Application of a UHPLC MS/MS-based multianalyte approach for screening and validated quantification of drugs in human blood plasma often requested in the context of brain death diagnosis.

BACKGROUND

A multianalyte procedure (MAP) for the screening and quantification of drugs of different classes using ultra-high-performance liquid chromatography with tandem-mass spectrometric detection (UHPLC-MS/MS) was established. The aim was to elucidate whether this general approach could be transferred to the determination of drugs relevant for brain death diagnosis (BDD). This part of the MAP should cover alfentanil, etomidate, fentanyl, ketamine, morphine, piritramide, and sufentanil as an addition to the established gas chromatographic-mass spectrometric approach for the determination of propofol, barbiturates, and some benzodiazepines.

METHODS

This UHPLC-MS/MS approach based on liquid-liquid extraction was validated with respect to selectivity, recovery, matrix effects, process efficiency, ion suppression/enhancement, accuracy and precision, stabilities, and limits of quantification.

RESULTS

The approach was selective for the tested analytes. Accurate and precise quantification was achieved for all analytes with the exception of alfentanil and morphine. Validation data for fentanyl, piritramide, and sufentanil were acceptable, but the lowest calibrator concentration had to be set higher than half of the lower therapeutic range as recommended for BDD.

CONCLUSIONS

Only etomidate and ketamine fulfill both validation and BDD criteria. Nevertheless, the MAP allowed the simultaneous screening and quantification of >90 other central nervous system-suppressing drugs with the same extract in the same run. For the screening and accurate and precise quantification of low concentrations of alfentanil, fentanyl, morphine, piritramide, and sufentanil, methods with alternative sample preparation and analysis techniques must be developed.