Hi @edfarnham
We had a similar customer question regarding tarnish but turned out their leads only had exposed copper. For reference, that post is found here.
The TI support download form found on this search (TI E2E support forums J-STD-002D solderability tests for component) may be what you are looking for or perhaps some kind of Jedec standard such as J-STD-002D may be something to look into, otherwise the manufacturer of each specific part should have information on their website regarding reliability and soldering such as this post, as some manufacturers purposely use a roughed lead frame with a NIPDAU | SN lead finish. This finish is less shiny but is better for solderability than smooth shiny leads.