Chemical catalogue index
Depends on the journal and their layouts. Most will have a "Materials and methods" parts, this is where you write down which instruments and chemicals were used. At least in chemistry there are no common rules about how in detail this should be. You will read something like this very commonly:


  All commercially available analytical grade chemical reagents were purchased from Aldrich (St. Louis, MO) and used without further purification. 


But you can include more information here, like CAS number, catalogue number and so on.

Sometimes this section isn't present in the paper itself and you might include it in the supplementary information.

In the end it's important to include all the relevant data in a useful way and it doesn't really matter how you do it.