Radio-LC-MS for the characterization of 99mTc-labeled bioconjugates.
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.
Liu
S
S
DuPont Pharmaceuticals Company, Medical Imaging Division, North Billerica, Massachusetts 01862, USA. shuang.liu@dupontpharma.com
Ziegler
M C
MC
Edwards
D S
DS
D002853:Chromatography, Liquid / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D015609:Organotechnetium Compounds / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry; D011874:Radiometry / Q000379:methods; D019275:Radiopharmaceuticals / Q000737:chemistry*
C400057:99mTc(HYNICtide)(tricine)(TPPTS); D015609:Organotechnetium Compounds; D010456:Peptides, Cyclic; D019275:Radiopharmaceuticals