Spectrofluorimetric determination of tin in canned foods

A simple and sensitive spectrofluorimetric method for the determination of tin as its complex with 1-(2-pyridylazo)-2-naphtol (PAN) in a mixed micellar medium was developed. The mixture of a non-ionic surfactant, Triton X-100 and an anionic surfactant, bis(2-ethylhexyl) sulfosuccinate (AOT) was used as a suitable micellar medium for solubilizing of complex and ligand and also for enhancing the fluorescence intensity of complex. In the optimum experimental conditions the maximum excitation and emission wavelengths of Sn-PAN complex were 300 and 360 nm, respectively. The calibration graph was linear in the range of 0.01-0.8 μg ml−1 with a correlation coefficient of 0.9991. The detection limit was found to be 2 ng ml−1. The relative standard deviation of the method for the determination of 0.1 μg ml−1 tin was calculated to be 0.74%. The interferences caused by the presence of a number of common cations and anions were studied. Finally, the method was successfully applied to the determination of tin in various canned products.