THE DETERMINATION OF AMMONIA AND AMIDE NITROGEN IN TOBACCO BY THE USE OF PERMUTIT

Abstract

The accurate determination of the preexisting ammonia or of the amide nitrogt.n of tobacco is rendered difficult by the volatility of nicotine which distils over more or less completely when the standard procedures for the estimation of these forms of nitrogen are employed.A number of attempts has been made to devise methods whereby corrections for the nicotine content of such distillates may be calculated but none of these is entirely satisfactory.Kissling (1) distilled the volatile bases into standard acid, and subtracted from the titration figure the equivalent of the nicotine determined upon another sample by ether extraction.This method for the estimation of the ammonia was shown by Kissling (2) to include some amide nitrogen.It may also include other volatile bases.Harrison and Self (3) removed the nicotine from a similar distillate by precipitation with potassium triiodide reagent and again distilled the ammonia.This method takes no account of the possible presence of other volatile bases.Kissling (4) in 1920 removed the nicotine from the sample by ether extraction and subsequently distilled the ammonia.This method was shown to be inaccurate by Fodor and Reifenberg (5) because some of the ammonia passes into the ether extract.These authors removed the nicotine from the distillate by precipitation with a solution of mercuric iodide in potassium iodide and subsequently distilled the ammonia.This method is open to the same objections as that of Harrison and Self and all of these procedures are time-consuming.