No abstract

No abstract

Two methods for the measurement of pigments occurring in colored grapefruit are outlined and the results compared. Method A involves extraction of the sample, separation of the major pigments-lycopene and carotene-on a magnesia-Super Cel column, elution, and spectrophotometric measurements of the separated pigments. By method B, a more rapid but less precise procedure, the pigment is extracted and the absorptivity of the extract determined a t 451 mp for carotene and 503 mp for lycopene. Results of total concentration of the pigments, as determined by simultaneous equations, show

The potassium bromide disc technique is being used for rapid, simple, and reproducible measurement of the infrared spectra, of modified cotton fibers, yarns, and fabrics. Applications of the procedure have demonstrated that chemical modification can be readily detected and identified and that the extent of treatment can be quantitatively estimated. Experiments have been designed to select bands most useful in investigations of cotton modified by esterification. etherification, or replacement reactions. The examples cited illustrate the potential usefulness of infrared absorption spectra to studies in this field. A list has been prepared of 50 infrared absorption bands (and correlations with vibrating groups which give rise to them) which summarize the spectral characteristics which have been found most useful in investigations of cottons modified by esterification, etherification, and replacement reactions.