Preliminary evidence of oxidation in standard oven drying of cotton: attenuated total reflectance/Fourier transform infrared spectroscopy, colorimetry, and particulate matter formation

Abstract

Currently, oven drying in air is often utilized to generate the percentage of moisture in cotton fibers. Karl Fischer Titration, another method for cotton moisture measurement, has been compared to the oven drying method. The percentage of moisture as generated by the oven method tracks those of Karl Fischer Titration, but there are differences between the two. In fact, a bias exists in the measured moisture loss employing the standard oven drying method. In addition, the moisture data collected via Karl Fischer Titration demonstrates smaller variances than those data collected in the oven. The aim of this study is to determine what is causing those differences. In the current report, particulate matter formation and browning of oven-treated cotton samples have been observed, suggesting visible indirect evidence that cotton oxidation may be occurring. It is noteworthy that three types of oxidation processes may be occurring during the current study: heating in air, scouring and bleaching, and periodate-driven processes. The first two oxidative processes yield non-specific products, whereas the periodate-driven oxidative products are well-defined in the literature. Thus, a method was needed to gain direct evidence for this postulated cotton oxidation that may be contributing to the bias in the standard oven drying method used to calculate moisture loss in cotton. Thus, this preliminary study employed Attenuated Total Reflectance/Fourier Transform Infrared spectroscopy to determine if direct evidence for oxidation can be observed for oven-treated cotton samples.