Gatekeepers and Treasurers
This chapter list the names of the gatekeepers, their duties was already described in chapter 9, verse 17-27. Although they had many duties, their chef duty is the guard the treasuries of the temple (9:26). It was a very important work, because all the treasures in Israel was stored in the storehouse in the temple. These treasures included the plunder taken in battle, and treasures dedicates by Israelites for the temple (v26-28).
The treasurers were assigned to take care of the treasuries. Working together with the gatekeepers, they keep the treasuries.
What are the treasures in the church today? I can think of many things but I like to focus on perhaps the most importance one: the teachings of Christ, the truth. A church needs gatekeepers to protect the truth. The enemies always is looking for gaps in the church to attack (2 Tim 4:4) the teaching of Christ, the job of the gatekeepers is to know the word of God well, and to guard the truth.