Abstract
The instrumentation, methods and applications of near-infrared spectroscopy has advanced remarkably in the last decade, in which near-infrared spectroscopy has successfully progressed at multiple directions and faced new challenges. Thus, gaps inevitably appeared in the coverage provided by renowned and handy cornerstone textbooks focused on near-infrared spectroscopy that were published in the past. A demand grew in near-infrared spectroscopy community for a new state-of-the-art textbook. With aim to satisfy such need, a go-to-book for background theory, applications and tutorial “Near-Infrared Spectroscopy Theory, Spectral Analysis, Instrumentation, and Applications” was prepared. That full-scale project, edited by Yukihiro Ozaki, Christian Huck, Satoru Tsuchikawa and Søren B. Engelsen, comprises of 23 chapters contributed by scholars and practitioners pushing the frontier of near-infrared spectroscopy. The chapters scope on newly opened pathways, major breakthroughs in basic science and applications as well as revisit several other topics. The sourcebook is intended for a wide range of readers from graduate students to scientists and engineers in both academia and industry. In this article, we sketch the main features of the newly released sourcebook with aim to help the community members in deciding whether this book should find its place in their library.
About the book
Near-infrared (NIR) spectroscopy appears as a mature, well-established technique comfortably settled in a variety of applications. Nonetheless, it continues to demonstrate remarkable advancements in the technology and data analytical approaches. Those breakthroughs revolutionized many of the existing applications and paved the way for developing entirely new roles of NIR spectroscopy.
With such rapid evolvement, the knowledge contained in the available to date fundamental handbooks has inevitably become incomplete. A demand for a new state-of-the-art textbook on NIR spectroscopy has been expressed in the community. In response, the concept of a new handbook emerged. “Near-Infrared Spectroscopy Theory, Spectral Analysis, Instrumentation, and Applications”, edited by Yukihiro Ozaki (Kwansei Gakuin University, Japan), Christian Huck (University of Innsbruck, Austria), Satoru Tsuchikawa (Nagoya University, Japan) and Søren B. Engelsen (University of Copenhagen, Denmark), collects comprehensive and updated information prepared by the scholars and professionals active in their respective fields. The book is now available for purchase from Springer Nature in both printed and electronic versions (https://www.springer.com/gp/book/9789811586477). 1
The concept of the book is to provide a general sourcebook for use by wide audience of newcomers as well as experts interested in the fascinating world of NIR spectroscopy (Figure 1). In a total number of 593 pages comprising 23 chapters, augmented by 86 black-and-white illustrations and 196 illustrations in colour, the sourcebook aims to provide readily available and balanced information on the key aspects related to the principles, technologies and applications of NIR spectroscopy in modern science and technology (Figure 2).
Graphical abstract.
The front cover of the recently released comprehensive sourcebook for NIR spectroscopy “Near-Infrared Spectroscopy Theory, Spectral Analysis, Instrumentation, and Applications”.
Further aim of the sourcebook is to lay a bridge between the various scientific and professional communities interested in NIR spectroscopy and using it for their diverse needs. It is the intention of the editors and authors of this contribution to provide a handbook for molecular spectroscopists, researchers and engineers active in various fields. With a considerable attention given to the description of basic knowledge indispensable for learning how to use NIR spectroscopy as a potent tool, that contribution is also aimed to serve as an accessible textbook for graduate science and engineering students.
Overview of the book’s content
The book comprises a total of 23 chapters divided into four parts. The Part I (containing chapters 1 to 3) introduces the reader to the content of the book and covers the fundamentals underlying NIR spectroscopy. The Part II (chapters 4 to 7) focuses on the techniques of spectral analysis and data treatment, the essential elements in most applications. The Part III (chapters 8 to 12) of the book discusses the principles of instrumentation, while the Part IV (chapters 13 to 23) covers the major fields of application of NIR spectroscopy in science and industry.
Chapter 1 – Introduction
In the opening chapter, Yukihiro Ozaki and Christian Huck introduce the reader to NIR spectroscopy, an immensely exciting discipline. 2 Starting with the whereabouts of the discovery of NIR region of electromagnetic radiation, through the fundamentals underlying NIR spectroscopy and the astonishing history of its evolvement to the point of state-of-the-art tool of modern analytical chemistry, the reader is acquainted with the essentials of the eponymous technique.
Chapter 2 – Principles and characteristics of NIR spectroscopy
In Chapter 2, Yukihiro Ozaki and Yusuke Morisawa discuss the characteristics of NIR spectroscopy with special attention given to the unique advantages of this technique directly responsible for its practical value. 3 Essential features such as the principles molecular vibrations, group frequencies and the origins of NIR bands, and the resulting distinctiveness of NIR spectra are explained on the ground of quantum chemistry and various exemplary NIR spectra. The strengths of this technique in relation to other kinds of spectroscopy and the resulting versatility of NIR spectroscopy as the tool at disposal of modern science and technology are evaluated.
Chapter 3 – Theoretical models of light scattering and absorption
Chapter 3 by Kevin D Dahm and Donald J Dahm deals in detail with the phenomenon critical for any optical spectroscopy, however particularly indispensable for the applications of NIR spectroscopy, namely the interaction of light with matter. 4 The physical behaviour of light interacting with matter is dissected, while the major attention is given to the theoretical approaches to modelling that phenomenon, where e.g. the intricate phenomena resulting from the interaction with a complex sample have a profound significance for analytical applications of NIR spectroscopy.
Chapter 4 – Spectral analysis in the NIR spectroscopy
Spectral analysis, the topic of key significance for practical applications, is dissected by Yukihiro Ozaki, Shigeaki Morita and Yusuke Morisawa in Chapter 4. 5 The reader is familiarized with the fundamentals of spectra pretreatment methods, e.g. differentiation, baseline correction, noise reduction or normalization algorithms, which are the commonly applied methods improving the suitability of the measured spectra to the subsequent analysis.
Chapter 5 – Introduction to quantum vibrational spectroscopy
Practically feasible theoretical prediction of NIR spectra has become recently available. Chapter 5 by Krzysztof B Beć, Justyna Grabska and Thomas S Hofer presents the background to the anharmonic quantum chemical approaches that are indispensable for that purpose. 6 The chapter gives the reader a good understanding of the underlying principles, beginning with the general framework of quantum chemistry for the description of molecular vibrations, the harmonic approximation and its role as the preliminary step for various anharmonic approaches. Various available routes to anharmonic treatment of molecular vibrations are presented, and their applicability to NIR spectroscopy is evaluated based on several examples.
Chapter 6 – Two-dimensional correlation spectroscopy
Mirosław A Czarnecki and Shigeaki Morita familiarize the reader with two-dimensional (2D) correlations spectroscopy. 7 This powerful tool is particularly potent when applied to complex and difficult in direct interpretation NIR spectra, as it elucidates correlations between the peaks in a selective way and yields resolution enhancement. This technique gives access to useful information on the dynamics of spectral changes and enables more reliable band assignments, offering unique capabilities in NIR spectroscopy.
Chapter 7 – NIR data exploration and regression by chemometrics: A primer
Multivariate data analysis, i.e. chemometrics, is an extremely important tool in NIR spectroscopy. That immensely sophisticated, composite topic is dissected in a remarkably accessible manner by Klavs Martin Sørensen, Frans van den Berg and Søren Balling Engelsen in Chapter 7. 8 The chapter may be considered a comprehensive yet compact tutorial to the most essential chemometric tools and approaches, in which the data-analytical problems commonly faced in NIR spectroscopy are illustrated on the basis of carefully selected examples.
Chapter 8 – New trend in instrumentation of NIR spectroscopy: Miniaturization
The past decade marked the wide-spreading of portable and miniaturized NIR spectrometers. This breakthrough in technology had a profound impact on the applications of NIR spectroscopy, opening the path to emerging new roles and revolutionizing the existing ones. The merits of the novel instrumentation and the challenges related to miniaturization are discussed in detail by Christian Huck in Chapter 8. 9 That contribution offers a comprehensive presentation of the topic, from the principles of technology, through the linkage between the selection of the particular engineering solutions and the application potential, to the currently pursued research into the analytical performance of those instruments in various scenarios.
Chapter 9 – NIR optics and measurement methods
The key issues related to the design of a NIR spectrometer, as seen from the perspective of the practical applications, are discussed by Akifumi Ikehata in Chapter 9. 10 Key building blocks of a spectrometer and the variety of the existing engineering solutions implementing these blocks are discussed. The reader will find therein comprehensive answers to critical questions, such as what key components constitute a NIR spectrometer or how each element influences the performance of an entire instrument. This information is linked with practical knowledge essential in NIR spectroscopy, e.g. the optimization of the measurement conditions.
Chapter 10 – Hardware of near-infrared spectroscopy
In Chapter 10, Tsutomu Okura outlines the principles of hardware in NIR spectroscopy. 11 Various parameters related to how different types of spectrometers used in NIR spectroscopy operate, including the solutions implemented in miniaturized hardware are inspected. The problem of instrumental difference, its influence on the robustness and flexibility of the analytical application and the measures for controlling that phenomenon are given it the chapter as well.
Chapter 11 – Time-of-flight spectroscopy
Tetsuya Inagaki and Satoru Tsuchikawa summarize principles and applications of time-of-flight (TOF) NIR spectroscopy. 12 That potent unique technique discriminates between the contribution of scattering and absorption simultaneously occurring in the analysed sample. The principles of TOF NIR spectroscopy are discussed on the basis of its applications in key areas including agricultural, medical and forest-related types of samples.
Chapter 12 – Method development
The framework for analytical application of NIR spectroscopy in the environment requesting strict procedures, such as the case of pharmaceutical industry, is discussed by Benoît Igne, Gary McGeorge and Zhenqi Shi in Chapter 12. 13 The concept of the analytical quality by design process, which dictates how the general procedure for method development and maintenance throughput its lifecycle, is presented. The key elements of this process, the design of the method, its testing and validation and monitoring and control of error are covered in detail.
Chapter 13 – Overview of application of NIR spectroscopy to physical chemistry
While NIR spectroscopy is mostly recognized for its direct analytical applications, attention should be given to its significance in basic research in the area of physical chemistry. This topic is discussed in Chapter 13 by Mirosław A Czarnecki, Krzysztof B Beć, Justyna Grabska, Thomas S Hofer and Yukihiro Ozaki. 14 That contribution highlights the unique advantages of NIR spectroscopy that have been exploited in the investigations of a variety of problems in the area of basic research, e.g. anharmonicity, intermolecular interactions, hydrogen bonding, molecular structure, solvent effect, clustering, phase transitions or kinetics.
Chapter 14 – Application of NIR in agriculture
Agricultural applications were particularly important for the early development of NIR spectroscopy. The innovation and stimulus for further advance have remained particular vivid therein, e.g. with significant breakthrough resulting from portable and handheld instruments. Chapter 14 by Vincent Baeten and Pierre Dardenne summarizes current state of the art in this area of application. 15 The chapter highlights the contemporary trends on the basis of a selection of recently completed or current projects.
Chapter 15 – Applications: Food science
Marena Manley and Paul James Williams discuss the applications of NIR spectroscopy in food science in Chapter 15. 16 The intrinsic advantages of this technique have become further enhanced by the availability of portable spectrometers and pre-configured factory calibrations. The current progress into the detection of food adulteration and establishment of NIR spectroscopy as a suitable quality control method in a growing number of analytical scenarios encountered in food and beverage industries are overviewed.
Chapter 16 – Wooden material and environmental sciences
In Chapter 16, Te Ma, Satoru Tsuchikawa and Tetsuya Inagaki, the characteristics of NIR spectroscopy as an analytical tool used in the field of wood and environmental science are summarized. 17 The chapter discusses, among others, the applications of NIR spectroscopy in the analysis of wooden materials, soil, sediment, atmospheric gases, waste liquids and archaeological items. These topics are explained on the basis of representative examples from relevant literature.
Chapter 17 – Information and communication technology in agriculture
Advanced unique applications, among others those enabled by the geographic information system and unmanned aerial vehicles, have instituted NIR spectroscopy in previously unfeasible roles. In Chapter 17, Eizo Tazara presents to the reader the innovation brought to the applications of NIR spectroscopy by the information and communication technology. 18
Chapter 18 – Near-infrared spectroscopy in the pharmaceutical industry
Benoît Igne and Emil W Ciurczak survey in Chapter 18 state-of-the-art NIR spectroscopy in the pharmaceutical industry. 19 The technique advanced considerably in its sensitivity, robustness and deployability, currently enabling its independent application in in-line and in real-time monitoring and control of pharmaceutical manufacturing processes. The factors deciding about the applicability of NIR spectroscopy in this role, its suitability for raw material identification and counterfeit detection, and related topics are covered in detail in the chapter.
Chapter 19 – Bio-applications of NIR spectroscopy
Unique advantages of NIR spectroscopy have paved the way to a variety of applications in widely understood bioscience. The examples of highly successful utilization of this technique in various areas have been evidenced. Nonetheless, in several other aspects, NIR spectroscopy struggled as other techniques have typically been preferred, e.g. when chemical selectivity and sensitivity of the analysis are stressed. Recent progress demonstrated that, in the wake of advances made in instrumentation and spectra-analytical methods, a growing attention is given to the future potential of NIR spectroscopy in this area of application. That fascinating topic is presented to the reader by Christian Huck in Chapter 19. 20
Chapter 20 – Medical applications of NIR spectroscopy
The role that NIR spectroscopy plays in medical sciences is explained by Herbert Michael Heise in Chapter 20. 21 Among others, the profound role of this technique in clinical chemistry, in vitro laboratory procedures as well as in vivo monitoring where it is valued as the non-invasive tool are overviewed in that contribution. Recent breakthroughs in medical applications of NIR spectroscopy enabled by the advances in the technology and data-analytical methods are evaluated from the point-of-view of practical feasibility.
Chapter 21 – Applications of NIR techniques in polymer coatings and synthetic textiles
In Chapter 21, Tom Scherzer presents to the reader a highly specialized role of NIR spectroscopy in in-line analysis of polymer coatings and textiles from synthetic fibers. 22 The peculiarities of the industrial needs for controlling the properties of these materials, and state-of-the-art NIR spectroscopy in that unique role are presented in a comprehensive way, while the discussion is based on a variety of relevant examples.
Chapter 22 – NIR imaging
Daitaro Ishikawa, Mika Ishigaki and Aoife Ann Gowen survey the exciting field of NIR imaging technique in Chapter 22. 23 That remarkably potent tool combines the common advantages of NIR spectroscopy with the highly desired ability to provide spatially-resolved information on the sample. With the capacity to provide rapid, stable monitoring in a non-destructive way of analysis, NIR imaging meets an increasing interest in a variety of the typical applications of NIR spectroscopy and opens the pathway for entirely new roles. NIR imaging technology is constantly advancing, while the progress made in data-analytical algorithms, chemometrics and image analysis methods, continuously redefine the practical potential of this technique in variety of scenarios.
Chapter 23 – Inline and online process analytical technology with an outlook for the petrochemical industry
The new outlook for the application of NIR spectroscopy in petrochemical industry, brought by the revolution in information technology is surveyed by Rudolf W Kessler and Waltraud Kessler in Chapter 23. 24 Beyond the general perspective on the topic, a variety of detailed deliberations are presented to the reader. The measurement configuration setup and conditions to be met, as well as a number of related topics are touched in the chapter. The role of NIR spectroscopy in the industry, in connection the current regulations and institutional reference programs such as Industrie 4.0 and similar initiatives is discussed as well.
Summary
Remarkable advancements in NIR spectroscopy made it desirable to design a new comprehensive handbook that would include entirely new subjects and revisit other meaningful topics to provide the community with updated information on this fascinating and complex discipline. The resulting “Near-Infrared Spectroscopy Theory, Spectral Analysis, Instrumentation, and Applications” book aims to provide a comprehensive handbook readily available to guide the audience into current state-of-the-art NIR spectroscopy. It is the editors’ and authors’ intention that their contribution will serve as a general sourcebook, useful for scholars, professionals and students. The balanced content of the sourcebook forms a formidable assistance when searching for solutions to diverse real-world problems as well as provides fundamental knowledge on a variety of topics relevant to NIR spectroscopy.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.