PI: Claire Chadwick
cgchadwi@uncc.edu

The Department of Geography and Earth Sciences is equipped with a Thermo Electron X Series Inductively Coupled Plasma Mass spectrometer (ICP-MS). ICP-MS uses a high energy plasma to break dissolved samples into their component atoms, and then into ions. The ions are separated by mass, and only ions of specific mass are allowed to reach the detector at any one time. The detector records the number of counts of each mass and compares this count rate to that of elements of known concentrations in a standard solution. This is used to convert counts on the detector to element concentrations in the unknown samples.

Rock, soil, and water samples can be analyzed using ICP-MS. Solid samples must be dissolved in a dilute nitric acid solution before being analyzed. Water samples are also acidified to prevent elements from coming out of solution.

ICP-MS can detect most elements between lithium and uranium with detection limits in the sub-ppb range, including most major elements, trace elements, and radiogenic isotope ratios. The accuracy and precision of analyses varies by element, and depends on the concentration of the desired element and the presence of interferences, i.e. isotopes, ions, or molecules with the same mass as the desired element.

The Department will be adding a CETAC LSX-200 Laser Ablation system to the ICP-MS in the near future. This will enable us to perform trace chemical analysis on solid samples, eliminating the need for time-consuming sample digestion and allowing us to analyze specific locations on a sample.