Determination of Multi-Element Composition and Mass of Single Nanoparticles in Liquids and Air
Single particle (SP) ICP-MS is routinely applied for quantitative determination of size and number concentration of metal-containing nanoparticles at low, environmentally relevant levels. Due to limits of current instrumentation, SP-ICP-MS has primarily been applied to relatively simple systems containing of one- or two-element particles. In particular, most ICP mass spectrometers use quadrupole or sector-field mass analyzers, which sequentially measure the intensity of individual elements (mass-to-charge values). Because the transient signal arising from the vaporization and ionization of a single particle is very fast, these mass analyzers only have time to step through one or two elements within the duration of the particle detection event. In contrast, time-of-flight (TOF) mass analyzers – such as that used in the TOFWERK icpTOF – simultaneously measure all elements, and are capable of recording multiple complete spectra during the detection of a single particle. This enables SP-ICP-MS analysis of multi-element particles of unknown composition.
This poster from ICEENN 2016 (Golden, CO, USA) demonstrates how the TOFWERK icpTOF can be used to quantitatively characterize complex multi-element particles in both liquids and air.