Characterization of inductively coupled plasma mass spectrometry with segmented-flow injection

Abstract

The figures of merit for inductively coupled plasma mass spectrometry with flow injection were determined for a range of elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, As, Se, Mo, Cd, Sb and Pb) using three different carriers, water, air, and air-segmented water, for which injections were made within air segments. Compared with flow injection into water, narrower and symmetrical peaks were observed with either the air or air–water carrier. The last two carriers provided twice the sample throughput obtained with water, and more reproducible injections. Peak height sensitivities were enhanced by a factor of 2–5 using the air or air–water carriers, but part of this enhancement was due to increased solution transport efficiency when air was present in the carrier. When water as carrier was replaced by air–water, detection limits improved by a factor of 2–6 for V, Cr, Mn, Fe, Ni, Cu, As, Se, and Cd, remained about the same for Al, Co, Sb, and Pb, and were degraded by a factor of 2 only for Mo. The water and air–water carriers showed similar memory effects, reduced in comparison with the air carrier. Overall, flow injection into the air–water carrier resulted in the best precision, sensitivity, and detection limits for the greatest number of elements.