application of cold-induced aggregation microextraction based on ionic liquid for determination of trace amount of cadmium and lead in powder milk samples

background: cold-induced aggregation micro extraction based (ciame) based on ionic liquid was used as a rapid and simple method for determination trace amounts of cadmium and lead in milk powder by analysis with flame atomic absorption spectrometry (faas). methods: sample solution containing of cd2+ and pb2+ in dynamic range, phosphate buffer (ph = 9, 3 ml), diethyl dithiocarbamate (complexing agent), triton x-100, napf6 ,[hmim][pf6] (extraction solvent) were transferred into conical bottom glass tube. sample was kept in a thermostated bath and then ice bath a cloudy solution was formed. two phases separated by centrifugation. after removing of aqueous phase, il-phase was dissolved in methanol and diluted was injected to the faas by microsampler introduction. results: ils, containing imidazoliumcation and hexafluoro phosphate anion, [hmim][pf6](70mg), 200 mg napf6 ,0.01 mol.l-1 ddtc, 0.015% of triton x-100 obtained, ph 9 and centrifuge time 5 min (4000 rmp) was chosen. detection limit were obtained 0.12 µgl-1, 1.61µgl-1, rsd 0.95%, 2.2% and enrichment factor of 70, 67 for cd and pb, respectively. conclusion: ciame allows determination of cadmium and lead in real samples in a simple, rapid and safe method with only a small amount of ionic liquid was used. in comparison with the organic solvent extraction, ciame is much safer and the determination of species in high ionic strength samples is possible.