DETERMINATION OF TRACE-ELEMENTS IN MICROLITER SAMPLES BY SECONDARY-ION MASS-SPECTROMETRY

Trace elements in 5-mul sample solutions deposited on a substrate were determined by secondary ion mass spectrometry employing the internal standard method. A simple sample mount made of copper was devised to restrict the sample residue within a small area. The absolute detection limits of 22 elements ranged from 0.5 to 10(4) pg and their relative sensitivity factors were strongly correlated to the ionization potential of the elements. The matrix effect of various concomitants was relatively severe and the careful matrix matching or standard addition method was necessary for the analysis of practical samples. (C) 1994 Academic Press, Inc.