Back + biceps yes or Chest + triceps....but
not delts before biceps 
You can do whatever you want and experiment on yourself. If you are a personal trainer and giving clients this advices you are incorrect.
Not sure why you would train delts and biceps in a split but if you did enough presses your tri's would get worked. In any event you would train the larger shoulder and delt area first because it takes more energy to do and you train it heavier.
If you trained shoulders and arms (bi's and tri's) you would train shoulders (delts) first and end with the arms. Otherwise your arms would be too fatigued to properly train the shoulders.
In a full body workout train the large muscle groups first unless you are focusing on bringing up a weak bodypart. This is because the large groups requite more energy to train.
For example: Legs, chest, back, shoulders, arms, calves. Legs take the most energy to train so you do them first. Bodybuilders who train legs last tend to skip legs as they are too tired.
However, if you wanted to bring up your arms you could train them first but understand this will negatively impact your leg training and the following pressing and pulling movements.
Steve Reeves would train his legs last but he had great legs and wanted to emphasize his upper body shoulder region.
