Identification of Common Cotton Contaminants using an FTIR Microscope with a Focal Plane Array Detector

In this study, a Fourier transform infrared (FTIR) microscope equipped with a focal plane array detector (FPA) was used for the identification of common cotton contaminants. The detector provided highly-sensitive and spatially-resolved spectra that allows sampling of microscopic samples (e.g., single fibers and small specks), and the chemical imaging of samples. Seven cases of contaminant identification were studied; in each case, examination with a FTIR spectrometer and a reflection accessory provided inconclusive determinations. Spectra of contaminants were easily obtained with the FTIR microscope. While small deviations were observed, comparison to reference spectra allowed easy contaminant identification. This proof-of-concept study indicates that the FTIR-FPA microscope was particularly useful for identifying minute contaminants. Spatial resolution of the system also allowed for the chemical imaging of samples.