having just stumbled upon this VICE article - hxxp://www.vice.com/read/tinkle-tweaking-v18n6 - made me further consider and reflect upon this...
many substances are renally excreted in significant amounts as unchanged parent compound or various active metabolites.
extraction in most cases should be easy and straightforward.
so... what are your thoughts on this?
i don't see myself collecting my urine in HDPE barrels for setting up urine extraction labs, or giving myself a urine enema any time soon, but still..