Determination of Heparin in Plasma by HPLC Coupled with Resonance Light Scattering Detection

High performance liquid chromatography coupled with resonance light scattering detection was developed for separation and determination of heparin in plasma. A good chromatographic separation was achieved using an aminex HPX-87H column (300 mm × 7.8 mm, 9 μm) and a mobile phase of 5.0 mmol L^?1 H₂SO₄ at the flow rate of 0.5 mL min^?1. The enhanced resonance light scattering signals were derived from a large aggregate formation between heparin and cetyltrimethylammonium bromide used as the molecular recognition probe. The parameters of the post-column reaction (pH, concentration and flow rate of the reagent, length of the reaction coil, and temperature) were optimized. The limit of detection for heparin in plasma was 0.2 mg L^?1. The method has been applied to the determination of heparin in dialysis patient plasmas.