Determination of Manganese,Copper,Lead,Zinc,Chromium and Cadmium in Phosphate Rock by Inductively Coupled Plasma Mass Spectrometry

A method for the determination of manganese,copper,lead,zinc,chromium and cadmium in phosphate rock by inductively coupled plasma-mass spectrometry(ICP-MS) is established. The ICP-MS instrument operating parameters were optimized. The mass spectral interferences were eliminated by selecting ⁵⁵Mn,⁶⁵Cu,²⁰⁸Pb,⁶⁶Zn,⁵²Cr and ¹¹⁴Cd as the analytical isotopes. And Rh was selected as the internal standard to compensate the analytical signal drift. Under the optimized conditions with a HNO₃-HClO₄-HF digestion system,the recoveries for these elements were 98.0%~102.0% with a precision of 0.99%~1.98% RSD(n=9).The proposed method has been applied to the determination of these trace heavy metal elements with satisfactory results.