Determination of Menadione Sodium Bisulfite in Pharmaceutical Preparations by Flow-Injection On-line Photochemical Spectrofluorometry

Abstract

A flow-injection on-line photochemical spectrofluorometry (FI-PF) was developed for the determination of menadione sodium bisulfite (MSB) using acetone and sodium sulfite as sensitizing reagents. An injected sample band carried by a water stream was on-line merged with a mixed NaOH, Na2SO3 and acetone solution in a "T" connector. It was then driven to pass a knotted PTFE photochemical reactor (0.5 mm i.d. × 200 cm, KR) that was freely coiled around a 6-W low-pressure mercury lamp. While passing the KR, MSB was derived into an intensively fluorescent compound that was on-line delivered into a flow-through cell and detected therein at an emission wavelength of 459 nm and an excitation wavelength of 336 nm. Under optimized conditions a detection limit of 0.38 µg l -1 was achieved at a sampling rate of 90 h -1 . Eleven determinations of 0.5 mg l -1 and 0.05 mg l -1 MSB standard solution gave RSDs of 0.75% and 1.3%, respectively. The calibration curve was linear in the MSB concentration range 0.005 -1.5 mg l -1 . The proposed method was successfully applied to assay the MSB content in MSB injection.

Microplate analytical method for quinones by pulse photo-irradiation and chemiluminescence detection

“…Although the high sensitivity achieved by the fluorescence detection, quinones lack native fluorescence and have to be reduced to their hydroquinone form prior to fluorescence detection. Different procedures are used for quinone reduction, either chemically, [13][14][15] electrochemically 16 or photochemically 17,18 . Although the fluorescence detection may accomplish the required sensitivity, the methods lacked simplicity and rapidity because the reduction processes required many additional systems component such as reducing column, electric reactor or photoreactor.…”

“…Different procedures are used for quinone reduction, either chemically, [13][14][15] electrochemically 16 or photochemically. 17,18 Although the fluorescence detection may accomplish the required sensitivity, the methods lacked simplicity and rapidity because the reduction processes required many additional systems component such as reducing column, electric reactor or photoreactor.…”