Subbing With Frozen???

I have asked several questions regarding subbing and frozen urine. So, thanks in advance for the help.

Here's the deal, I have subbed 4 times using frozen samples from 2 different friends and passed all 4.

Today I used the last 2ozs for my PO but this is urine that has been frozen and thawed 2 times. It was only unfrozen at room temp for a total of 2 hours, however it smelled stronger than the last 2 uses. There were no visable differences, but could that odor be detected and identified as "old"?

If anyone has a logical answer, it is truly appreciated.

I was just thinking and the urine didn't have any ammonium smell. Just a stronger urine smell.

Smells that shouldn't be there are to be noted by collector such as bleach, gasoline, lysol, etc. and then still submitted.

2 hours, I think you'll be fine.

Thanks FBR. You know way too much about all this stuff.

So, is that possible for the 3rd use of the same batch of urine to smell stronger than the first 2?