Can you purify a metal oxide with a laser?
this is an interesting question and I will answer it a bit differently.

There is a well known analysis technique in materials chemistry called ICP-MS (Inductively Coupled Plasma Mass Spectrometry) where you have a sample, and using an inductive electric field, the plasma of the sample containing ions of the elements present is created. This is then passed thorugh a mass spectrometer to know the elemental composition of a material synthesised. It is one of the best known techniques for elemental analysis.

However, the idea of using ICP-MS like technique for purification of metal oxides is novel to me. Instead of induction to introduce electric field and rip apart the electrons from the atoms, you can achieve the same using a laser. The rest idea is same.
However, you can try it, and in case you design an instrument and get a publication for the same, kindly let me know here. I will look forward to it.

References:

https://en.wikipedia.org/wiki/Inductively_coupled_plasma_mass_spectrometry


Kindly contact me in comments in case you have any questions.
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