QUANTITATIVE MATRIX-ASSISTED PLASMA DESORPTION MASS-SPECTROMETRY

The development of optimized sample preparation methods accompanies th e history of successful applications of Cf-252-PDMS. Studying the phar macokinetics 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 purif ication by chloroform extraction and by thin layer chromatography turn ed 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 s ignal-to-noise ratio of molecular ions and improved the reproducibilit y of calibration. This preparation method was again successfully emplo yed 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, improve d the sensitivity, linearity and detection limit.