Compare IEnum Matches with Column in Data table and find Unique

I have Enumerable of Matches contains Values (Ex: 1, 2, 3, 4, 5, 6), Also In My Master Datatable I have column with Values (Ex, 5, 4, 2).

My requirement is to get the Unique Values (1,3 and 6)

I cannot loop as my data will be large in Realtime. Is there a quick solution to get unique values?