It may be easier to use the event EVENT_INVENTORY_SINGLE_SLOT_UPDATE and check for isNewItem, which is true when the item is added to your inventory.
Lua Code:
function InventorySingleSlotUpdate(eventCode, bagId, slotId, isNewItem, itemSoundCategory, updateReason)
You can then use some more functions to get all informations about the item (copied from the wiki):
Lua Code:
GetItemLevel(integer bagId, integer slotIndex)
Returns: integer level
GetItemTrait(integer bagId, integer slotIndex)
Returns: ItemTraitType trait
GetItemInfo(integer bagId, integer slotIndex)
Returns: textureName icon, integer stack, integer sellPrice, bool meetsUsageRequirement, bool locked, integer equipType, integer itemStyle, integer quality
GetItemType(integer bagId, integer slotIndex)
Returns: ItemType itemType
As far as i know, this is the only way to get itemType and traitType from looted items.