an investigation on heavy metals bio-sorption by azolla filiculoides in the international anzali wetland

the ultrasound assisted emulsification microextraction (usaeme) method followed byinductively coupled plasma-atomic emission spectrometry (icp-aes) was used for preconcentration anddetermination of bismuth (bi), indium (in) and lead (pb) in the plant azolla filiculoides lam. calix [4] pyrrole was used as a chelating agent and tetrachloroethylene was selected as extraction solvent. the main parameters of the usaeme method were optimized by using response surface methodology (rsm). the optimal conditions were as follows: 130 μl for volume of extraction solvent, 4 min for sonication time, 6.75 (w/v %) for salt concentration, 890 mg/l for concentration of chelating agent and 7.5 for ph. the calibration graphs were linear in the range of 1-1500 μg/l for bi and in, and 1-1000 μg/l for pb with the determination coefficients (r2) of 0.9983, 0.9974 and 0.9997, respectively. the limits of detection (lods) for bi, in and pb were 0.57, 0.76 and 0.84 μg/l, respectively. under the optimal conditions, the method was successfully applied to the determination of bi, in and pb in azolla filiculoides lam. tissues in anzali wetland and satisfactory relative recoveries (94–97%) were achieved.