Computerized mass spectrometric assay for sulindac and its metabolites in human plasma.

The development of a mass spectrometric isotope dilution assay for the sulfoxide Sulindac and its two metabolites (the corresponding sulfide and sulfone) in human plasma is described. The method involves the use of deuterium-containing analogs as internal standards. Isolates are anlyzed by repetitive-scanning direct-probe mass spectrometry. Intergration of intensities of the molecular ions of the six compounds of interest and all calculations leading to the final report (μg/ml) are carried out by automated data analysis using a computer.