I'm trying to poll the arp table from a backbone switch but i want to understand which records are up. I just want to know if there is a specific time for the switch to keep a record on the arp table even if it doesn't get any traffic from an IP address.
I assume you are in fact asking about the switch
MAC address table (the real name according to 802.1D-2004 is actually
filtering database but it is never used in practice).
As you can infer from @Cown comment, this is dependent of the switch model and can vary from minutes to hours. It may also be configurable.
You will have to check the documentation and the current configuration of your switch to be able to answer your question.
Also, each entry is (by the very purpose of the table) associated with a port, and on most switches the entry will be immediately removed from the table if the port goes down.