title: Determination of N,N',N"-triethylenthiophosphoramide in biological samples using capillary gas chromatography.
abstract: A sensitive assay for the determination of N,N',N"-triethylenthiophosphoramide (thioTEPA) in microvolumes of human plasma and urine has been developed. ThioTEPA was analysed using gas chromatography with selective nitrogen-phosphorus detection, after extraction with ethyl acetate from the biological matrix. Diphenylamine is the internal standard. The limit of quantitation was 0.1 ng/ml, using only 100 microl of sample; recoveries ranged between 85 and 100% and both accuracy and precision were less than 10%. Using a flame ionisation nitrogen-phosphorus detector, the assay was not linear over the concentration range of 2-1000 ng/ml for plasma and 10-1000 ng/ml for urine. Linearity was accomplished in the range of 1-1000 ng/ml for plasma and urine when a thermionic nitrogen/phosphorous detector was used. The stability of thioTEPA in plasma proved to be satisfactory over a period of 3 months, when kept at -20 degrees C, whereas it was stable in urine for at least 1 month at -80 degrees C. ThioTEPA plasma concentrations of two patients treated with thioTEPA are presented demonstrating the applicability of the assay.
authors.affiliation: University of Utrecht, Department of Pharmaceutical Analysis, The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: van Maanen
authors.forename: R D
authors.initials: RD
authors.lastname: van Ooijen
authors.forename: J H
authors.initials: JH
authors.lastname: Beijnen
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000032:analysis* / Q000097:blood / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013852:Thiotepa / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D018906:Antineoplastic Agents, Alkylating; D013852:Thiotepa