Put this function in a cell (B23), copy it the amount of columns you have over, and then the amount of rows down.

=IFERROR(MID(B2,1,FIND(" min",B2)),0) + IFERROR((MID(B2,FIND(" sec",B2)-2,2)/60),0)
Convert it back after you have a calculation.

Note: This converts everything, in a makeshift way, to minutes.