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.     

Testing for antibacterial properties of cotton/flax denim

The ‘AATCC Test Method 100-1999, Antibacterial Finishes on Textile Materials: Assessment of’ was modified by not assaying for the initial population density and only reporting the population density at the end of incubation for comparing treatments. This seemed to be a reasonable change since the assay challenges the treatments at the start with the same population inoculum density. This permitted the AATCC Test Method 100-1999 to be flexible and easier for testing materials that may or may not actually exhibit bacteriostatic properties. A substantial savings in material and time was gained by not taking the initial population density. This change allows testing more treatments, using more replicate samples, or shortens the time to conduct the assay which can permit more assays to be conducted. However, the control treatment needs to be integral with each assay; but since this is usually done, this would be a small inconvenience compared to the savings. The assay responded well when used to test fabric containing variable amounts of material with known antibacterial properties. The population density of the challenge bacteria decreased as the concentration of the antibacterial component of the fabric increased. The results from the use of the modified AATCC Test Method 100-1999 assay did not indicate that adding flax provided any additional bacteriostatic properties to the flax denim against the two challenge bacteria, Staphylococcus aureus and Klebsiella pneumoniae. The long held assumption that flax is bacteriostatic or antibacterial was not supported by the results and probably does not contribute to its resistance to rotting as much as its physical or chemical composition.