational Spectroscopy
Authors: Smith D.M. , Chughtai A.R.
Published: September 2006

Principles of refraction and extinction of electromagnetic radiation incident upon homogeneous isotropic condensed phases are reviewed. The relation between the complex refractive index,n(ν), and the attenuation constant,k(ν), through the Kramers–Kronig transform is shown as is the relation of these optical constants toɛ, the complex dielectric function. The basis of the determination of the optical constantsnandkas a function of frequency for transparent amorphous polymeric materials by reflection absorption infrared spectroscopy (RAIRS) is illustrated with examples. Also discussed is the effect of absorber concentration on the RAIR spectra. Various methods for the measurement of the optical constants and dielectric function of isotropic polymers included are other reflectance methods, attenuated total reflectance (ATR), transmittance–reflectance, transmission, and ellipsometry. The incipient importance of approaches for determining anisotropic optical constants is noted.
Rheo‐Optical
F
ourier Transform Infrared Spectroscopy of Polymers
Authors: Kalkar A.K. , Siesler H.W. , Zebger I. , Pfeifer F. , Ameri A. , Michel S. , Hoffmann U.
Published: September 2006

This chapter describes the experimental principle and the basic theory of rheo‐optical Fourier transform infrared (FT‐IR) and Fourier transform near‐infrared (FT‐NIR) spectroscopy for the characterization of transient microstructural changes during polymer deformation and stress relaxation. To demonstrate the high potential and the versatility of these techniques, the data obtained from select polymer systems are analyzed and discussed in some detail. In poly(dimethylsiloxane)/polycarbonate (PDMS/PC) block copolymers, for example, depending on the composition and the block lengths, different orientational and recovery phenomena have been observed for the hard (PC) and soft (PDMS) segments. Furthermore, the strain‐induced crystallization of a poly(etherurethaneurea) elastomer system has been successfully monitored during cyclic elongation and recovery. Finally, the versatility of the method has been demonstrated for the characterization of orientation and orientational relaxation in bimodal blends of poly(methylmethacrylate) (PMMA).
Infrared Characterization of Device‐Quality Silicon
Authors: Medernach John W.
Published: September 2006

Vibrational spectroscopy is the major optical characterization technique for semiconductor device‐quality silicon and its associated compounds. The vibrational bands in silicon result from phonon absorption and impurities such as oxygen (O
2
), nitrogen (N
2
) and carbon (C). Information relating to the thickness dependence of the phonon bands and the baseline distortions created by free carriers, roughness, and multiple reflections is provided. A discussion of various new and old techniques used to determine the interstitial O
2
, substitutional C and SiO

x

precipitates is presented. Further discussion includes the methods to determine the thickness of epitaxial silicon and SiGe composite layers, and the more recent developments including numerical simulations and concentration profiles of epitaxial layers. A brief review is given for the measurement techniques and calibrations of oxide, doped oxide and nonoxide layer thickness that is crucial to semiconductor device fabrication. The application of photoluminescence (PL) and Raman methods are also briefly discussed.
Structure and Composition of Glasses and Amorphous Materials by Vibrational Spectroscopy
Authors: Cox J. Neal , Armstrong Jeffrey L.
Published: September 2006

The sections in this article are

Rationale for Analysis

Sample Preparation

Silicate Glass

Fluorinated Silicate Glass

Phosphosilicate Glass and Hydroxyl Contaminants

Amorphous Silicon Carbide

Organic and Organo‐Silicate Spin‐On Glasses

Conclusions
Vibrational Spectroscopy of Food and Food Products
Authors: Li‐Chan E.C.Y. , Ismail A.A. , Sedman J. , van de Voort F.R.
Published: September 2006

Vibrational spectroscopy may be applied to the qualitative and quantitative analysis of complex food systems. Mid infrared (MIR) spectroscopy and Raman spectroscopy are valuable tools for identification and structural characterization of food components and for elucidating structure–function relation of food biopolymers such as proteins. Fourier transform infrared(FT‐IR) spectrometers and chemometrics have broadened the scope of MIR spectroscopy for quality control analysis, but such applications remain generally limited to homogeneous fluid products such as beverages, juices, fats, and oils. In contrast, near infrared (NIR) and FT‐NIR spectroscopy in conjunction with multivariate calibration techniques is becoming increasingly popular in the food industry for rapid and routine analysis of proximate composition of various foods as well as for authentication and detection of adulteration. Increasing application of Raman spectroscopy in food analysis is expected with recent developments in NIR‐FT Raman spectrometers, fibre optic sampling, and confocal Raman microscopy.
Applications of Vibrational Spectroscopy in Brewing
Authors: Meurens Marc , Yan Shou He
Published: September 2006

The purpose of this chapter is to compile the literature concerning the applications of near‐infrared (NIR), mid‐infrared and Raman spectroscopy in the brewing industry. All these three techniques share the advantages that they are rapid, can be noninvasive and allow direct observation of specific molecular species. As for barley, many researchers have used the NIR reflectance on whole grains in malt evaluation. The NIR determination of α/β‐acids and hop storage index in baled hop samples is reported. NIR spectrophotometric methods have been developed for the determination of yeast concentration and activity in beer making. In addition to the applications in the laboratory of quality control, the overview concerns also the applications of infrared and Raman spectroscopy in monitoring of operation and process control at the essential steps of mashing and wort fermentation in brewery. The results obtained with a short wave NIR spectrophotometer are presented in comparison with long wave NIR spectrophotometers.
Near‐Infrared Spectroscopy of Cereals
Authors: Williams Phil
Published: September 2006

This chapter introduces cereal grains and their role in the industry, and in life. Their basic composition is reviewed together with their functionality (the capability of a commodity to produce consumer‐acceptable end‐products). By far the most important sphere of vibrational spectroscopy as it applies to cereals is near‐infrared spectroscopy (NIRS). The particular characteristics associated with composition and functionality of individual cereals and other grains for which analysis by NIRS is applicable are outlined. Application of NIRS to industrial aspects of cereals is summarized, including grading and pricing of grains, together with the degree of success achieved in application of NIRS to factors pertinent to the grading and the plant‐breeding selection process. Features of NIR spectroscopy that are peculiar to cereals and other grains are described. The application of NIRS to these materials is complicated by interactions among constituents, which strongly influence wavelength selection and instrument calibration. Spectra of select commodities are used to illustrate some of the anomalies that can occur in the application of NIRS to grains. These include apparent suppression of absorption bands in the natural or “raw” spectra of whole grains, although the bands are distinct when the grains are ground to a meal. Steps in the development of calibration models, and the approaches to their interpretation by statistical processes are explained.
Vibrational Spectroscopy to the Analysis and Study of Forages
Authors: Barton Franklin E. , Himmelsbach David S.
Published: September 2006

The beginnings of the use of modern vibrational spectroscopy in agriculture were with near infrared spectroscopy (NIRS) and the early definitive studies were conducted on forages. These beginnings can be traced by the work accomplished by Agricultural Research Service's National Near Infrared Research Project, which began in 1978 and culminated in 1988 with the issue of the first Association of Official Analytical Chemists (AOAC), International Official Method for protein and Acid Detergent Fiber by NIR. NIRS models were developed for the analysis of crude protein, moisture/dry matter, permanganate lignin, acid detergent fiber, neutral detergent fiber, acid detergent lignin, and in vitro and in vivo digestibility. This article discusses the requirements of an analytical method as it applies to chemometric methods and NIRS, in particular, by answering three questions and those requirements, which differ for the establishment of “Official Methods”. Other vibrational spectroscopies as applied to forage analysis are discussed in brief.
Process Monitoring by Mid‐ and Near‐Infrared Fourier Transform Spectroscopy
Authors: Tate J.D. , Chauvel Paul , Guenard Robert D. , Harner Rich
Published: September 2006

The sections in this article are

Introduction – General Requirements

Contrast to Laboratory Instruments

Operating Performance

Signal‐to‐Noise Ratio

Instrument‐to‐Instrument Variability

Long‐Term Drift

Mean‐Time‐to‐Failure and Mean‐Time‐to‐Repair

Calibration Transfer

Design Considerations

Analyzer Layout

Modularity

Backward/Forward Compatibility

Environmental Influence

User Interface

Remote Connectivity

I
/
O

to Operations

Troubleshooting and Diagnostics

Power Requirements

Reliability

Maintenance and Repair

Safety‐Regulatory Compliance

Electrical Classification

American Society of Mechanical Engineers Probe Certification

Documentation

Training

On‐Line Quantitative Procedures

FT
‐
IR

Transmission Cells

Attenuated Total Reflection

Sample Systems and Analyzer Shelters

Detectors

FT
‐
NIR

Probes

Probe Installations

Fibers and Connectors

Fibers

Connectors

Multiplexers

Sample Cells

Detectors

Applications

When is the Use of
FT
‐
IR
or

FT
‐
NIR

Appropriate for On‐Line Analysis?

Implementation

Examples of Applications of
FT
‐
IR
and

FT
‐
NIR

Impurities in Anhydrous
HCl
by
FT
‐
IR

Analysis of Caustic Soda by

FT
‐
NIR

Attempted Analysis of Aqueous
HCl
/Aniline Solutions by

FT
‐
NIR
FT
‐
IR
Measurements of Atmospheric Trace Gases and their Fluxes
Authors: Griffith David W.T.
Published: September 2006

Changing atmospheric composition is the primary driving force behind most aspects global climate change. In this chapter, we focus on field‐portable FTIR measurement techniques for four of the most abundant and important trace gases – carbon dioxide (CO
2
), methane (CH
4
), nitrous oxide (N
2
O) and carbon monoxide (CO). There are two themes: applications of FTIR spectrometry for high precision in situ measurements of CO
2
, CH
4
, N
2
O and CO in relatively clean air, and remote sensing of atmospheric composition by ground‐based high resolution solar FTIR spectroscopy. Portable instruments and methods suited to high precision field measurements of trace gas composition are described, followed by several approaches to the measurement of rates of emission and exchange of these trace gases with sources and sinks at the earth’s surface. Ground based remote sensing by high resolution solar absorption spectroscopy is also described.
Vibrational Spectroscopy in the Paint Industry
Authors: Carr Christopher
Published: September 2006

The sections in this article are

Introduction

Chemical Analysis

Bulk Composition

Depth Profiling

Polymer Synthesis

Film Formation and Curing

Photodegradation

Introduction

Vibrational Spectroscopy and Durabilty Testing

Effect of Pigments

Conclusion

The Future
Vibrational Spectroscopy of Colors, Dyes and Pigments
Authors: Dent Geoffrey
Published: September 2006

The chapter illustrates specific applications of vibrational spectroscopy to colour analysis and colour probes. These include the effects of sample preparation variations for infrared spectroscopy on the colour properties and comparisons of differing laser techniques in Raman spectroscopy relative to the measurement required. A wide range of colour from prehistoric pigments to modern electronic dyes is considered. Several chemical groups, common in colour chemistry, are identified and comments made on the interpretation of the bands. Examples of reactions following tautomerism, hydration, and polymorphism are given. The use of Raman techniques, particularly surface enhanced resonance Raman spectroscopy (SERRS), as colour probes is highlighted and examples of the electronic uses of dyes are given. Brief mention is made of on/at line plant measurements and the spectroscopy of dyes in biological applications.
Vibrational Spectroscopy in the Study of Oxide (Excluding Zeolites) and Sulfide Catalysts
Authors: Payen E. , Grimblot J. , Lavalley J.C. , Daturi M. , Maugé F.
Published: September 2006

The sections in this article are

Introduction

Infrared Spectroscopy

IR

Characterization of Surface Properties of Metal Oxides

Information Deriving from the Activated Oxide Spectra

Lattice Vibrations

Surface Oxide Sites

Identification of Main Impurities in Metal Oxides

Electronic Transitions

Hydroxyl Groups

Information Deriving from Probe Adsorption

Acidity

Basicity

Cationic and Redox Sites: Use of Methanol as Probe for Local Arrangement and Oxidation State Determination of Surface Cationic Sites

IR

Characterization of Oxide and Sulfide Supported Catalysts

Information Deriving from the Spectrum of the Activated Catalyst

Information Deriving from Probe Molecule Adsorption

CUS

Characterization of the Sulfided Phase

B
rønsted Acid Site Characterization of the Sulfided Phase

Site Transformation in the Presence of
H
2

Surface Characterization and Catalysis

Conclusion

R
aman Spectroscopy

General Considerations

Bulk Oxide Catalysts

Supports

Supported Oxides

Nature of the Supported Oxide

Chemical Processes Involved During Catalyst Synthesis

Adsorption of Probe Molecules

Surface
B
rønsted and Lewis Acid Sites

Adsorption of Molecules Acting as Reagents

Active Phase: Genesis and Characterization

Genesis of the Hydrodesulfurization Active Phase

Sulfided Catalyst

Catalyst Reactivity

Conclusion

Concluding Remarks and Outlook
Vibrational Spectroscopy of Zeolites
Authors: Zecchina Adriano , Spoto Giuseppe , Bordiga Silvia
Published: September 2006

The sections in this article are

The Structure of Zeolites and Zeotype Materials

The Vibrational Spectra of Zeolites and of Zeolitic Materials: General Considerations

Framework Modes

IR

Modes Associated with the
B
rØnsted Groups and their Modifications upon Interaction with Adsorbates

The Spectrum of Free
B
rønsted Groups

Modifications Induced by Adsorbates

The Vibrational Spectra of Molecules Adsorbed on Charge Balancing Cations

Cation and Cation‐Sensitive Modes: Perturbations Induced by Adsorption

Vibrational Spectra of Molecules Adsorbed on Strong Lewis Centers

Vibrational Spectroscopies in Reaction Dynamics Studies on Zeolites
Vibrational Spectroscopy of Model Systems for Adsorbed Species on Finely Divided Metal Catalysts
Authors: De La Cruz Carlos
Published: September 2006

The sections in this article are

Introduction

Vibrational Spectroscopic Techniques for the Study of Adsorbed Species on Single‐Crystal Metal Surfaces

Vibrational Energy Loss Spectroscopy

Reflection–Absorption Infrared Spectroscopy

Infrared–Visible Sum Frequency Generation Spectroscopy

Inelastic Electron Tunneling Spectroscopy

Raman Spectroscopy

Interpretation of Vibrational Spectra of Adsorbed Species on Single‐Crystal Metal Surfaces

Symmetry Considerations

Site Symmetries on Single‐Crystal Metal Surfaces

Symmetry and Vibrational Properties of the Overall Surface Species

Absorption Mechanisms and Selection Rules

Dipolar Mechanism

Impact Mechanism

Polarizability Mechanism

Resonance Mechanism

Group Frequency and Intensity Analysis of ModelC2‐Hydrocarbon Systems

A Group Frequency/Intensity Correlation Chart forC2‐Hydrocarbon Ligands in Metal Complexes and Clusters

An Exploration of theCCInternuclear Distance/CCBond‐Stretching Wavenumber (dCC/νCC) Relationship

Worked Example

π‐C2H4Complexes

Di‐σ‐C2H4and di‐σ*‐C2H4Complexes

Ethylidyne Species

Ethyl Surface Group

Conclusion

Acknowledgments
Vibrational Spectroscopy of Liquid Crystals
Authors: Czarnecki Mirosław A.
Published: September 2006

This contribution presents some applications of static and time‐resolved vibrational spectroscopy to various liquid crystalline systems including low‐molecular‐weight nematics, ferroelectric and antiferroelectric liquid crystals (LCs), polymeric LCs, guest–host systems, and polymer‐dispersed LCs. Special attention has been paid to an application of time‐resolved Fourier transform infrared (FT‐IR) and Raman spectroscopy to study the electric‐field induced reorientation mechanism of LCs on a molecular level by monitoring the behavior of different functional groups. Most of the experimental results suggest that the low‐molecular‐weight LCs reorient as rigid rods. Regarding the polymeric LCs, only the mesogen and a small part of the spacer participate in the switching, while the rest of the spacer and the main chain do not reorient. An understanding of these molecular motions may lead to the development of better‐performing LC systems.