title: Colorimetric determination of piperazine with p-benzoquinone.
abstract: Piperazine and its salts are reacted with aqueous alcoholic p-benzoquinone, buffered at pH 5.4, to give a coloured product with maximum absorption at 516nm. The piperazine base has a molar absorptivity of 0.96 x 10(4)l.mole(-1).cm(-1) and Beer's law is obeyed over the range 2-10 mug ml . When applied to three commercial preparations, the proposed method gave mean recoveries within 1% of those obtained by the official gravimetric method. The relative standard deviation was less than 1%.
authors.affiliation: Pharmaceutical Chemistry Department, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh-11451, Saudi Arabia.
authors.forename: A A
authors.initials: AA
authors.lastname: Wahbi
authors.forename: M A
authors.initials: MA
authors.lastname: Abounassif
authors.forename: E A
authors.initials: EA
authors.lastname: Gad-Kariem