The paper must deal with very pure aluminum.
Probably yes, scientific papers generally use the purist reagents possible to attempt to give the most accurate results.
I am currently testing how "aluminum foil" grade Al holds up in nitric acid.
I added 1 mL fuming nitric acid (~96%) to .2 grams Al. After 15 minutes nothing has happened.
I also added 1.5 mL 68% nitric acid to .2 grams Al. Nothing has happened to it either.
IIRC, Al foil is ~98.5% pure, impurities being Fe and Si - which are added intentionally to make it slightly stronger.
[EDIT] I added a small amount of chloride ion (in the form of CaCl2
anhydrous) to the second test tube. Surprisingly still no reaction could be observed within 10 minutes.
I had to leave the lab and won't be able to check on anything for a few hours.