A simple and highly sensitive method is described for the spectrophotometri
c determination of saccharin. The method is based on the bromination of sac
charin to form N-bromo derivative, which reacts with potassium iodide to li
berate iodine. The iodine liberated is then reacted with leuco crystal viol
et and the crystal violet dye Formed shows lambda(max) at 593 nm. The colou
r system obeys Beer's law in the range 0.05-0.5 mu g ml(-1) of saccharin an
d has apparent molar absorptivity of 2.93 x 10(5) dm(3) mol(-1) cm(-1). The
method is free from interference of common diverse ions and many of the in
gredients commonly found in food products and has been satisfactorily appli
ed to the determination of saccharin in food and pharmaceuticals.