Environmental analysis by inductively coupled plasma spectrometry: an interesting journey at Queen’s University

A review of environmental analysis work carried out by the Beauchemin group using inductively coupled plasma (ICP) mass spectrometry (MS) and optical emission spectrometry (OES) over several decades is presented. Using a continuous online leaching method (COLM) with real-time detection by ICPMS allows measurement of the bio-accessibility of elements and can also be used to infer their source. Indeed, unlike batch methods typically used to measure bio-accessibility, the temporal profiles generated with the COLM can readily reveal if different sources of elements are present through several peaks in the temporal profiles. Common sources of different elements can also be revealed through correlations between their temporal profiles. Similarly, Pb isotope ratios obtained as the slope of the linear correlation between the temporal profiles of two Pb isotope can reveal the presence of Pb from tetraethyllead previously employed as antiknock agent in gasoline. Electrothermal vaporization (ETV) coupled to ICPOES allows for the quick analysis of solid samples, eliminating the need for time-consuming digestion. It was successfully applied to the quick quantitative analysis of a variety of environmental samples. This includes clays and soil samples collected during geochemical exploration to locate undercover ore deposits. There is also potential for the direct speciation analysis of solid samples using ETV-ICPOES.