your arms get worked with almost every (if not every) upper body workout. I would suggest doing chest/tri's back/bi's use intensity techniques like drop sets, 21's, cheat curls followed by strict db curls, forced reps, etc. hit'm hard and furious, and go home and eat. it should not take any longer than 20-30 minutes to work either biceps or triceps, if it does your spending too much time.