Chromatography Forum

I am trying to detect codeine by hplc and would appreciate some advice on a mobile phase. I have tried a few recommended ones and am getting nowhere

So far I have tried:

70:30 water:acetonitrile
70:30 water:acetonitrile with 0.1% formic acid
85:15 Phosphate buffer:acetonitrile pH3
50:50 methanol:0.01% ammonium carbonate

and have received no results using a 1000mg/L codeine stock sample and was expecting a large peak

I got a peak at 15 min using 80:20 methanol:0.01% ammonium carbonate but there was peak tailing.

Could anyone suggest other mobile phases I could try.

I have left my notes in uni, so cant describe the column until tomorrow other than it is a c18 and using UV detection

Thanks

Hi

Below is the purity test for Codeine and varous Codeine salts in the european pharmacopiea, might not be the best method around and I have not tried it myself, but can be a starting point.

Related substances. Liquid chromatography (2.2.29).
Test solution. Dissolve 0.100 g of the substance to be examined and 0.100 g of sodium octanesulfonate R in the mobile phase and dilute to 10.0 mL with the mobile phase.
Reference solution (a). Dissolve 5.0 mg of codeine impurity A CRS in the mobile phase and dilute to 5.0 mL with the mobile phase.
Reference solution (b). Dilute 1.0 mL of reference solution (a) to 20.0 mL with the mobile phase.
Reference solution (c). Dilute 1.0 mL of the test solution to 50.0 mL with the mobile phase. Dilute 5.0 mL of this solution to 100.0 mL with the mobile phase.
Reference solution (d). To 0.25 mL of the test solution, add 2.5 mL of reference solution (a).
Column:
— size: l = 0.25 m, Ø = 4.6 mm;
— stationary phase: end-capped octylsilyl silica gel for chromatography R (5 µm).
Mobile phase: dissolve 1.08 g of sodium octanesulfonate R in a mixture of 20 mL of glacial acetic acid R and 250 mL of acetonitrile R and dilute to 1000 mL with water R.
Flow rate: 2 mL/min.
Detection: spectrophotometer at 245 nm.
Injection: 10 µL.
Run time: 10 times the retention time of codeine