Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592


You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: 'Self-absorption' phenomenon in near-infrared Fourier transform Raman spectroscopy of cellulosic and lignocellulosic materials

Source: Applied spectroscopy. Vol. 24, no. 3 (2005): Pages 385-388.

Author(s)Agarwal, Umesh P.; Kawai, Nancy

Publication Year: 2005  View PDF »

Category: Journal Articles

Abstract: While cellulosic and lignocellulosic materials have been studied using conventional Raman spectroscopy, availability of near-infrared (NIR) Fourier transform (FT) Raman instrumentation has made studying these materials much more convenient. This is especially true because the problem of laser-induced fluorescence can be avoided or minimized in FT- Raman (NIR Raman) spectroscopy. More recently, the method has also been used to generate quantitative results in cellulosic and lignocellulosic materials. Although linear dependence of Raman intensity on analyte concentration is well established, the occurrence of self-absorption (defined as absorption of Raman scattered photons by the sample itself) is known to cause problems. The influence of self-absorption in an FT-Raman spectrum is manifested in the spectral region where the sample absorbs as a result of overtone- and combination vibration bands. The net result is that the Raman band intensity or intensities are diminished. This is also true for samples that have an electronic absorption in the visible region and are being analyzed by visible Raman spectroscopy. For instance, researchers have pointed out the occurrence of self-absorption in resonance Raman spectroscopy. Compared to visible Raman spectroscopy, where only a small number of samples have strong electronic absorption, in NIR Raman, many more substances are expected to have overtone and combination-vibration transitions. Additionally, in the latter method,because sampling is deeper, self-absorption can be more problematic. For the present investigation, cellulose filter paper and spruce thermomechanical pulp (TMP) were chosen as representatives of cellulose and lignocellulose, respectively. The objective was to determine whether self-absorption was present in the spectra and which Raman bands were suppressed as a consequence.

Keywords: Self-absorption, near-infrared Fourier transform Raman spectroscopy, cellulose

File size: 102 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 16714
Current FPL Scientist associated with this product
Agarwal, Umesh P.
Research Chemist

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »

Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »

Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »

Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »