In basic medium

acetone can react with CIO

-

and H

2

O

2

to produce chemiluminescence (CL) emission. The halide ions were found to sensitize the acetone CL reaction. The mechanism of the halide sensitization effect has been briefly discussed. Based on this effect

a novel CL method for the determination of iodide ion was proposed. The experimental results illustrate that the detection limit is 2.0×10

-11

g/ml I

-

and the linear range is 4.0×l0

-1

g/ml to 3.0×10

-7

g/ml. The effect of some foreign ions was also studied.