Determination of perhexiline and hydroxyperhexiline in plasma by liquid chromatography-mass spectrometry.
A method for the quantitative determination of perhexiline and its main hydroxylated metabolites in human plasma, based on liquid chromatography-mass spectrometry (LC-MS), was developed. The method used protein precipitation with acetonitrile followed by dilution with water and subsequent direct injection of the extract into the LC-MS system. Hexadiline was used as internal standard and the intra-assay coefficients of variation were <or=5% for perhexiline and cis-hydroxyperhexiline over the target concentration range in patients. The lower limits of quantification were 0.005mg/l for perhexiline and 0.015mg/l for cis-hydroxyperhexiline, and the measuring ranges were from 0.05 to 3.0 and from 0.2 to 6.0mg/l, respectively. The method was compared with an established HPLC method with fluorescence detection and the correlation between the methods was close to 1 for both compounds. The predominant form of hydroxyperhexiline in 87% of the patient samples was found to be one of the diastereomeric pairs of cis-hydroxyperhexiline. In patients not forming this metabolite, trans-hydroxyperhexiline could be detected. We conclude that the present LC-MS method is suitable for use in a clinical routine laboratory.
Beck
O
O
Department of Medicine, Division of Clinical Pharmacology, Karolinska Hospital & Institute, SE-17176 Stockholm, Sweden. olof.beck@ks.se
Stephanson
N
N
Morris
R G
RG
Sallustio
B C
BC
Hjemdahl
P
P
D002317:Cardiovascular Agents / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007536:Isomerism; D013058:Mass Spectrometry / Q000379:methods*; D010480:Perhexiline / Q000031:analogs & derivatives* / Q000097:blood*; D012015:Reference Standards
D002317:Cardiovascular Agents; C493998:hydroxyperhexiline; D010480:Perhexiline