Yes, 2 ounces is more than plenty. Collectors do have a habit of asking for more than 2 ounces for many reasons one is trying to scare you because they know what goes on they just are limited in what they can do to stop it. Another is that if they ask you for less people already "short" them so they ask a little more to make sure they get what they need. A split sample can be done with 1 & 1/2 ounces or 45 cc or mls because you need 15 cc for the immunoassay, 15 for GC/MS and then if you want to challenge a positive at another lab (good luck because for some strange reason these requests usually go unheard cough conspiracy cough) 15 more for a second GC/MS. The split sample is also sometimes called the B sample. They won't run immunoassay on the retest, it's pointless. Some collectors will fill both A & B vials with 30 ccs to make it easy. If asked for more, ignore them with confidence, give them the 60 ccs with a smile, and if they try to BS you play it cool like, "well try and see if that's enough looks like you got plenty" or something similar and of course they will. I had one ask for about 8 ounces and I laughed as I opened the bathroom door. On average you make 30 cc of urine an hour so that collector was expecting me to hold it for 8 hours??? Get real.

If you get a clean donor go with 60 ccs also.