Flow Injection On-line Photochemical Reaction Coupled to Spectrofluorimetry for the Determination of Sulfamethazine Using Sodium Sulfite as Sensitizing Reagent
✍ Scribed by Qiaohong He; Hengwu Chen; Xiaoxia Cao
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 66 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0026-265X
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✦ Synopsis
The reaction medium for photochemically induced fluorescence (PF) of sulfamethazine (SMT) was studied. Sodium sulfite was found effective to enhance the on-line photochemically induced fluorescence intensity of SMT. A flow injection on-line photochemical spectrofluorimetry (FI-PF) using sodium sulfite as sensitizing reagent was developed for the determination of SMT. The injected sample zone was on-line merged with a mixed sodium sulfite-borate buffer (pH 8.8) solution in a knotted PTFE photochemical reactor (0.5 mm i.d. ϫ 150 cm, KR), which was freely coiled around a 6-W low-pressure mercury lamp. While passing the KR the drug was derived into an intensively fluorescent compound which was on-line detected in a flow-through cell at the emission wavelength of 345 nm and excitation wavelength of 287 nm. Compared to FI-PF without using sodium sulfite, the sensitivity of the developed system was improved by at least 6 fold. At the optimized conditions a detection limit of 3.5 g ⅐ L Ϫ1 was achieved at the sampling rate of 90 h Ϫ1 . Eleven determinations of a 0.6 mg ⅐ L Ϫ1 SMT standard solution gave a RSD of 1.2%. The calibration curve was linear in the SMT concentration range 0.02-2 mg ⅐ L Ϫ1 . The proposed method was applied to assay the SMT content in some pharmaceutical formulations. Satisfactory results were obtained.