Spectrofluorometric determination of hesperidin by manual and flow-injection methods

A reliable and highly sensitive method for the determination of hesperidin is described. It involves the formation of a highly fluorescent complex between hesperidin and aluminium (III) in a micellar medium. There is a linear relationship between fluorescence intensity (lambda(em) = 496 nm, lambda(ex), = 391 nm) and hesperidin concentration over the range 5 x 10(-7) - 2 x 10(-5) mol L-1. The detection limit is 79 mu g L-1. The method can easily be adapted to a flow system using a three-channel manifold, the peak height being proportional to the hesperidin concentration over the range 1 x 10(-6)- 1 x 10(-4) mol L-1. Manual and flow-injection procedures have been successfully applied to the determination of hesperidin in orange peel and orange juice.