Determination of wool wax in raw wool by Raman spectroscopy

A Raman spectroscopic method for the determination of wool wax content in raw wool has been developed. The analyses were performed on 250-mg wool samples by using a spectral component band resolution method. The method has a moderate sample throughput rate, is non-destructive and does not require the use of solvents. Samples ranging between 0.5 and 31% (w/w) wool wax were analyzed. The results obtained were compared with those obtained by a solvent extraction method. If the nonextractable lipid content of the wool is considered, the results of the Raman spectral and extraction methods were in excellent agreement. From a practical standpoint, the minimum detection limit of the method is 3% wax. In general, the precision of the Raman spectroscopic method was better than that obtained for the extraction method.