Spec-RAM LC: A new HPLC solution for Pb-212
16/10/2025
No waiting, no fraction collection, no manual data handling
LabLogic is pleased to introduce a new gamma spectrometer for HPLC analysis of 212Pb radiopharmaceuticals. The Spec-RAM LC delivers immediate results, and can differentiate the signals from 212Pb and its daughter isotopes. It is a benchtop instrument that can be used with any HPLC system, including LabLogic’s Logi-CHROM. The instrument is controlled by our Laura Radiopharma software, which uses time-resolved gamma spectrometry and innovative peak-finding tools to fully automate the measurement of radiochemical purity (RCP) for 212Pb radiopharmaceuticals.
This new development eliminates waiting decay of daughters, fraction collection, and manual data handling to deliver fast, accurate RCP measurements.
A true measure of radiochemical purity
When using traditional online radio-HPLC detectors based on NaI, all gamma-emitting isotopes are counted in the HPLC eluent and so it is difficult to accurately assess RCP. The Spec-RAM LC allows immediate and precise measurement by isolating the signal from the parent isotope.
Fig 1: RCP measured at 83% using existing methods such as fraction collection and gamma counting.
Fig 2: RCP measured at 99% using the new Spec-RAM LC.
Did you catch our latest webinar?
In our recent webinar where we unveiled the Spec-RAM LC, we outlined the challenges of working with a novel isotope such as 212Pb and how the new gamma spectrometer helps deliver practical QC for alpha therapeutics.
212Pb is a beta-emitter but its alpha-emitting daughter 212Bi means it has great potential for alpha therapeutics. Because of the high energy of alpha emissions when decaying, recoil and radiolysis result in off-target toxicity and impurities making QC testing critical. With a half-life of just 10.6 hours, such tests must be done quickly.
In the 238 keV energy window, there can be contributions from 212Bi, 208Tl, and 212Pb, but for RCP, only the parent 212Pb is measured. This can be particularly difficult to do using a traditional gamma counter because of the daughters scattering, creating a signal inside the 212Pb energy window, even when there is no 212Pb present in the HPLC eluant. Only a detector with sufficient resolution such as the Spec-RAM LC can discriminate between the 277 keV gamma from 208Tl and the 238 keV gamma from 212Pb.