[rolph]

sanitize a small sample then crack it open under cleanroom conditions to obtain an assumed pristine sample.

[edit] This is the full pdf below, if you look at page 2, you will see how they generated prepared and analyzed the sample

https://arxiv.org/pdf/2002.11688 [PDF]

and this is the meteoritic report for the subject:

https://www.lpi.usra.edu/meteor/metbull.php?code=95

the thing with structured peer review is that noone knows it all , and a team of specialists [review commitee] are much more powerful than a team of generalists, to the end of revealing any artefacts of procedure, or hair splitting levels of knowledge regarding metalo-organic chemistry that could explain abiotic process that would produce amino acid polymerization.