Flow Injection Technique for Determination of Thallium, Lead and Bismuth in Nickel-Base Alloys by Inductively Coupled Plasma Mass Spectrometry

A flow injection (FI) technique has been applied to the trace analysis of metal samples using inductively coupled plasma mass spectrometry (ICP-MS). Parameters such as carrier flow rate, injection volume and sample concentration has a great influence on the sensitivity, precision and analysis time of the FI/ICP-MS. A small volume (240μl) of nickel-base alloy solutions containing up to 0.75% (m/v) was introduced into an ICP-MS instrument by the flow of carrier solution. The optimized procedure was applied to the determination of Tl, Pb and Bi in standard nickel-base alloys of the National Institute of Standards and Technology. The result was compared with that of the continuous sample nebulization method. The FI method gave improved precision as well as high sensitivity. The precision ranged from 2.0 to 8.2 (RSD, %) for the elements containing 0.25-11.7ppm. Detection limits were 0.001-0.04ppm.