Nitranilines, determination

In this method the soln of titanous sulfate is standardized against p-nitraniline 6) 120° C Vacuum Stability Test. Using a 2.3 g dry sample and adjusting the apparatus described in Vol 1 of Encycl, p XXVI to 120°, determine the amt of gas evolved in 40hrs of heating. More detailed description of the test is given in MIL-STD-286A (1961). Method 403.1.2 and in PATR 3278(1965), pp 19-22 Fig 15... 

It was found by Williams and Soper [/. Chem, Soc.j 2469 (1930)] that when 1 liter of a solution containing 0.03086 mole of o-nitraniline and 0.05040 mole of hydrochloric acid was shaken with 60 cc. of heptane until equilibrium was established at 25° that 50 cc. of the heptane layer contained 0.0989 g. of the free base. The distribution coefficient of o-nitraniline between heptane and water is 1.790. Determine the hydrolysis constant of the amine hydrochloride. 

Photometric determination with diazotized p-nitraniline in an alkaline medium is carried out either directly (for higher concentrations) or after extraction of the dye into butyl alcohol (for lower concentrations). In the case of the direct determination absorbance is measured at 470 nm (blue filter) and in the case of the extraction, determination at 530 nm (green filter) [14, 37, 49, 73]. 

Photometric determination. The phenols are absorbed in a sodium carbonate solution. A red colour of a relevant azo dye is induced by addition of diazotated p-nitraniline, and may be evaluated by photometry [18]. 

Methods applicable to the determination of salsoline include a colorimetric method introduced by Bezuglyi (54), volumetric titration with diazo-tized p-nitraniline, salsolidine not interfering, as proposed by Konovalova and Zaitseva (55), and electrolytic separation of the alkaloid, according to Babich (56). 

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