Use of p-dimethylaminobenzalhyde as a colored reagent for determination ofprocaine hydrochloride by spectrophotometry

Spectrophotometric determination of procaine hydrochloride is described. Th e procaine hydrochloride reacts with p-dimethylaminobenzalhyde in glacial a cetic acid to form an Schiff base which is a yellow compound, and its maxim um absorption wavelength is at 455nm, epsilon (455) = 3.46 x 10(4). The abs orbance for procaine hydrochloride from 0.2 to 15 mug ml(-1) obeys Beer's l aw. The linear regression equation of the calibration graph is C = 5.866A - 0.02, with a linear regression correlative coefficient is 0.9994 and relat ive standard deviation (RSD) of 1.7%; the detection limit is 0.1 mug ml(-1) ; recovery is from 92.0 to 110.0%. Effects of reaction medium, temperature, gentamycin, beneylpenicillin, kanamycin, streptomycin, foreign ions, and s tand for time on the determination of procaine hydrochloride have been exam ined. The results obtained by this method agreed with those by the official method (dead-stop titration). This method is rapid and simple, and can be used for the determination of procaine hydrochloride in injection solution of procaine hydrochloride. (C) 2000 Elsevier Science B.V. All rights reserv ed.