离子液体-超声波辅助萃取火焰原子吸收法测定油画棒中的可迁移微量Cd^(2+)

Ionic Liquid Based Ultrasonic-assisted Extraction Coupled with Flame Atomic Adsorption Spectrometry for the Determination of the Migration of Trace Cadmium in Oil Pastel

以离子液体为萃取介质,超声波辅助萃取油画棒中的可迁移微量Cd2+,以硝酸溶液反萃取后用火焰原子吸收法测定镉。考察了主要影响因素对萃取效果的影响。结果表明,以1-丁基-3-甲基咪唑六氟磷酸盐离子液体为萃取介质,溶液pH值为9.0、金属螯合剂用量为2.00 mL、离子液体的用量为2.00 mL、反萃剂为4.00 mL 1.00 mol.L-1硝酸、超声时间为5 min时,萃取率可达99%,富集倍数为25,除Cu2+、Pb2+外其它干扰离子对Cd2+的萃取影响不大。方法的加标回收率为96%～103%,相对标准偏差(n=11)为1.7%,检出限为0.016 mg.L-1。

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. （30 mL 1.00 mol · L^-1, ultrasonic extraction time： 5 min. Under the optimized conditions, the extraction efficiency of Cd^2＋ reached up to 99% , and the enrichment times was 25. The other metal ions made no effects on the extraction efficiency of Cd^2＋ except for Cu^2＋ and Pb^2＋. 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.