EXTRACTION AND SPECTROPHOTOMETRIC DETERMINATION OF AMOXICILLIN AND AMPICILLIN IN PHARMACEUTICAL PREPARATION USING POTASSIUM IODATE

An indirect spectrophotometric determination of amoxycillin and ampici llin based on the extraction of iodine produced by reduction of potass ium iodate, where hydrolytic cleavage of beta-lactam ring of amoxycill in and ampicillin with sodium hydroxide was carried out. The product f ormed was extracted and then determined spectrophotometrically. Beer's law is obeyed over the concentration range 0.04-0.35 mg ml(-1) and 0. 08-0.56 mg ml(-1) for amoxycillin and ampicillin, respectively. The ab sorbance of the colour formed was measured at lambda(max) = 520 nm. An oxidation mechanism is proposed.