Other Trace Impurities

As a result of the clandestine processes used in the production of heroin, the final product may contain not only heroin but also monoacetylmorphine, acetylcodeine, opium alkaloids, and other trace impurities. At the street level, heroin exhibits also contain adulterants such as quinine, procaine, methapyrilene, and various sugars. The determination of all these substances provides a good basis on which to compare heroin exhibits. 

Low-temperature adsorption systems continue to find an increasing number of applications. For example, systems are used to remove the last traces of carbon dioxide and hydrocarbons in many air-separation plants. Adsorbents are also used in hydrogen liquefaction to remove oxygen, nitrogen, methane, and other trace impurities. They are also used in the purification of helium suitable for liquefaction (grade A) and for ultrapure helium (grade AAA, 99.999% purity). Adsorption at 35 K will, in fact, yield a helium with less than 2 ppb of neon, which is the only detectible impurity in helium after this treatment. 

Du, B., R, Pollard, and J.F. Elter. 2009. Performance and durability of a polymer electrolyte fuel cell operating with reformatted Effects of CO, COj, and other trace impurities. In Polymer electrolyte fuel cell durability, eds. F.N. Buchi, M. Inaba and T.J. Schmidt, pp. 341-366. New York, NY Springer. 

Performance and Durability of a Polymer Electrolyte Fuel Cell Operating with Reformate Effects of CO, CO2, and Other Trace Impurities... 

The process is of particular importance in the removal and recovery of volatile organic compounds (VOCs) and the removal of obnoxious odors or other trace impurities from air streams in connection with air pollution control. It is used to a lesser extent to recover hydrocarbons from natural, manufactured, and coke oven gases, although this was formerly a major application. 

In addition to the six primary reactions discussed above, formaldehyde, N,N,N N -tetramethyldiaminomethane, and other trace impurities are known to be generated by side... 

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