Visible spectrophotometric method for the determination of some typical aromatic primary amines by using p-N, N-Dimethylphenylenediamine and iodine

p-N,N-dimethyl phenylene diamine(DMPD) is oxidized with Iodine into p-N,N-dimehylbenzoquinonemonoimine which can form a purple –red charge –transfer complex with aromatic primary amine (APA) at pH 3.0 . The absorbance of the p-N,Ndimehylbenzoquinonemonoimine – APA charge-transfer complex is measured at 520nm. This proposed method is simple, rapid and sensitive with reasonable precision and accuracy. The precision of the method was found by analyzing a set of eight solutions, each containing a final concentration value approximately in the middle of the Beer’s law range. The percent relative standard deviation in this method is presented in table-1. The accuracy of the method was determined by taking different known amounts (with in Beer’s law limits) of the drug and analyzing them by proposed method. The results are given in table-2. In the determination of APA the excipients usually present in formulations did not interfere.