DustScanAQ uses Scanning Electron Microscopy coupled with Energy Dispersive Spectrometry (SEM-EDS) to investigate sample morphology and chemistry. SEM-EDS allows particles to be examined at magnifications up to 30,000x and can produce high resolution images of dust samples to provide greater morphological detail than would be obtained using optical microscopy alone.
SEM-EDS can also produce false-colour element maps of many common elements including, but not limited to, oxygen, magnesium, aluminium, silicon, calcium and iron. These maps can be used to examine the chemistry of individual particles, which can frequently be scarce in nature and is therefore particularly useful in environmental forensic investigations.
Detailed elemental analysis can be achieved by using Inductively Coupled Plasma – Mass Spectrometry (ICP-MS). Samples are filtered onto mixed cellulose ester (MCE) filters in preparation for analysis. ICP-MS produces quantitative data on the concentration of a wide range of elements and is particular useful when looking for contaminants such as heavy metals. The data from ICP-MS are typically reported in µg/g or expressed as a weight percentage. These data can be plotted to show dust sample chemistry in comparison with reference materials.
Some non-metallic elements, such as oxygen, silicon and sulphur cannot be analysed by ICP-MS as these elements are dissolved during sample preparation. However many elements not reported by ICP-MS can be readily identified using SEM-EDS. Consequently, it may be appropriate to carry out both elemental and chemical analysis.