The gold and xp rewards from this quest have been hotfixed; however it still gives 250 rep every task.
In Zul'Drak you can get a quest at the Argent Stand called (Pa'Troll - Quest - World of Warcraft). This quest sets you out to complete 4 tasks around Zul'Drak.
Each task awards ~20,000xp and 250 Argent Crusade rep. The easiest task is (Lab Work - Quest - World of Warcraft) This task takes two minutes max and has you gather four materials from a lab. As you can see in the wowhead link you get ~20,000xp 250 AC rep and 6 gold.
After you complete the quest given by the alchemist you can drop 'Pa'Troll' and pick it back up at the stand. Once you do this the quest 'Lab Work' becomes available again.
Overall you can do the run between the lab quest and the run between the Argent Stand and the lab in about 1.5 minutes with about 40 completes a hour.
Here is a bit of math for you:
The experience per hour is pretty poor because there is no mob killing involved. However at lvl 80 this is a great way to gain Argent Crusade rep and grind gold.HTML Code:XP: 21150*(60/1.5)=846,000 Rep: 250*40=10,000 Gold: 6.2*40=248 Gold@80: 12.69*40=507.6
Just make sure you don't complete this quest or else you will only have the poor daily 'Troll Patrol' as a followup which has a harder task from the Alchemist and rewards far less.
I don't post here often and i've had this account for a very long time so any positive feedback would be great. I also searched the forum and didn't see this quest posted so if this is a repost I apologize.