I have found a fudge. If you ctrl+f for find and replace, then type Mr/Mrs or whatever and replace with a space. Be aware that if you do Mr first, you will take the Mr out of the Mrs to leave an S, so better do Mrs first (if that makes sense). You can do replace all, so will only have to do it for as many titles as you have. (Hopefully it is Mr. so you won't take Mr out of any names... ).
Then Sort A to Z. Can do this by right-clicking on cell and going to Sort. Or Sort and Filter button on Menu bar.
Hope that works... There is probably a better way, but I can't find it in the Sort menu..