Abstract :
A spectrofluorimetric determination of sulfite based on the co-quenching effect of sulfite and formaldehyde on the fluorescence of a red-region dye, tetra-substituted amino aluminum phthalocyanine (TAAlPc), is described. The relationship between the fluorescence quenching of TAAlPc and the concentration of sulfite is linear over the concentration range of 8240ngml-1 under optimum conditions. The 3sigma limit of detection is 3ngml-1 and the relative standard deviation of six replicate measurements is 3.5% for solution containing a 160ngml-1 sulfite. The possible reaction mechanism is also discussed. This method has been successfully applied to the determination of sulfite in VK3 injections and sugar.
