Procainamide in Serum

This shows one advantage of using an alkaline eluent for the analysis of procainamide in serum such as procainamide. Procainamide cannot be separated from other serum components at pH 3 or 7. However, since procainamide, which is one of a tertiary amine, dissociates a little at pH11, in consequence, it is strongly retained by the packing material of Asahipak ODP-50 4D ( a column for reversed phase chromatography ) and can be separated from other serum components.
As explained above, for the analysis of basic drugs which have tertiary amino groups, an alkaline eluent at pH11 is effective.

1) Dissolve procainamide in CH₃CN (1.0mg/mL).
2) Put 10 micro-L of the above in the centrifuge tube and blow dry it.
3) Add 1,000 micro-L of the serum and stir.
4) Add 3,000 micro-L of CH₃CN and stir.
5) Centrifuge (3,500rpm , 20min) skim and filtrate by using a 0.45 micron filter to make a sample.
6) Inject 20 micro-L of the sample.

Sample : Procainamide in serum

Column       : Shodex Asahipak ODP-50 4D (4.6mmID*150mm)
Eluent       : 25mM Phosphate buffer/CH3CN=75/25
Flow rate    : 0.6mL/min
Detector     : UV(254nm)
Column temp. : 30deg-C