A simple reversed-phase HPLC method for the estimation of dimethylarginines and homocysteine in plasma and serum.

Elevated concentrations of asymmetric dimethylarginine, symmetric dimethylarginine
and homocysteine are considered as common risk factors for cardiovascular
diseases. A simple reversed-phase high-performance liquid chromatography method
has been developed to simultaneously detect these biomarkers in plasma and serum.
Straightforward sample preparation involves direct derivatization of deproteinized
serum/plasma with phenyl isothiocyanate. Dimethylarginines and homocysteine are
resolved using a 250 × 4.6 mm I.D, C18 column and a linear gradient of sodium
acetate buffer/acetonitrile. Calibration curves of peak area verses concentration are
linear with correlation coefficients near unity. The intraday and interday precisions
measured by coefficient of variation of peak areas were 1.34–9.7, 2.7–6.7 and 0.3–
7.1 for asymmetric dimethylarginine, symmetric dimethylarginine and homocysteine,
respectively. The recoveries of asymmetric dimethylarginine, symmetric dimethylarginine
and homocysteine are above 86%.Minimal sample preparation, good recoveries
and fast run time makes this method suitable for the analysis of plasma and
serum.