Radio-LC-MS for the characterization of 99mTc-labeled bioconjugates

Bioconjug Chem. Jan-Feb 2000;11(1):113-7. doi: 10.1021/bc990111r.


This report describes the first example of using radio-LC-MS for determining the composition of (99m)Tc radiopharmaceuticals at the tracer level. The in-line radiometric detector is a useful addition to a standard LC-MS and provides direct correlation between the MS data and the radioactive species in a radiopharmaceutical kit. Complexes [(99m)Tc(HYNICtide)(tricine)(L)] (RP444, L = TPPTS; RP445, L = TPPDS; and RP446, L = TPPMS) were prepared using a decayed generator eluant. All the ternary ligand (99m)Tc complexes show the expected monoprotonated molecular ions, (M + 1)(+), and diprotonated molecular ions, (M + 2)(2+). The LC-MS spectral data support the proposed structure and are consistent with those obtained for their corresponding (99)Tc analogues. Ternary ligand complexes [(99m)Tc(HYNICtide)(tricine)(L)] (L = ISONIC-HE and ISONIC-Sorb) are neutral, and the molecular weights are also lower than that of RP444. Using a fresh generator eluant (24 h prior elution), only 1-2 mCi of (99m)Tc [(7 x 10(-)(12))-(1.5 x 10(-)(11)) mol of technetium complex] are required to obtain a reasonably clean mass spectrum. Radio-LC-MS is a quick and accurate analytical tool for characterization of (99m)Tc radiopharmaceuticals at the tracer level.

MeSH terms

  • Chromatography, Liquid / methods
  • Mass Spectrometry / methods
  • Organotechnetium Compounds / chemistry*
  • Peptides, Cyclic / chemistry
  • Radiometry / methods
  • Radiopharmaceuticals / chemistry*


  • 99mTc(HYNICtide)(tricine)(TPPTS)
  • Organotechnetium Compounds
  • Peptides, Cyclic
  • Radiopharmaceuticals