My organization currently performs the analytical side for an international organization specializing in the verification of drinking water units for extractable (sometimes called leachable) components from the units manufacture.
Depending upon your application there are a number of NSF protocols to follow for the extraction. For drinking water, you are generating synthetic drinking water, challenging the system, and then analyzing the water from the challenge. If your application is within the midical industry, then you should look at adjusting the extraction fluid from synthetic drinking water to whatever fluid the unit will be used with.
On the analytical side doe oeganics you typically you use GCMS, both volatiles and semivolatiles by GCMS (USEPA methods 524.2, 525, and 625) as well as at time HPLC when the known chemistry of the material would indicate the potential for compounds to leach from the unit that are not ameniable to GCMS. For metals we are using ICPMS following USEPA method 200.8. The challenge is first to get a complete breakdown of the material the unit is made up of (100.0% composition of parts in contact with the fluid) so you know what to look for. This is typically a fairly arduous process to simply sort out everything that went into the unit. This list is then sent over to a toxicologist who then determines if any additional testing is needed beyond the GCMS and ICPMS techniques.
On the instrument side, if this is in fact NSF type testing, there is a significant challenge in achieving the levels of detection for their requirement (NSF).
If this is pharnaceutlcal; I would be surprised if there are not very specific requirements for the for how the leaching is performed, and what analytes you need to monitor.