Preliminary Studies of Non-Aqueous Volatiles in Lint Cotton Moisture Tests by Thermal Methods

Abstract

The standard test methods for moisture in lint cotton are based on oven drying at 105—110°C. 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 concern that 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 thermogravimetric analysis and thermogravimetric analysis—quadrupole mass spectrometry. The results demonstrate that complicated side reactions occur during oven-drying. However, no specific volatile organics were detected at standard oven-drying conditions.