High-performance thin-layer chromatography method for monitoring norfloxacin residues on pharmaceutical equipment surfaces

This paper presents a high-performance thin-layer chromatography (HPTLC) method with direct fluorescence measurement for the determination of norfloxacin. The method was validated for the monitoring of norfloxacin residues on stainless steel surfaces at the allowed limit of 10 mg of norfloxacin per square meter. However, it can be adapted for lower amounts of residues owing to the low detection limit of norfloxacin (about 5 ng) and can also be used for other surface materials. Test solutions were analyzed by the new HPTLC method and the known HPLC method for comparison. Accuracy and precision of the new HPTLC method, with a subsequent quantification by densitometer or video system, are comparable with those of the HPLC method.