Highly sensitive and selective spectrofluorimetric determination of nitrite in food products with a novel fluorogenic probe

• A novel fluorogenic probe was applied to nitrite determination.
• The novel probe reacted with nitrite based on a new mechanism.
• The novel probe is highly sensitive and selective, stable and less toxic.

A simple, sensitive, selective and convenient spectrofluorimetric method for detection of nitrite has been successfully developed. This method is based on the highly efficient and specific reaction of nitric oxide with a dihydropyridine derivative to form a highly fluorescent pyridine derivative, in aqueous solution. Under optimum conditions, excellent detection linear range was achieved from 0.2 to 4.5 μmol L−1 with a detection limit of 0.02 μmol L−1 (S/N = 3), lower than or comparable to most of other spectrofluorimetric methods. The relative standard deviation for ten determinations of 2.0 μmol L−1 nitrite was 1.0%. The proposed method has been applied to determine nitrite levels in food products with recoveries of 93.3%–103.5%.