In any given room, even the most sterile scientific clean rooms, there are
dust particles in the air and coating every surface.
If allowed to go uncleaned, the dust will accumulate to eventually cover
every surface. But what exactly is the dust in the air and on our tables
and shelves? A chemistry research team
at the Ohio State University, using a new kind of sensor, has isolated and
measured the composition of unique dust particles in their laboratory.
Led by James Coe, professor of chemistry, the Ohio State University
researchers identified 63 dust particles, each containing its own composition of
ingredients. They found the most common ingredient of indoor dust was
organic matter, originating from either a plant or animal. While not all
specifically identified, this matter includes skin particles, dander,
pollen, and many others.
The second-most common ingredient is quartz, also the second-most abundant
mineral on Earth's crust after feldspar. Both quartz and organic matter
were found in over half of all dust particles classified. Other
ingredients found were man-made chemicals created from air pollution,
fertilizers, and construction materials like gypsum.
The sensor utilized by Coe's research team has a metal mesh, in which
particles get stuck. An infrared light is used to pick up the complex
details in each dust grain. The mesh helps to separate particles by size
which can isolate the ones small enough to enter people's lungs. The
potential health care applications are enormous.
The sensor was originally built to create plasmons, mixtures of conducting
electrons and photons. These boost the light intensity passing through the
metal mesh, letting scientists record,
in detail, the infrared light spectrum. Any material inserted in the
sensor could be analyzed for its unique signature on the spectrum.
Then dust entered the sensor, clogging the mesh. The scientists then
realized the sensor could be effectively used at analyzing airborne dust
particles. Coe's students competed to analyze individual dust particles in
the air, and found 63 overall. Their research has been published in the
recent issue of The Journal of Physical Chemistry C.
Link to published article: http://pubs.acs.org/doi/abs/10.1021/jp205383h