Relationship between near-infrared (NIR) spectra and the geographical provenance of timber

Relationship between near-infrarThe goal of this study was to verify whether significant differences among groups of the same wood species due to the provenance can be detected with Fourier transform near-infra-red spectroscopy (FT-NIR). Spruce (Picea abies L. Karst.) samples collected from stands in Finland, Northern and Southern Poland and Italy were analyzed using two different approaches: for the first approach samples were collected from four provenances scattered in a wide area throughout Europe, while for the second approach the samples were collected from provenances located in a narrow area within the same region in Italy. For the first approach, all the specimens were clearly divided into groups by using statistical methods. The separation among groups from the narrow local area was actual; even though less significant than in the previous case. It was concluded that trees growing in various locations have somewhat different chemical composition, and FT-NIR is sensitive enough to detect such differences. The presented method could be used for tracking wood provenances and as a technical tool for detecting logs harvested illegally from protected areas.

Near infrared spectroscopy as a tool for archaeological wood characterization
Archaeological wood, as most of natural materials, is slowly decomposing on the archaeological site due to various biological factors. Rapid and accurate estimation of the degradation level is extremely important for optimal restoration and conservation. The goal of this research was to verify the effectiveness of Fourier transform near infrared (FT-NIR) spectroscopy for archaeometry. The important advantage of the NIR spectroscopy is its accuracy, simplicity and ability to perform very high number of tests without needs of any destruction to the workpiece. Five oak pieces of the archaeological wood collected from waterlogged sites in Poland have been used. Cellulose and lignin contents, as well as crystallinity and the degree of polymerization were measured with standard reference methods and compared to the contemporary wood. The near infrared spectra represent all the physical/chemical changes of the wood due to waterlogging. This technique was successfully validated in rapid estimation of the cellulose and lignin contents. The method explored in this research might be a novel tool assisting experts in evaluation of the degradation state of archaeological and historical wooden materials.

FT-NIR analysis of recycled paper
The goal of this work was to develop a methodology for estimation of the biodegradation rate
of recycled papers by using FT-NIR. Two types of fungi, Chaetomium globosum and a mixture of Aspergillus niger, Trichoderma viride and Penicillium funiculosum were used as biotic cultures. Paper sheets made of recycled fibers with addition of 0, 3, 5, and 10% of bran cereal were used as workpieces. Breaking length and degree of fungal infestation (according to custom scale) were performed at 2, 4, 7, 10, 14 and 21 day after infection for quantification of the paper resistance to biodegradation. The surface of paper was also measured with FT-NIR spectrometer. It was found that addition of wheat bran (3%) and rye (3% and 5%) increased susceptibility to sprouting by the fungi, compare to samples without bran. Degradation of papers infected by Ch. globosum was generally most intensive. FT-NIR analyzes reviled that the most significant changes to the spectra were noticed at wavenumbers of 4280, 4404 and 4620-4890cm-1, what corresponds to CH, CH2 and OH functional groups of cellulose respectively. Changes to the FT-NIR spectra were in good agreement with the reference methods and therefore this technique has a potential for monitoring of the paper biodegradation process.

Contatto

Anna Sandak

[Last updated on: 02-11-2015]
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