Table 1.

Influence of reducing washing agent volume on purification performance of SepPak C18 light (in-tandem alignment connected back-to-back).

Treatment (Wash & Rinse)	Activity Retention (%LA)	Activity Retention (%LA) Post-Wash	Recovery Efficiency (%RA)	RCP (%)
1 mL PBS (n = 9)	99.7 ± 0.2	85.8 ± 6.9	60.7 ± 12.7	100
0.4 mL PBS (n = 6)	99.8 ± 0.1	94.9 ± 6.2	83.5 ± 7.6	100

The SepPak C18 tandem setting was pre-conditioned with 10 mL of EtOH and 10 mL of H₂O. Product activity was recovered from the cartridge via slow elution with 1 mL of 5% v/v EtOH (aqua) solution. Before purification, the RCP was determined via HPLC analysis of a crude reaction solution of ≥95%. %LA = percentage of the total loaded radioactivity from the starting radioactivity, with %LA measured (MBq) on the cartridges after the loading step pre- and post-wash. %RA = percentage of the total recovered radioactivity from the starting radioactivity with RA measured (MBq) after the activity elution (recovery) step.