High-performance liquid chromatographic method for measuring total plasma homocysteine levels

We have modified a high-performance liquid chromatographic (HPLC) procedure based on SBD-F (ammonium-7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate) pre-column derivatization to obtain an assay that is useful for routine clinical total plasma homocysteine (tHcy) analysis. The introduction of easily handled sodium borohydride instead of the traditional tri-n-butylphosphine in dimethylformamide as a reductant and a 14-min run-time using basic isocratic HPLC equipment are the more notable advantages. The addition of mercaptopropionylglycine as an internal standard contributed to improvements in the reproducibility of the assay, yielding within- and between-run precisions of 1.9 and 4% (C.V.), respectively. Reference values for fasting tHcy were 7.65 +/- 2.3 and 8.9 +/- 2.4 mu mol/l, while post-methionine load gave tHcy levels of 19.9 +/- 5.5 and 26.8 +/- 5.5 mu mol/l, for women and men, respectively (n = 40). (C) 1998 Elsevier Science B.V. All rights reserved.