Whitening alternating

An alternative approach is to physicaUy separate the FWA from the wool fiber by incorporating the whitener into a suitable surface polymer treatment for wool fabric (119). The photostabUity of these fabrics is significantly better than conventional FWA treatments, being similar to bleached wool. 

Applications With the current use of soft ionisation techniques in LC-MS, i.e. ESI and APCI, the application of MS/MS is almost obligatory for confirmatory purposes. However, an alternative mass-spectrometric strategy may be based on the use of oaToF-MS, which enables accurate mass determination at 5 ppm. This allows calculation of the elemental composition of an unknown analyte. In combination with retention time data, UV spectra and the isotope pattern in the mass spectrum, this should permit straightforward identification of unknown analytes. Hogenboom et al. [132] used such an approach for identification and confirmation of analytes by means of on-line SPE-LC-ESI-oaToFMS. Off-line SPE-LC-APCI-MS has been used to determine fluorescence whitening agents (FWAs) in surface waters of a Catalan industrialised area [138]. Similarly, Alonso et al. [139] used off-line SPE-LC-DAD-ISP-MS for the analysis of industrial textile waters. SPE functions here mainly as a preconcentration device. 

Fig. 28. Photograph of the alternating transparent and stress-whitened zones in poIy(ethylene terephthalate) drawn under stress oscillations...

Whiten I was wanting to be non-committal about that. I was saying that social modularity of intelligence is one alternative. But as I also noted, explicit testing of that has been minimal in primatology. It is mainly people working with humans who have been advocating special social modules. 

Mercury is eliminated princip y by the saliva and urine, in which it may be rea y detected. The fluid is faintly acidulated with and in it is immersed a short bar of Zi, around which a spiral of dentist s gold-foil is wound in such a way as to expose alternate surfaces of Zn and Au. After 24 hours, if the saliva or urine contain Hg, the Au will be whitened by amalgamation and, if dried and heated in e closed end of a small glass tube, will give off Hg. which condenses in globules, visible vrith the aid of a magnifler, in the cold part of the tube. 

Treatment of wool with a FWA, followed by post-treatment with thiourea/formaldehyde by a pad/cure method, confers a high level of protection against photoyellowing and also improves the initial fabric whiteness (134). Unfortunately, this process is not commercially viable, partly because of environmental concerns about thiourea and formaldehyde and also because much of the benefit is lost after laundering. An alternative approach is to physically separate the FWA from the wool fiber by incorporating the whitener into a suitable polymer that can be applied as a surface treatment to wool fabrics (135). The photostability of the treated fabrics is somewhat better than for conventional FWA treatments (being similar to bleached wool) but the initial whiteness is significantly lower than that of FWA-treated wool. 

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