Scoured wool, analysis

One unusual procedure used is the feedback of knowledge about the population. Williams [27] observed that when a calibration is based on a Gaussian distribution of samples with respect to concentration, then the results of the analysis of unknown samples would be regressed toward the population mean. The phenomenon makes one contribution to the skew often observed in the data because the high-concentration samples will be underpredicted and the low-concentration samples overpredicted. In practice skew from this source will be reasonably common for it is very difficult to attain the ideal rectangular distribution of concentration within the calibration set. This is certainly the case for the distribution of residual grease levels in scoured wools. 

Another approach consists of an in-situ acetylation and extraction of NPEOs and further analysis of the acetyl derivatives. The method has been applied to analyse effluent water and sewage sludges [102,103], sediments [104] and river waters [105]. Silylated derivatives [106] using BSA or BSTFA have also been used to determine NPEO (n < 6) in seawater [107] and wastewater [107,108], sediments [109] and sludges from wool scour effluents [110]. Halogenated derivatives of alkylphenols (AP) can also be formed as a result of chlorination practices in water treatment or wastewater if bromide is present. Brominated OPs and NPs (BrAPEOs) have been identified by GC-MS in sewage [111] and tap water [89], respectively. 

For over a decade NIR quality control has been used in the textile and fiber industries. Perhaps the widest use of NIR has been in the cotton industry. Cotton blending, mercerization, and fiber maturity measurement have been used offline for rapid process control. The wool industry has also employed NIR to measure the residual grease after scouring. Calibrations have been developed for measuring moisture and heat set temperature in nylon yam. Online NIR analysis is being developed for the quality control of the dyeing procedure for carpet yam and for measuring yarn diameter. 

Sherrard, K. B., P. J. Marriott, M. J. McCormick, R. Colton, G. Smith, Electrospray MS analysis and photocatalytic degradation of polyethoxylate surfactants used in wool scouring. Anal. Chem., 1994,66, 3394-3399. 

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