New research published in Science Advances, led by Yuan Yang, associate professor of materials science at Columbia Engineering, and collaborators at Lamont-Doherty Earth Observatory, demonstrates a novel technique for isolating isotopes.

Oxygen is a critical component in the positron emission tomography (PET) scans oncologists use to search for tumors. But not just any oxygen will work. While most oxygen atoms have eight neutrons, about 1 in 500 atoms has ten. Those extra neutrons are necessary for the PET imaging scans to work.

It's extremely expensive to isolate the slightly heavier oxygen atoms. A cubic meter of regular water (H2O) costs less than $2 from your tap. When the lighter oxygen atoms (and hydrogen) are removed, the heavier oxygen atoms that remain are worth closer to $30,000.

Researchers at Columbia figured out how to isolate heavier or lighter atoms—called isotopes—by dissolving the target element and salts in water before spinning that solution in a centrifuge. It's more effective, cheaper, and easier to scale than the current state-of-the-art techniques, which also use toxic chemicals that aren't necessary for the new method.