UPLC-MS/MS determination in blood of a mixed-drug fatal intoxication: a case report

Trends in forensic toxicology show the introduction of rapid analytical methods for the simultaneous quantitative analysis of drugs. The authors present a fatal case involving a 32-year-old male, found dead in bed by his mother, with several blue, white and orange pills next to the body. Empty tablets were found in the trash bin and a suicide note was on the desk. He was diagnosed with bipolar disorder and had been under psychiatric treatment, having repeatedly demonstrated intent to commit suicide. A rapid method was developed to determine 55 different medicines and 32 benzodiazepines in blood by ultra-performance liquid chromatography (UPLC) coupled with tandem mass spectrometry (MS/MS) with electrospray ionization source in positive and negative ion mode. Chromatographic analysis was preceded by an optimized solid-phase extraction procedure using Oasis(®) HLB (3 cc, 60 mg) extraction columns. The extracted analytes were separated by UPLC (Waters) with a reversed-phase Acquity UPLC(®) HSS T3 (2.1×100 mm id, 1.8 μm) column with acetonitrile and 0.1% formic acid in water as mobile phase, at 0.5 mL/min flow rate and a chromatographic run-time of 8 min. Analytes detection was achieved with a triple-quadrupole mass spectrometer in positive and negative electrospray ionization mode with multiple reaction monitoring (MRM). Two MRM transitions were monitored for each target-compound and one for each deuterated internal standards. Toxicological results showed high blood concentrations of antipsychotics (haloperidol, olanzapine and quetiapine), antidepressants (fluoxetine and paroxetine) and anxiolytics (bromazepam and lorazepam). Risperidone and other benzodiazepines were also present in therapeutic concentrations. Neither alcohol nor illicit drugs were present in the analyzed samples. The UPLC-MS-MS method showed to be appropriate for screening, identification and quantitation of antipsychotics, antidepressants, anxiolytics and antiepileptic drugs in blood after intake of therapeutic as well as toxic doses. The autopsy and toxicological results led the pathologist to rule that death was due to a mixed-drug intoxication. The manner of death was determined to be suicide.