Pair biceps with chest, triceps with shoulders, and work back solo.
I really like this type of routine. I don't think it is a good idea to focus one day of training on just arms. I think you should consider incorporating military presses into your shoulder routine. Its a great compound lift.
I have had good success with this routine:
Monday - Chest / Biceps
-4 sets flat bench
-4 sets incline dumbells
-4 sets cable crossovers
-4 sets dumbell curls seated on incline bench
-4 sets preacher curls - barbell
-finish off 3 sets of cable curls
Tuesday - Legs
-4 sets squats
-4 sets leg press
-4 sets stiff legged deadlifts
-4 sets hamstring curls
-4 sets calf raises
Wednesday
-Rest Day
Thursday - Shoulders / Triceps
-4 sets barbell military press
-4 sets lateral raises
-4 sets seated dumbell military press
-4 sets cable "front raises" - I don't know what its called. Like lateral raises only in front of you. You can use dumbells, but this makes my shoulders pop
-4 sets of dips
-4 sets of skull crushers
-4 sets of cable tricep extensions
Friday
-Rest Day
Saturday - Back
-4 sets deadlifts
-4 sets pullups
-4 sets lat pull downs
-4 sets of cable rows
-4 sets shoulder shrugs
Sunday
-Rest Day
--You could do back on Friday and then take the weekend off too. My tri's are spent on shoulder day, and my biceps are spent on Chest day. Also, I get a bit of a workout on my Tri's on shoulder day from the presses, and on back day, I can feel it a bit in my biceps on the pull downs and cable rows.
I hope I don't sound like I am telling you what to do. I am just giving an example of what works for me. I believe it is a great split, and you can substitute different lifts that work for you on each day.