ABSTRACT
Drugs deposited in human teeth are well preserved; the spectrum of toxicological investigations may therefore be supplemented by an analysis method for drugs in teeth. A liquid chromatography-electrospray ionization tandem mass spectrometry assay for the detection and quantification of basic drugs of abuse in bovine dentin samples was developed and validated. The drugs and metabolites amphetamine, methamphetamine, methylenedioxymethylamphetamine, methylenedioxyethylamphetamine, codeine, morphine, cocaine and benzoylecgonine were extracted from 50 mg ground dentin powder by ultrasonication for 60 min in methanol 3 times. The extracts were analyzed on a triple-quadrupole mass-spectrometer in multiple reaction monitoring mode. The method was validated and proved to be accurate, precise, selective, specific and stable with good linearity within the calibration range and a lower limit of quantification of 10 to 20 pg/mg. To artificially load bovine dentin samples with drugs, the natural process of de- and remineralization in the oral cavity was mimicked by a pH-cycling experiment. The artificially drug-loaded dentin samples showed drug concentrations of 20 to 80 pg/mg. The method can be applied in further in vitro experiments as well as in post-mortem cases, especially where limited sample tissue is available.
Subject(s)
Dentin/chemistry , Illicit Drugs/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Substance Abuse Detection/methods , Animals , Cattle , Chromatography, Liquid/methods , Humans , Limit of Detection , Tandem Mass Spectrometry/methodsABSTRACT
The differentiation of intoxication courses is one of the most difficult challenges for forensic pathologists and toxicologists. The case of a 52-year-old female inpatient of a psychiatric clinic with multiple medications who died from doxepin intoxication is reported. Concentrations of doxepin metabolites and isomers, pharmacokinetic modelling and genotyping of the doxepin-metabolizing cytochrome P450 (CYP) enzymes led to the following conclusion: the lethal doxepin concentration of 2100 ng/mL was more likely to have been reached due to drug interactions and genetic peculiarities leading to a reduction of the metabolic capacity and not by an acute (suicidal) overdose.
