What are the possibilities of determining the presence of a certain
chemical in a plasma or urin sample?
Are there institutions that provide a cheap scientific service of such
to citizens, with respect of privacy?

It's a matter i can't addres my hospital, of physician with.
I would like to avoid public health institutions and go with public or
privat scientific institutes.

There is a rare test for this supstance to which i can't revert to,
because i would like to avoid indicating the supstance. I would rather
like to get a full readout of the sample's components. (So, I was
thinking something in tearms of mass spectrometry of the sample?)
Is it possible to request a full composition readout from someone on
privat basis?
What are all the possibilities?

Which institutions provide such a service, and which could i contact.