Is there a way to determine if a removable drive is a USB drive?

What you seem to actually be asking is "is there a way to determine if a given drive is a removable USB drive?" Generally speaking, the answer is probably no. The concept of "removable" drive is a bit too abstract to really deal with effectively in software. Is an ATAPI drive in an external USB case a removable USB drive? What about SCSI drives in hot-swappable RAID trays? What about a firewire attached drive that is inside the computers case?