Determination of suramin by micellar electrokinetic chromatography with direct serum injection.

A simple and reproducible micellar electrokinetic chromatography (MEKC) method has been developed for the quantitation of suramin serum levels to be used for its therapeutic drug monitoring (TDM). A running buffer solution of 20 mM sodium borate, 75 mM sodium dodecyl sulfate (SDS), and 4 M urea at pH 9.2 were employed and samples were introduced directly into the capillary. The voltage applied for sample separation was 25 kV and UV detection was at 254 nm. Linearity was proved over the range 47.6 micrograms/mL-523.6 micrograms/mL of suramin (r: 0.9996). Orange G was used as internal standard and no interferences of common drugs simultaneously administered to patients were observed. Recovery values of the intraday and interday assays were between 92.5 and 97.2%.