Development of Chemometrics

The early history of chemometrics is documented by published interviews with Bmce R. Kowalski, D. Luc Massart, and Svante Wold who can be considered as the originators of modem chemometrics (Esbensen and Geladi 1990 Geladi and Esbensen 1990). A few, subjectively selected milestones in the development of chemometrics are mentioned here as follows ... 

Finally, the development of chemometrics over the past 20 years has also aided in the use of UV-vis technology for more complicated chemical matrices than was possible at earlier times. Chemometrics allows large quantities of spectral data to be analyzed and reduced to a useful bit of information such as the concentration of one or more chemical species. In addition, through analysis of residuals, it is possible to detect when something unexpected occurs in a process. 

All technologies are bnilt npon a fonndation of previously-existing technologies, principles and protocols. There are several of these that were critical to the development of chemometrics, and the ones that are most relevant to PAT applications will be discussed in this section. 

Experimental design tools are widely considered to be some of the most important tools in the development of chemometric models.20 At the same time, however, it is important to note that these tools can be effectively applied only in cases where sufficiently relevant... 

Near-infrared spectroscopy (NIRS) has become a very popular technique for a wide range of analysis in various industries. The usefulness of this technique is mainly attributed to allowing the rapid analysis of bulk materials with a simple manipulation procedure. On the other hand, improvements of instrumentation, and specially the development of chemometric software, have contributed to the tremendous expansion of and to the current state of popularity of this technique (Bokobza, 2002). 

In the past decade, the development of chemometrics has found its expression in the publication of two journals specializing in chemometrics Chemometrics and Intelligent Laboratory Systems (1986) and Journal of Chemometrics (1987) the increasing importance of chemometric methods in the field of environmental research is apparent from the publication of the journal Environmetrics (1990). As a consequence of the rapidly increasing number of papers dealing with chemometrics, a reference journal Windows on Chemometrics has been published since 1993. 

The future development of chemometrics may be characterized by the balancing of opposites [GELADI, 1995] combination of hard and soft information, using a priori information when available and combining with a posteriori information. So, a holistic strategy (Fig. 1-2) with different chemometric methods in each of its steps may help to solve problems of the real world of chemistry and other disciplines . 

Development of chemometric methods for full quantification of the biomass tar compounds... 

The use of mathematical and statistical modeling methods to relate chemical data sets to the state of the chemical system is referred to as chemometrics. A key figure in the development of chemometrics and its application to industrial problems has been B.R. Kowalski [18, 147, 319] who led the Center for Process Analytical Chemistry (CPAC) that was established in 1984. To aid qualitative and quantitative analysis of chemical data, Eigenvector Technologies Inc., a developer of independent commercial software, has provided a number of software solutions, primarily as a Matlab Toolbox [328]. 

Near-IR spectroscopy arises from transitions in which a photon excites a normal mode of vibration from the ground state to the second or higher excited vibrational state (overtones, vide infra) or transitions in which one photon simultaneously excites two or more vibrational modes (combinations bands, vide infra). The use of the near-IR, especially diffuse reflection spectroscopy, in both quantitative and qualitative analysis has increased significantly due to better instrumentation and the development of chemometrics to better handle the effect of seriously overlapping bands. 

Near-infrared spectroscopy as a valuable tool for qualitative and quantitative analysis [174], [175] has experienced a revival through the development of chemometric methods and the introduction of fiber optics during the 1980s, and high-quality near-infrared spectra are provided by improved conventional and by Fourier transform instruments. 

The use of infrared spectroscopy to provide quantitative information on multicomponent systems has blossomed in recent years, spurred on by the development of chemometric techniques which have revitalised NIR spectroscopy. The principle of multicomponent analysis is outlined below, but see the books by Martens and Naes [13] and Massart et al. [14] for more thorough developments of these ideas. 

There are other advances in the RS technique, unrelated to sensitivity improvement, that need to take place in order for it to be more widely applied to environmental problems in aqueous systems. Many of these advances will require more sheer determination than innovation. These advances include the following improvements in methods for routine intensity and frequency calibration availability of inexpensive, accurate, and large Raman computerized spectral libraries, including spectra recorded in aqueous media development of chemometric techniques specifically tailored for RS improvements in methods for cross-instrument calibration. Currently, there are efforts underway to address most of these needs, and considerable progress is being made. Fortunately, there are lessons that can be... 

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