A sensitive resonance light scattering (RLS) veloped based on the interaction of lead with an excess method for the determination of lead has been de- potassium iodide to form [ PbI4 ] 2 - complex, and then the [ PbI4 ] 2- reacts with acridine red to form an ion-association complex in a 20 mmol/L HzSO4 so- lution. The RLS intensity at λmax 420 nm is proportional to the concentration of Pb ( Ⅱ ) in the range of 5.16×10-8 -8.0×10-7 mol/L,and the detection limit for Pb( Ⅱ ) is 1.55×10-8 mol/L. The method has good sensitivity, mild reac...