Examination of Pretreatment Conditions (2) Dependency on Quantity of Eluent
In the column switching method, using acetaminophen (a hydrophilic drug), we investigated the influence of switching time of the analysis. The flow rate in the pretreatment column was fixed (0.5mL/min). The switching time was changed from 5 to 20 minutes. Since drugs are absorbed to MSpak PK-2A with the hydrophobic interaction, the adsorption of Hydrophilic drugs to PK-2A is weak. Please be careful of the timing which changes the valve.
Please refer to System diagram.
Sample : 2.5ppm Acetaminophen, 100micro-L
Pretreatment Column : Shodex MSpak PK-2A (2.0mmID*10mm) Eluent : 10mM CH3COONH4(pH7.0) Flow rate : 0.5mL/min Column temp. : Room temp. Analysis Column : Shodex MSpak GF-4A (4.6mmID*10mm) x 2 Eluent : 10mM CH3COONH4(pH7.0)/CH3CN=85/15 Flow rate : 0.3mL/min Detector : UV(254nm) Column temp. : Room temp.