| A flame atomic absorption spectrometric method coupled with ionic liquids based ultrasonic assisted extraction was developed for the determination of the migration of trace cadmium in oil pastel.The main factors affecting the extraction efficiency,such as pH value,amount of metal chelating,ionic liquid and nitric acid,ultrasonic extraction time,metal ions interference and chain length of ionic liquid were studied.The optimal conditions were as follows：pH value：9.0,metal chelating amount：2.00 mL,amount of ionic liquid：2.00 mL,amount of nitric acid：4.00 mL 1.00 mol?L-1,ultrasonic extraction time：5 min.Under the optimized conditions,the extraction efficiency of Cd2+ reached up to 99%,and the enrichment times was 25.The other metal ions made no effects on the extraction efficiency of Cd2+ except for Cu2+ and Pb2+.The recoveries for the method varied from 96% to 103% with relative standard deviation（n=11） of 1.7%，and the detection limit was 0.016 mg?L-1. |