ARS | Publication request: Preliminary studies of non-aqueous volatiles in lint cotton moisture tests by thermal methods

Submitted to: Textile Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 28, 2009
Publication Date: April 30, 2010
Citation: Montalvo Jr, J.G., Von Hoven, T.M., Cheuk, S.Y., Schlinder, A. 2010. Preliminary studies of non-aqueous volatiles in lint cotton moisture tests by thermal methods. Textile Research Journal. 80(13):1360-1376.

Interpretive Summary: Moisture in cotton is important because the fiber properties (mechanical, dimensional and electrical) are dependent on the moisture content. The standard test methods for moisture in lint cotton are based on oven drying at 105oC; all of the loss in weight is attributable to moisture. The U.S. cotton industry questions the reliability of the oven-drying method due to the non-aqueous volatiles released during drying may be of an amount sufficient to bias the results. Our approach in these initial studies was to conduct a series of probing experiments to help understand the nature of the non-aqueous volatiles. Cottons were assayed for moisture content by standard oven drying and titration of water by iodine reagent, which is more selective for moisture. The titration results were significantly lower. We oven-dried cottons of varying sample size, changed the gaseous atmosphere during heating from air to nitrogen and attempted to “fingerprint” the non-aqueous volatiles. The results demonstrate complicated side reactions occur during oven-drying. However, no specific volatile organics were detected at standard oven-drying conditions.

Technical Abstract: The standard test methods for moisture in lint cotton are based on oven drying at 105 - 110oC. All of the loss in weight is attributable to moisture. The U.S. cotton industry questions the reliability of the oven-drying method due to the non-aqueous volatiles released during drying may be of an amount sufficient to bias the results. Our approach in these initial studies was to conduct a series of probing experiments to help understand the nature of the non-aqueous volatiles. Cottons were assayed for moisture content by standard oven drying and Karl Fischer Titration. The titration results were significantly lower. We oven-dried cottons of varying mass, changed the gaseous atmosphere during heating from air to nitrogen and attempted to “fingerprint” the non-aqueous volatiles by TGA and TGA-QMS. The results demonstrate complicated side reactions occur during oven-drying. However, no specific volatile organics were detected at standard oven-drying conditions.