Internal Standard for Paracetamol Assay
Posted: Tue Jan 08, 2008 12:09 am
Hi everyone,
I have been developing an assay for paracetamol and it's metabolites (paracetamol sulphate and paracetamol glucuronide) and the method I have developed was based ona literature method (Journal of Pharmaceutical and Biomedical Analysis, 34 (2004) 585-593). The method uses a mobile phase of 0.1M KH2PO4, 1.5% isopropanol, 0.,1% THF - I recognize that this is an unusual mobile phase but it works really well for this separation. The flow rate is 0.8mL/min and the column is a 4.6 x 250mm c18 column.
The problem I am having is finding a suitable internal standard. The paracetamol is the last of the analytes to elute (24.5min) and I would be looking for an internal standard likely to elute after this. If anyone has any suggestions I would love to hear them!
Thanks.
Merrin
I have been developing an assay for paracetamol and it's metabolites (paracetamol sulphate and paracetamol glucuronide) and the method I have developed was based ona literature method (Journal of Pharmaceutical and Biomedical Analysis, 34 (2004) 585-593). The method uses a mobile phase of 0.1M KH2PO4, 1.5% isopropanol, 0.,1% THF - I recognize that this is an unusual mobile phase but it works really well for this separation. The flow rate is 0.8mL/min and the column is a 4.6 x 250mm c18 column.
The problem I am having is finding a suitable internal standard. The paracetamol is the last of the analytes to elute (24.5min) and I would be looking for an internal standard likely to elute after this. If anyone has any suggestions I would love to hear them!
Thanks.
Merrin