Artificial traces impurities

E.R. Collantes, R. Duta, W.J. Welsh, W.L. Zielinski and J. Brower, Reprocessing of HPLC trace impurity patterns by wavelet packets for pharmaceutical finger printing using artificial neural networks. Anal. Chem. 69 (1997) 1392-1397. 

Thus, the empirical characterization of the OV transient produced from OH in seawater leads to a chemical mystery the UV transient definitely interacts with seawater in a pH and CO2-dependent process that occurs in waters of different origin, including artificial seawater. Hence, the effect would appear to be due to the carbonate system itself, not some trace impurity. The following paper tahes up the challenges of finding such an interaction in simpler media than seawater and of explaining the pseudo first-order decay of seawater in terms of these interactions and carbonate system speciation (16). 

Preprocessing of HPLC Trace Impurity Patterns by Wavelet Packets for Pharmaceutical Fingerprinting Using Artificial Neural Networks. 

The higher aliphatic alcohols, from octyl alcohol upwards, have-recently been introduced as perfume materials with considerable success. Only one or two of them, such as nonyl and undeeylenic alcohols, have so far been detected as natural constituents of essential oils, but other members of the series are prepared artificially, and are employed in minute quantities in the preparation of perfumes with characteristic, fruity bouquets. These alcohols are greatly diminished in perfume value by traces of impurities. According to H. J. Prins, the first interesting member of the series is octyl alcohol it has a very sweet, rose-like odour, and is especially suitable for giving a rose perfume that pecnliar sweet smell which distinguishes a rose from a rose perfume. This feature of the aliphatic alcohols diminishes in the series from Cg to Cjg. 

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