SIMULTANEOUS DETERMINATION OF TWELVE HEAVY METALS IN SEDIMENT BY ICP-MS

Three digestion methods were investigated to compare their effects on the determination of twelve heavy metal elements(Cr,Co,Ni,Cu,Zn,Mo,Cd,Sn,Hg,Tl,Pb,U) in certified reference materials.The results showed that the efficiency of microwave digestion was better than the other two digestion methods.A mixed digestion system of HNO3-HF-H2O2 was used with a better digestion effect.A method based on inductively coupled plasma-mass spectrometric(ICP-MS) analysis was established for the determination of the twelve heavy metals in sediments.Good linearity of the calibration curves was obtained for these elements(r=0.9998—1.0000).Detection limits for these twelve elements were in the range of 2.2 ng · g-1 to 66.0 ng · g-1,and the recoveries of Rh and Re elements were in the range of 91.2% to 106.9%.The MESS-3 standard reference material was determined with this method,and the results of twelve elements were in good agreement with the reference values.The RSD varied from 1.2% to 5.7%,which showed that the method had high precision.