432
C. W. Huck
the characteristic bands of the solvent and soluted molecules is possible. A comprehensive review of the NIR research on water structure and properties is available in
the recent literature [37].
A novel way of interpretation of the complex NIR spectra of biomolecules is
available through quantum chemical calculation [1]. A comprehensive presentation
of this topic is available in Chapter 5 of this book, Introduction to Quantum Vibrational Spectroscopy; therefore, accomplishments essential to further development of
bio-applications of NIR spectroscopy are highlighted here. Recently, NIR spectra of
several biomolecules such as short-, [29] medium-, [30] and long-chain [31] fatty
acids, as well as nucleic acid bases, [32] were successfully reproduced with these
methods and their absorption bands could have been comprehensively explained
by Be´ c, Grabska and co-workers [1, 29–32]. This approach was also helpful in
interpreting the meaningful wavenumbers in PLSR model of bio-active compounds
in plant medicines. Few important bio-active constituents of medicinal plants and
natural products have been examined by this approach, e.g., thymol [38] and RA [3].
The studies of thymol supported by spectra simulation yielded fundamental findings
about the relationship between the specific vibrational modes and the features of
PLS regression coefficients vector [38]. This approach is essential for improving the
inherently inferior chemical specificity, which is one of the few properties of NIR
spectroscopy at which it exemplifies a great room for improvements in comparison
with IR or Raman spectroscopy.
19.11 Conclusions
NIR spectroscopy in the bio-fields offers a huge potential in various applications
following its advantages: wide applicability to variety of samples, capability of
examining moist samples, flexible instrumentation including miniaturized sensors.
Accompanied by advanced chemometric data analytical tools, NIR spectroscopy has
been proved to be of great value in various bio-scientific investigations. On the other
hand, in certain other fields, it is still a developing discipline, with room for improvement as compared with other techniques. For example, in bioanalytical research and
medical diagnosis, it still faces strong competition from IR and Raman spectroscopy.
However, the recent literature indicates that NIR spectroscopy steadily conquers this
demanding field of application. In the near future, additional support might come
by quantum chemical simulation of spectra. New achievements accomplished at this
field enable improving the interpretability of NIR spectra; shortening the gap between
this technique and highly chemical specific IR or Raman spectroscopy. Novel handheld NIR spectrometers are indispensable in on-site examination of medicinal plants
with aim to optimize the cultivation conditions and ensure highest quality of natural
drugs. Progress in the instrumentation enabled engineering remote NIR sensors as
well. Airborne, UAV-mounted NIR spectrometers become increasingly important in
environmental monitoring, where, e.g., large amount of data on is collected on flora
C. W. Huck
the characteristic bands of the solvent and soluted molecules is possible. A comprehensive review of the NIR research on water structure and properties is available in
the recent literature [37].
A novel way of interpretation of the complex NIR spectra of biomolecules is
available through quantum chemical calculation [1]. A comprehensive presentation
of this topic is available in Chapter 5 of this book, Introduction to Quantum Vibrational Spectroscopy; therefore, accomplishments essential to further development of
bio-applications of NIR spectroscopy are highlighted here. Recently, NIR spectra of
several biomolecules such as short-, [29] medium-, [30] and long-chain [31] fatty
acids, as well as nucleic acid bases, [32] were successfully reproduced with these
methods and their absorption bands could have been comprehensively explained
by Be´ c, Grabska and co-workers [1, 29–32]. This approach was also helpful in
interpreting the meaningful wavenumbers in PLSR model of bio-active compounds
in plant medicines. Few important bio-active constituents of medicinal plants and
natural products have been examined by this approach, e.g., thymol [38] and RA [3].
The studies of thymol supported by spectra simulation yielded fundamental findings
about the relationship between the specific vibrational modes and the features of
PLS regression coefficients vector [38]. This approach is essential for improving the
inherently inferior chemical specificity, which is one of the few properties of NIR
spectroscopy at which it exemplifies a great room for improvements in comparison
with IR or Raman spectroscopy.
19.11 Conclusions
NIR spectroscopy in the bio-fields offers a huge potential in various applications
following its advantages: wide applicability to variety of samples, capability of
examining moist samples, flexible instrumentation including miniaturized sensors.
Accompanied by advanced chemometric data analytical tools, NIR spectroscopy has
been proved to be of great value in various bio-scientific investigations. On the other
hand, in certain other fields, it is still a developing discipline, with room for improvement as compared with other techniques. For example, in bioanalytical research and
medical diagnosis, it still faces strong competition from IR and Raman spectroscopy.
However, the recent literature indicates that NIR spectroscopy steadily conquers this
demanding field of application. In the near future, additional support might come
by quantum chemical simulation of spectra. New achievements accomplished at this
field enable improving the interpretability of NIR spectra; shortening the gap between
this technique and highly chemical specific IR or Raman spectroscopy. Novel handheld NIR spectrometers are indispensable in on-site examination of medicinal plants
with aim to optimize the cultivation conditions and ensure highest quality of natural
drugs. Progress in the instrumentation enabled engineering remote NIR sensors as
well. Airborne, UAV-mounted NIR spectrometers become increasingly important in
environmental monitoring, where, e.g., large amount of data on is collected on flora