The tithe separated pre-Terumah from the sheaves, is free from any obligation for Terumah but requires removal of the Terumah which is removed from Tithes - Terumat Maaser: Shabbat 127b; Eruvin 31b; Pesachim 35b
Terumah which is removed from Tithe [Terumat Maaser], which was separated from its produce before Terumah was taken from that produce: Shabbat 127b, 128a Punishment for removing Secondary tithe [Maaser Sheni] before the Primary tithe [Maaser Rishon]: Temurah 4a
A fine for separating the Maaser Rishon tithe before the obligation for tithing began: Beitzah 13a-b
Maaser Rishon shelo nitlah Terumato - Laws of Tithe which has not had Terumah Removed Yet
Terumah should be removed before other tithes, based on the biblical wording: Eruvin 37b Retroactive separation of Terumah / Other Tithes [Bereirah]: Eruvin 36b-38a; Yoma 55b-56b; Succah 23b-24a; Bava Metzia 11a-b
Declaring that the Terumah and other tithes will be taken from various parts of the bale itself: Eruvin 37b
Requirement of separating tithes once the Maaser Rishon tithe has been separated: Beitzah 13a-b