Quantification of perifosine, an alkylphosphocholine anti-tumour agent, inplasma by pneumatically assisted electrospray tandem mass spectrometry coupled with high-performance liquid chromatography

An HPLC assay with tandem mass spectrometric detection in the positive-ion Turbo-Ion-Spray (TISP) mode for the fast and sensitive determination of per ifosine ((I), D-21266) in human plasma was developed, utilising the structu ral analogue, miltefosine ((II), D-18506), as internal standard. Automated solid-phase extraction of diluted plasma samples, based on 250-mu l plasma aliquots, at pH 6.5, allowed a reliable quantification of perifosine down t o 4 ng/ml. Injection of 200 mu l of plasma extracts onto a 100X3 mm normal- phase analytical column at a flow-rate of 0.5 ml/min provided retention-tim es of 2.4 and 2.1 min for perifosine (I) and the internal standard (II), re spectively. The standard curves were linear from 4 to 2000 ng/ml using weig hted linear regression analysis (1/Y-2). The inter-assay and intra-assay ac curacies for the calibration standards were within +/-0.9% and -0.2%, exhib iting precisions (C.V.) of +/-6.5 and +/-7.3%, respectively. Up to 100 unkn owns may be analysed each 24 h per analyst. (C) 1999 Elsevier Science B.V. All rights reserved.