The issue is the comma in your text. You could start by removing this and splitting the time into mins and seconds in two columns. Example row 1 is headers, A = Time, B = Mins, C = Seconds.
With your first time in A2 put this in B2 =LEFT(A2,FIND(",",A2)-1) and this in C2 =RIGHT(A2,LEN(A2)-FIND(",",A2))
These formulae will split the time at the comma.