Duplicates folder show items from deleted collections
dstillman
Zotero Team
This discussion was created from comments split from: Prevent duplicate during import.
Upgrade Storage
Zotero is not the optimal reference manager for importing records from related (but different) search database queries which may output many shared records. Dealing with merging or deleting large numbers of duplicates is a tedious record-by-record click and merge process (no automated batch capabilities). IMO, a citation manager should handle duplicates much more transparently. Zotero also needs a database analysis feature (how many duplicate and or unique records exist? per library, per collection?). Those stats can be informative.
You're misunderstanding how collections work. Simply deleting a collection doesn't delete the items — they may exist in other collections and regardless will continue to exist in the library root. If you want to actually delete the items, you need to choose "Delete Collection and Items".
https://www.zotero.org/support/collections_and_tags#the_zotero_collections_model