Per-isotope SOP · GABI Nova
The radio-HPLC chromatogram looks different per isotope. Per-isotope: which probe is fitted, which column / mobile-phase combination is used, where the labelled-product peak sits, where free radionuclide sits, what the failure-mode flags look like.
Probe + energy
High-energy scintillator; 511 keV annihilation line
Column + mobile phase
Reversed-phase C18; isocratic 5–10 % acetonitrile / aqueous
Expected chromatogram
[18F]FDG retention ~5–7 min; free [18F]⁻ near void; partially hydrolysed [18F]FDM if column degraded
Release threshold
%RCP ≥ 95 % per Eur.Ph. 1325 / USP <823>
Failure-mode flags: Multiple late-eluting peaks indicate column or solvent degradation; free [18F]⁻ above the void threshold indicates labelling-yield drop or hydrolysis during transport
Probe + energy
High-energy scintillator; 511 keV
Column + mobile phase
Anion-exchange column; phosphate / acetate buffer eluent
Expected chromatogram
[18F]NaF as sharp retained peak; no organic impurities expected from inorganic chemistry
Release threshold
%RCP ≥ 95 % per Eur.Ph. 2100
Failure-mode flags: Drift of the retention time indicates buffer pH drift; peak tailing indicates column degradation — schedule column swap
Probe + energy
High-energy scintillator; 511 keV annihilation; complementary 1077 keV pair line
Column + mobile phase
Reversed-phase C18 / C8; TFA / acetonitrile gradient
Expected chromatogram
Labelled peptide eluting at the cold-peptide UV retention time; free Ga-68 / Ga-68-colloid near the void
Release threshold
%RCP ≥ 95 % per Eur.Ph. monograph / site SOP
Failure-mode flags: Ga-68 free at void > 5 % indicates labelling under-reaction (low pH, low temperature, short reaction time); colloid above threshold indicates pH overshoot — adjust labelling SOP
Probe + energy
Medium-energy scintillator; 113 / 208 keV doublet
Column + mobile phase
Reversed-phase C18; TFA / acetonitrile gradient
Expected chromatogram
Labelled peptide eluting at the cold-peptide UV retention time; free Lu-177 / Lu-177-EDTMP near the void; degradation peaks beyond the labelled product peak
Release threshold
%RCP ≥ 95 % (NETTER / VISION protocols target ≥ 99 %)
Failure-mode flags: Free Lu-177 above void threshold indicates incomplete chelation — check DOTA-peptide stoichiometry and reaction temperature / time; late-eluting degradation peaks indicate radiolysis — review ascorbate / gentisate stabiliser concentration
Probe + energy
Low-energy scintillator; 140 keV
Column + mobile phase
Per kit-monograph reversed-phase or ion-exchange
Expected chromatogram
Tc-99m-kit labelled peak; free Tc-99m-pertechnetate near the void; reduced-hydrolysed Tc-99m as colloid at the column-front
Release threshold
%RCP ≥ 95 % per Eur.Ph. kit monograph
Failure-mode flags: Reduced-hydrolysed Tc-99m above threshold indicates stannous-reductant excess — review kit-reconstitution SOP and shelf-life
Probe + energy
High-energy scintillator; 511 keV annihilation + 1346 keV gamma
Column + mobile phase
Per IIP method development
Expected chromatogram
Labelled compound at the cold-reference retention time; free Cu-64 chelate near the void; oxidised by-products beyond the labelled peak
Release threshold
Per investigator-protocol acceptance criteria
Failure-mode flags: Investigator-initiated work uses radio-HPLC for method-development AND release. Maintain protocol-locked method version per study.
Per-isotope thresholds carried in the QC software method library; the operator does not enter the threshold on the release screen. Site IQ / OQ / PQ verifies the latest Eur.Ph. / USP <823> values and locks the method version.