ANALYSIS OF FLUORESCENT WHITENING AGENTS IN THE JAPANESE PHARMACOPEIAABSORBENT GAUZE USING REVERSED-PHASE TLC, SPECTROFLUOROPHOTOMETER ANDHPLC WITH FLUORESCENCE DETECTOR

The purity test of the Japanese Pharmacopoeia Absorbent Gauze for fluo rescent whitening agents is regulated to perform by a method of irradi ating the gauze with ultraviolet rays in a dark place. This method has been reported to have a difficulty in detecting the existence of fluo rescent whitening agents in several cases. We, therefore, tried to est ablish a method to examine the existence of fluorescent whitening agen ts using physical and chemical methodologies. After cutting the Japane se Pharmacopoeia Absorbent Gauze samples in small pieces, fluorescent whitening agents were extracted by 30% pyridine solution at 100 degree s C for 30 min. We analysed the fluorescent agents using reversed phas e TLC, spectrofluorophotometer and HPLC with a fluorescence detector u sing 8 standard fluorescent whitening agents as controls. Conditions o f reversed phase TLC: plate, RP-18W (Merck); solvent system, A) aceton itrile-water (1:4), B) acetonitrile-methanol-water ( 3 : 3 : 10), C) m ethyl ethyl ketone-methanol-water (1 : 1 : 1). Conditions of HPLC with fluorescence detection: column, Wakosil 5C18 (i.d. 4.6 x 150 mm); mob ile phase, 0.01M ammonium acetate-acetonitrile (7 : 3); flow rate, 1.0 ml/min; injection volume, 20 mu l; detections, fluorescence detector (excitation 345 nm and emission 435 nm).