Quantitative analysis of norfloxacin by 1H NMR and HPLC.

1H NMR and developed previously HPLC methods were applied to quantitative determination of norfloxacin in veterinary solution form for pigeon. Changes in concentration can lead to significant changes in the 1H chemical shifts of non-exchangeable aromatic protons as a result of extensive self-association phenomena. This chemical shift variation of protons was analyzed and applied in the quantitative determination of norfloxacin. The method is simple, rapid, precise and accurate, and can be used for quality control of this drug.