Sensitive stereospecific determination of acenocoumarol and phenprocoumon in plasma by high-performance liquid chromatography

We describe a normal-phase HPLC method for the stereospecific determination of R- and S-acenocoumarol and R- and S-phenprocoumon with S-warfarin as in ternal standard. The compounds were separated using a Whelk-Ol chiral stati onary phase, detected by UV at 310 nm and quantified in the internal standa rd mode. Linearity was verified for acenocoumarol in the range of 15-2000 m u g/l and for phenprocoumon from 15 to 2200 mu g/l, respectively. The detec tion limits were 5 mu g/l for all compounds. The recovery was >84% for R- a nd S-acenocoumarol and >74% for R- and S-phenprocoumon. The imprecision (C. V.) (50-1800 mu g/l) for R- and S-acenocoumarol was <4.7% within-day and (7 .8% between-day. For R- and S-phenprocoumon the respective values were <5.6 % and <5.9%. The accuracy for all compounds was 96.5-110%. (C) 2000 Elsevie r Science B.V. All rights reserved.