A Review of the State of the Art,Limitations, and Perspectives of Infrared Spectroscopy for the Analysis of Wine Grapes,Must, and Grapevine Tissue

Abstract

As a fast and easy-to-operate technique, infrared (IR) spectroscopy has gained wide industrial acceptance for routine wine analysis. Considering the continuing improvements in hardware and software design and the analytical requirements of real-time or multiparametric analysis by the modern grape and wine industry, it is anticipated that in the near future IR spectroscopy will progressively become a routine method for process monitoring and process control in different stages of grape and wine production. This review highlights recent developments and applications of IR spectroscopy (near- and mid-infrared) to measure compositional parameters in wine grapes, grape juice, and grapevine tissues (e.g., leaves, stems, grapevine wood). In addition, some critical aspects and limitations in instrument availability, type of application, and overall understanding of the technology, which can be barriers for adoption of IR technologies by the grape and wine industry, will be discussed.     

FT-IR,EDXRF and Gamma-Isotopic Analyses of Ashes from Coal Fired Power Plants of Turkey

Abstract

Nine ash samples collected from five coal fired power plants of Turkey have been analysed by FT-IR, EDXRF and γ -isotopic analyses methods. IR spectroscopy together with mineralogical analysis is found to be a useful method for investigating the inorganic chemical composition of the ashes which is an inherently variable material due to differences in the inorganic chemical composition of the source coal and in ash collection. Gamma-isotopic analysis indicated that all samples contained Ra-226, U-238 and Th-232. On the other hand Cs-137 (16.3 pCi/g) was found only in the ash sample collected from the Yata?an coal fired power plant. An ash sample taken from the electro-filter of the Ambarli, a fuel oil fired-power plant of Turkey, was also analysed for comparision and found that it contained least amount of U-238.     

Quality Control of Honey Using Infrared Spectroscopy: A Review

Abstract

Honey is a carbohydrate-rich syrup and viscous fluid produced by honeybees (Apis mellifera) from the nectar of flowers that, by definition, does not include any other substances. Honey is produced primarily from floral nectars, and fructose and glucose are the major components. Overall, the chemical composition of honey varies depending on plant source, season, production methods, and storage conditions. Analytical methods applied to honey generally deal with different topics such as determination of botanical or geographical origin, quality control according to the current standards, and detection of adulteration or residues. Traditional chemical composition analysis and physical properties assessment are routinely performed in commercial trading of honey using time-consuming analytical methods that require considerable sample preparation and analytical skills. Spectroscopic techniques in the infrared (IR) wavelength region of the electromagnetic spectrum have been used in the food industry to monitor and evaluate the composition of foods and are becoming one of the most attractive and commonly used methods of analysis. This review discusses the use, with advantages and limitations, of IR spectroscopy technologies to evaluate and monitor the composition of honey.     

A Review of Applications and Experimental Improvements Related to Diode Laser Atomic Spectroscopy

Abstract

This article attempts to review the major advancements made in the past 12 years, since 1993, in the field of diode laser atomic spectroscopy. The discussion covers experimental improvements (e.g., wavelength stabilization, frequency upconversion, enhancement of tuning characteristics, spectral bandwidth using external cavities, etc.), diagnostic applications in various atomizers, as well as analytical applications (e.g., absorption, fluorescence, and ionization spectroscopy; element‐selective detectors for chromatography; etc.). With potential new users of these methods in mind, a detailed overview of the properties relevant to atomic spectroscopy of commercial diode lasers is also given.     

New insights into plant cell walls by vibrational microspectroscopy

Vibrational spectroscopy provides non-destructively the molecular fingerprint of plant cells in the native state. In combination with microscopy, the chemical composition can be followed in context with the microstructure, and due to the non-destructive application, in-situ studies of changes during, e.g., degradation or mechanical load are possible. The two complementary vibrational microspectroscopic approaches, Fourier-Transform Infrared (FT-IR) Microspectroscopy and Confocal Raman spectroscopy, are based on different physical principles and the resulting different drawbacks and advantages in plant applications are reviewed. Examples for FT-IR and Raman microscopy applications on plant cell walls, including imaging as well as in-situ studies, are shown to have high potential to get a deeper understanding of structure–function relationships as well as biological processes and technical treatments. Both probe numerous different molecular vibrations of all components at once and thus result in spectra with many overlapping bands, a challenge for assignment and interpretation. With the help of multivariate unmixing methods (e.g., vertex components analysis), the most pure components can be revealed and their distribution mapped, even tiny layers and structures (250 nm). Instrumental as well as data analysis progresses make both microspectroscopic methods more and more promising tools in plant cell wall research.     

Vibrational Spectroscopy in Clinical Analysis

Abstract: Vibrational spectroscopy includes several different techniques, the most important of which are mid-infrared (IR), near-IR, and Raman spectroscopy. Raman and mid-IR spectroscopy are complementary techniques and usually both are required to completely measure the vibrational modes of a molecule. Vibrational spectrometry covers a series of well-established analytical methodologies suitable to be employed for both qualitative and quantitative purposes. In the first part of this review, we will focus on theoretical aspects related to vibrational techniques; in the second part, the most important papers, published during the period 2005–2014, related to clinical analysis performed with vibrational spectroscopy techniques will be critically discussed.     

Application of Infrared Photoacoustic Spectroscopy in Soil Analysis

Abstract

Soil analysis has become routine work for soil management and crop production. However, laboratory analysis–based determination of soil properties is expensive and time consuming, which is not suitable for precision agriculture. Infrared spectroscopy (IR) appears as an alternative and fast technique to measure soil properties and has had wide application; in particular, a new method called infrared photoacoustic spectroscopy (FTIR-PAS) has been applied in soil analysis. The soil infrared photoacoustic spectrum is more convenient to record; the spectra contain more useful information versus conventional reflectance spectroscopy, and it appears promising for identification of soil types and measure soil properties. The step-scan function of FTIR-PAS makes it possible to explore the soil microstructure in situ; furthermore, more sensible photoacoustic cells (PA), such as a quartz-enhanced PA cell, will make FTIR-PAS a strong tool for the study of soil science. The application of infrared photoacoutic spectroscopy in soil analysis is largely dependent on spectra pretreatment and chemometrics methods due to strong interferences, and more mathematical tools models will benefit or optimize the prediction performance. To make full use of soil infrared spectra, soil spectra library construction is required in the future, which will play an important role in the application of soil analysis.     

Plant elemental composition and portable X‐ray fluorescence (pXRF) spectroscopy: quantification under different analytical parameters

Emergence of portable X‐ray fluorescence (pXRF) systems presents new opportunities for rapid, low‐cost plant analysis, both as a lab system and in situ system. Numerous studies have extolled the virtues of using pXRF for a wide range of plant applications, however, for many such applications, there is need for further assessment with regards to analytical parameters for plant analysis. While pXRF is a potential powerful research tool for elemental composition analysis, its successful use in plant analysis is made more likely by having an understanding of X‐ray physics, calibration process, and ability to test a variety of homogenous and well‐characterized materials for developing a matrix‐specific calibration. Because potential pXRF users may often underestimate the complexity of proper analysis, this study aims at providing a technical background for plant analysis using pXRF. The focus is on elemental quantification under different analytical parameters and different methods of sample presentation: direct surface contact under vacuum, placement in a sample cup with prolene as a seal, and without the aid of a vacuum. Direct analysis on the surface of a pXRF provided highest sensitivity and accuracy (R² > 0.90) for light elements (Mg to P). Sulfur, K, and Ca can be reliably measured without the aid of a vacuum (R² > 0.99, 0.97, and 0.93 respectively), although lower detection limits may be compromised. pXRF instruments provide plant data of sufficient accuracy for many applications and will reduce the overall time and budget compared with the use of conventional techniques. Sensitivity and accuracy are dependent on the instrument's settings, make, and model. © 2015 The Authors. X‐Ray Spectrometry published by John Wiley & Sons, Ltd.     

Infrared spectroscopy combined with imaging: A new developing analytical tool in health and plant science

Modern infrared (IR) spectroscopy and imaging has a wide range of applications in health and plant sciences. Initially, it was extensively used for the study of proteins, nucleotides, lipids and carbohydrates. With time, its use has extended to disease assessment to discriminate healthy and diseased samples on the basis of chemical changes. The application of an advanced focal plane array detector, which is able to scan a large area of samples in a short time, helps in investigating specific changes that could be correlated with different environmental stresses. An IR microscope connected with a synchrotron light source further enhances the lateral spatial resolution at diffraction limit because of the compact beam size. For example, synchrotron-based IR spectroscopy imaging in combination with multivariate statistical analysis has been proven to be a powerful non-destructive analytical tool to probe changes in plant cell wall composition/structure in response to biological processes and environmental stresses. New development of nano-Fourier transform infrared spectroscopy (FTIR) combined with scattering type scanning near-field optical microscopy breaks the diffraction limitation, which opens the new area of applications. This review focuses on a new area of diagnostic research as well as development of IR spectroscopy and imaging for biological specimens including compositional changes in plant cell wall.     

The infrared spectra of solid solutions of some iron and chromium oxides

Oxides Fe_2–x Cr _x O₃ (corundum-type) and Fe_3–y ,Cr _y O₄ (spinel-type) were studied by transmission IR spectroscopy. The wavenumbers corresponding to characteristic absorption maxima depend linearly on the composition of both types of solid solutions, i.e. onx andy. The results show that IR spectroscopy can contribute to the analysis of solid solutions of iron and chromium oxides and of the oxidation products of Fe-Cr alloys.The authors are indebted to Ing. P. Holba for the preparation of synthetic oxide samples. The cooperation of Yu. Borodkin and I. Zuika (Riga) who made the measurements in the far IR region is gratefully acknowledged.     

A planetary environment and analysis chamber (PEACh) for coordinated Raman–LIBS–IR measurements under planetary surface environmental conditions

A planetary environment and analysis chamber (PEACh) has been developed at Washington University in St. Louis, in order to perform in situ multiple spectroscopic measurements on geological samples under relevant planetary environmental conditions and to support future planetary missions, with particular interest on Mars. The pressure in the chamber can range from ambient to 3 × 10⁻² mbar. The simulated atmospheric composition and pressure are regulated via a combination of needle and ball valves connecting the chamber with containers filled with premixed gas. The temperature of the samples can be controlled in a range from ambient to − 100 °C. The in situ analytical techniques implemented (and to be implemented) are laser Raman spectroscopy, laser‐induced breakdown spectroscopy (LIBS), near‐IR reflectance spectroscopy, mid‐IR attenuated total reflectance spectroscopy, and microscopic imaging. The coordinated spectroscopic sensing on the same geological sample under well‐controlled atmospheric conditions in the PEACh establishes a way to link the results from the laboratory experiments to the spectral data obtained by landed and orbital planetary exploration missions, which will facilitate understanding the surface processes by which mineral phases occur and their association with atmospheric changes. Copyright © 2011 John Wiley & Sons, Ltd.     

New Developments and Applications of Handheld Raman,Mid-Infrared,and Near-Infrared Spectrometers

Abstract: Recently, miniaturization of Raman, mid-infrared (IR), and near-infrared (NIR) spectrometers has made substantial progress. Though mid-infrared systems are based exclusively on attenuated total reflection (ATR) measurements, near-infrared spectrometers operate in the diffuse reflection or transmission mode. The reduction in size, however, must not be accompanied by deterioration in measurement performance, and portable instrumentation will only have a real impact on quality and process control if Raman, IR, and NIR spectra of comparable quality to laboratory spectrometers can be obtained.

In the present communication, a short overview on the building principles of novel handheld systems will be provided and the results of qualitative and quantitative analyses of selected liquid and solid sample systems obtained with these Raman, Fourier transform infrared (FTIR), and NIR spectrometers will be evaluated in terms of their comparability with laboratory instruments and their suitability for on-site and field measurements.     

An Overview of 195Pt Nuclear Magnetic Resonance Spectroscopy

Abstract

This brief, non‐exhaustive review describes some basic theoretical aspects of ¹⁹⁵Pt nuclear magnetic resonance spectroscopy and also the empirical approach used by the researchers in the field. The different factors which influence the chemical shifts are discussed. The couplings constants between ¹⁹⁵Pt and other isotopes, which have a spin of 1/2 (such as, ¹H and ¹³C) bring further important information on the structures of Pt compounds. Recently, ¹⁹⁵Pt‐NMR spectroscopy in the liquid state has been used successfully in many research fields, e.g., the determination of enantiomeric composition and absolute configuration, in the area of biosensors and biomarkers, in cluster chemistry, in cancer research and in kinetic studies. While liquid‐state ¹⁹⁵Pt‐NMR spectroscopy encompasses a wide range of areas, the parallel solid‐state technique has only been employed over the past few years, mainly in studies of heterogeneous catalysis and is more industrially oriented.     

Chemical Composition of Porous Silicon Formed in Aqueous and Aqueous-Alcoholic Electrolytes, According to the IR Spectroscopy Data

The chemical composition of the surface of porous silicon synthesized on weakly doped silicon of the n type of conductivity (KÉF-20) with the crystallographic orientation (100) (100) in aqueous and aqueous-alcoholic electrolytes with different HF concentrations has been analyzed by IR spectroscopy.     

Open dynamic behaviour of financial markets

Open dynamic behaviour of financial markets with internal interactions between agents and with external “fields” from other systems are investigated using the approach of Grossman and Stiglitz for inefficient markets, and Keynes for interference of the market using physics of finance (referred to hereafter as phynance). The simulation results indicate that the NYSE data analyzed in Plerou, V. et al., Nature 421, 130 (2003) can be fitted by an equation of order parameter Φ and local deviation R of type: -(R+0.03) Φ+ 0.6 Φ³ + 0.02 = 0, which is shown to be in remarkable agreement with Plerou's data.     

光腔衰荡光谱技术测定大气水汽稳定同位素校正方法研究

几乎所有小的气相分子（如H₂O,CO₂等）均具有独特的近红外吸收光谱,在负压条件下,每种微小的气相分子都拥有一对一的特征光谱线,基于这一原理人们开始使用激光光谱（IRIS）技术来准确分析气体样品中的同位素组成。该方法克服了传统同位素比质谱（isotope ratio mass spectrometry, IRMS）方法的局限性,已经成为公认的高精度、高灵敏度和高准确度的痕量气体检测方法。以大气水汽稳定同位素研究为例,大气水汽稳定同位素组成对水汽源区及其通道上的输送过程等水循环研究有着重要的指示意义。激光光谱技术使得大气水汽氢氧稳定同位素（δ18O和δD）野外原位连续高分辨率观测成为可能。但是,其观测精度和准确度受仪器运作特点、不同浓度大气水汽对特定光谱吸收性的敏感性差异等因素的影响,通常观测结果具有明显的非线性响应问题。因此,有必要对仪器观测过程中出现的各种偏差进行校正,但现阶段许多用户对新观测技术的国际校正方法尚不清楚。因此,基于波长扫描-光腔衰荡光谱（WS-CRDS）技术的大气水汽同位素观测系统（Picarro L2120-i）,通过可调谐二极管激光器（Tunable Diode Laser, TDL）发射可被待测气体分子所吸收的不同波长的激光,测量不同波长下的衰荡时间（即有样品吸收的衰荡时间）;TDL发射不能被待测气体吸收的不同波长的激光,测量每个波长下的衰荡时间（相当于无样品吸收的衰荡时间）。通过分析有无样品吸收的衰荡时间差,高精度计算待测气体的分子浓度,进而计算水汽稳定同位素组成。从记忆效应、漂移效应、浓度效应等方面,系统建立了一套准确可靠的大气水汽稳定同位素观测流程与校正方法,为正在使用或将要使用此类设备的研究人员提供参考,以获得高精度和高可靠性的大气水汽稳定同位素观测数据。     

The Difference Between the Standard and The Lorentz Transformations of the Electric and the Magnetic Fields

In this paper it is shown by using the Clifford algebra formalism that the usual Lorentz transformations of the three-dimensional (3D) vectors of the electric and magnetic fields E and B (which will be named as standard transformations (ST)) are different than the Lorentz transformations (LT) of well-defined quantities from the 4D spacetime. This difference between the ST and the LT is obtained regardless of the used algebraic objects (1-vectors or bivectors) for the representation of the electric and magnetic fields in the usual observer dependent decompositions of F. The LT correctly transform the whole 4D quantity, e.g., E_f : F · γ₀, whereas the ST are the result of the application of the LT only to the part of E_f, i.e., to F, but leaving γ₀ unchanged. The new decompositions of F in terms of 4D quantities that are defined without reference frames, i.e., the absolute quantities, are introduced and discussed. It is shown that the LT of the 4D quantities representing electric and magnetic fields correctly describe the motional electromotive force (emf) for all relatively moving inertial observers, whereas it is not the case with the ST of the 3D E and B.     

Can an IR Diode Laser Spectrometer be Used for the Determination of Natural Isotope Ratios in Biological Samples?

Abstract

An IR diode laser spectrometer can detect the enrichment of stable isotopes (¹³C [1] and ¹⁵N[2]) in tracer studies. However our system cannot detect differences of the natural abundances of these isotopes. This problem is not a principal limitation of the IR diode laser spectroscopy, but is inherent to our standard system. A new isotope ratio IR diode laser spectrometer has an accuracy high enough for most biological applications. Some advantages like flexibility in measuring different isotopes, insensitivity against other gases in the sample and price are correlated to this system.     

A Review of Online Real-Time Process Analyses of Melt-State Polymer Using the Near-Infrared Spectroscopy and Chemometrics

Abstract

This review describes the online process monitoring of the melt-state polymer by near-infrared (NIR) spectroscopy and chemometrics. The spectra of linear low-density polyethylene (LLDPE), random polypropylene (RPP), block polypropylene (BPP), and ethylene-vinylacetate (EVA) copolymer in melt states measured by an online monitoring system with a Fourier transform near-infrared spectrometer are discussed. The calibration models for the density of LLDPE, the content of ethylene copolymers in RPP and BPP, and vinylacetate concentration (VA) in EVA copolymers using partial least squares regression are reported. The continuous monitoring of the LLDPE density at the real plant is described as an example of online monitoring using NIR spectroscopy and chemometrics. For the precise prediction of VA in EVA, a combination method using regression and discrimination was inducted. Three compensation methods for the effect of the temperature change in the RPP and BPP samples are shown. Conventional calibration transfer methods are introduced, and a practical calibration transfer method using two samples and its performance are reported using BPP and RPP spectra. Moreover, the possibility of a calibration correction method using one sample for the realization of long-term traceability is indicated by the example of the relocation.