A robust liquid chromatography tandem mass spectrometry method for total plasma homocysteine determination in clinical practice

Background: Total plasma homocysteine has emerged as an independent risk factor for vascular disease. To meet increasing requests by clinicians for this homocysteine determination, a rapid assay for a routine use has been developed. Methods: A robust, stable, isotope-dilution liquid chromatography tandem mass spectrometry (LC/MS/MS) method is described, including all the practical details and analytical performance results. Results: The method allows homocysteine quantitation over a linear working range up to 100 mmol/L, with the limit of quantification estimated at a low value of 0.09 mmol/L. Total analytical imprecision is less than 4%. Accuracy was assessed by measuring the homocysteine concentration in a serum Standard Reference Material. Conclusions: The method was demonstrated to be quick, reliable and cheap after 1 year of use on a time-shared instrument in our hospital unit.