Quantitative analysis of cotton (Gossypium hirsutum) lint trash by fluorescence spectroscopy

The presence of cotton plant botanical components, or trash, embedded in lint subsequent to harvesting and ginning is an important criterion in the classification of baled cotton by the U.S. Department of Agriculture Agricultural Marketing Service. The trash particles may be reduced in size to the point that specific trash types are not identifiable by image or gravimetric analysis, and it is desirable to quantify different trash types so that processing lines may be optimized for removal of the most problematic trash to enhance processing performance and cotton lint quality. Currently, there are no methods available to adequately quantify cotton lint trash based on botanical origin. The present work attempts to address this issue through the analysis by fluorescence spectroscopy of dimethyl sulfoxide extracts of mixtures of six botanical trash types. The fluorescence data are subsequently subjected to chemometric analysis. The resulting 6 partial least-squares calibration models obtained from 128 mixtures are demonstrated in the case of leaf and hull to be capable of predicting individual trash component concentrations with a high degree of confidence.