You can use Map_operation transform as given here
Map_Operation transformation in Data Services
or
Create two tables.
Say tbl_source and tbl_target. Make tbl_target as a permanent table
Step 1 : Left join these two tables on common key and filter the non matching records and store the result back into the target table.The non matching records from source are the new records
Step 2: Place a script with SQL function to delete the matching records in target table on common keys