Bleaches product characterization

The quantitative determination of sterenes has been used to detect added CBEs or refining in cocoa butter and to establish the presence of CBAs in retail chocolates (Crews et al., 1997). The high quantity of triterpene alcohols in shea butters means that dehydration products of these sterols are formed in detectable levels when shea is bleached. These triterpene sterenes, which have not be characterized, can be detected in the stearin fraction used in CBEs (Crews etal., 1999). 

Interest has been restricted this year to studies of photoelimination of nitrogen from arenediazonium salts and attempts to characterize the resulting aryl cations. Nanosecond laser photolysis techniques have been used to examine the photodecomposition of diazonium tetrafluoroborates. Aryl cations could not directly be detected, but evidence from bleaching experiments indicates that, in water, the phenyl cation has a lifetime of about 500 ps. The isolation of the ether (131) as the sole product of photodecomposition of the diazonium salt (132) in methanol demonstrates that rearrangement of the intermediate aryl cation does not occur. Both heterolytic and homolytic pathways have been described for photodecompositions of arenediazonium salts complexed with crown ethers. A useful synthetic application of this conversion is the formation in 53% yield of ethyl 2,4-difluoroimidazole-5-carboxylate (133) on irradiation of the diazonium fluoroborate (134). ... 

F Osterberg, K Lindstrom. Characterization of the high molecular mass chlorinated matter in spent bleach liquors (SBL). 3-mass spectrometric interpretation of aromatic degradation products in SBL. Org Mass Spectrometry 20 515-524, 1985. 

K Addleman, T Dumonceaux, MG Paice, R Bourbonnais, F Archibald. Production and characterization of Trametes versicolor mutants unable to bleach hardwood kraft pulp. Appl Environ Microbiol 61(10) 3687-3694, 1995. 

Once the appropriate treatment process has been selected to transform the bleach active into a suitable physical form, a manufacturing process has to be developed. Alternatively, sourcing from a supplier can be considered. In both cases, the product properties of sample material must be examined, and the fit to the defined requirements needs to be assessed. To characterize the product and powder properties of the finished (soUd) bleach components, a wide variety of test methods is... 

---