Enhanced flow-injection–chemiluminometric determination of sulphonamides by on-line photochemical reaction

摘要: Abstract The viability of the tandem photochemical reaction-chemiluminescence detection has been studied for an heterogeneous group sulphonamides (sulphamethoxazole, sulphadiazine, sulphamerazine, sulphamethoxypyridazine, sulphacetamide, sulphadimidine, sulphanilamide, sulphathiazole and sulphaguanidine) using sulphamethoxazole (whose chemiluminescent behaviour not previously reported) as a test substance. ‘on-line’ photochemical-reaction provides enhancing influence on chemiluminometric response drugs during their oxidation by potassium permanganate in sulphuric acid medium sulphadimidine sulphanilamide increase factor≥10). determination is performed FI-assembly photoreactor consisting 670 cm×0.5 mm i.d. long piece PTFE tubing coiled around 8 W low-pressure mercury lamp. Linear calibration graphs were obtained over concentration range 2–3 orders magnitude, typically ≈0.06–8 μg ml−1 sulphathiazole, sulphaguanidine); ≈0.08–100 μg ml−1 (sulphadiazine, sulphamerazine sulphamethoxypyridazine). Limits between 30 μg l−1 (for sulphanilamide) 80 μg l−1 sulphaguanidine). sample throughput was 60 h−1 all cases. assessment photodegradation step molecular structure sulfonamides established recording UV fluorimetric spectra. on-line reaction-fluorimetric confirmed. method also applied to dissolution profiles commercially available formulations solid oral administration sulfamethoxazole. empirical adjusted regression three-parameters plot method.