Chest/Tri and Back/Bi Days?

[d'Anconia]

I used to do a routine that looked something like this:
Chest/Tri
Back/Bicep
Legs
Shoulders

But then a friend of mine told me that doing triceps on the same day as chest wasn't going to build my triceps up as much because (in my case) I do things like bench or incline first in the workout and then more tricep-isolated exercises later in the workout. According to him the triceps won't build up as much because early in the workout they are being used as a secondary muscle and that means that later when they are worked as a primary muscle that they are already fatigued (or something like that) and somehow that menas they won't gain mass that well.

Same goes for a back/biceps day

Can anyone support or oppose this claim? Because I loved doing chest/tri and back/bi workouts.

[HILL]

i prefer to do chest and bi's this is because tri's is a secondary muscle when doing bench press in chest and i feel that once ive done my chest my triceps are exhausted and i cant train them to their full potential but some people ive spoken to and in articles ive read state that once youv done chest you have already done half your tri's so you may as well finish them off if you get what i mean so i think its personal preferance

[Barker]

Yea iits personal preference for them. I prefer to train tris with my back and bis with my chest for the reasons you mentioned. I have found this split has added more mass to my arms and I can train those muscles harder on separate days. This is not to say you can't train chest/tris & back/bis on the same day. This is just what works better for me. But in reality, just do what you want to.