QUANTITATIVE MATRIX-ASSISTED PLASMA DESORPTION MASS-SPECTROMETRY

The development of optimized sample preparation methods accompanies the history of successful applications of Cf-252-PDMS. Studying the pharmacokinetics of the antineoplastic agent etoposide serum samples from cancer patients were labelled with the homologeous compound teniposide as internal standard for the quantitative PDMS analysis. Sample purification by chloroform extraction and by thin layer chromatography turned out to be insufficient to guarantee a satisfying final PDMS result. Embedding the purified sample into a matrix of suitable substances on the target reduced the negative influence of impurities, raised the signal-to-noise ratio of molecular ions and improved the reproducibility of calibration. This preparation method was again successfully employed for the quantitative analysis of the cytostatic drug doxorubicin. The application of a different matrix optimized for the preparation of this anthracycline and its homologeous compound daunorubicin, improved the sensitivity, linearity and detection limit.