DEVELOPMENT AND USE OF AN ATTENUATED TOTAL REFLECTANCE/FOURIER TRANSFORM INFRARED (ATR/FT-IR)SPECTRAL DATABASE TO IDENTIFY FOREIGN MATTER IN COTTON

Authors: HIMMELSBACH, DAVID; HELLGETH, JOHN - HEWLETT PACKER CO.; MCALISTER III, DAVID

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2006
Publication Date: 9/9/2006
Citation: Himmelsbach, D.S., Hellgeth, J.W., Mcalister III,D.D. 2006. Development and use of an attenuated total reflectance transform infrared (ATR/FT-IR) spectral database to identify foreign matter in cotton. Journal of Agricultural and Food Chemistry. 54(20):7405-7412.

Interpretive Summary: Contamination of cotton lint from a variety of sources, both manmade and vegetative, impacts the grade and reduces the value of cotton. Current methods employed to evaluate cotton quality only estimate either the percent of contamination by weight and/or classify it by shape and size. However, they do not address the specific nature or source of the contamination. The application of Fourier-transform infrared spectroscopy in conjunction with the attenuated total reflectance technique goes beyond current capabilities and permits the rapid and specific chemical identification of essentially all contaminants. The method compares the spectrum of excised foreign matter to that of a comprehensive library of materials contained in a spectral database. The library database is a collection of parts of the cotton plant other than fiber, parts of other plants frequently found in or near cotton fields, synthetic and natural materials used to wrap or secure cotton bales and sugars associated with cotton stickiness. High-score matches in the database insure a positive identification of the contaminant. This method is suitable for incorporation with high volume instrumentation. The results provide the knowledge necessary to improve cotton ginning, spinning weaving efficiency and the quality of the final product.

Technical Abstract: The presence of foreign matter in cotton seriously affects the cotton grade and thus the price per bale paid by the spinner to the grower, the efficiency of the spinning ginning and operations and the quality of the final woven product. Rapid identification of the nature of the extraneous matter in cotton at each stage of cleaning and processing is necessary permit actions to eliminate or reduce its presence and improve efficiency and the quality at every stage. Although several instruments are being successfully employed for the measurement of contamination in cotton fibers based on particle size/weight, no commercial instrument is capable of accurate qualitative identification of the contaminant. To this end, the FT-IR/ATR spectra of retrieved foreign matter were collected and subsequently rapidly matched to an authentic component spectrum in a spectral database. The database included contaminants typically classified as "trash": cotton plant parts (hull, shale, seed-coat fragments, bract, cacyx, leaf, bark, sticks and stems) and grass plant parts (leaf and stem), "foreign objects and materials": synthetic materials (plastic bags, film, rubber, bale rapping and strapping) and natural materials (other fibers, yarns, paper) inorganic materials (sand, rust and metal) and entomological and physiological sugars. The spectral matching resulted in consistently high-score identification of the foreign matter based on chemical composition, irrespective of its particle size.