Ok, I will try to help you, but it would be good if you could give me some more information (if possible). Just to tell you up front, I am a Board Certified Toxicologist, so reading tox screens is something I have to do daily. Also, right after undergrad before going onto more schooling, I did work for a clinical toxicology lab which performed a great deal of urine drug screening on a daily basis, so I actually used to do all of the testing as well, and still occasionally will I am want to verify something myself.
Other than your metabolic rate, hydration, age and health, there is one major factor in all urine drug screening, and that is: What type of method will they be using on your sample?
So do you know whether or not your urine sample will be sent out to a laboratory for analysis or will it be done on site where you give the sample? If you can let me know that, then I can give you much more specific information.
If you would prefer, you can email me and handle it that way:
[email protected]