RESUMEN

Paper spray tandem mass spectrometry is used to identify and quantify eight individual amphetamines in whole blood in 1.3 min. The method has been optimized and fully validated according to forensic toxicology guidelines, for the quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), and 4-fluoroamphetamine (4-FA). Additionally, a new concept of intrinsic and application-based selectivity is discussed, featuring increased confidence in the power to discriminate the amphetamines from other chemically similar compounds when applying an ambient mass spectrometric method without chromatographic separation. Accuracy was within ±15% and average precision was better than 15%, and better than 20% at the LLOQ. Detection limits between 15 and 50 ng/mL were obtained using only 12 µL of whole blood. Graphical abstract ᅟ.

Asunto(s)

Anfetamina/sangre , Estimulantes del Sistema Nervioso Central/sangre , Toxicología Forense/métodos , Espectrometría de Masas/métodos , Anfetamina/análisis , Estimulantes del Sistema Nervioso Central/análisis , Humanos , Límite de Detección , Papel , Reproducibilidad de los Resultados , Detección de Abuso de Sustancias/métodos

RESUMEN

Ionized benzophenones ([PhC(O)PhY](+*); Y = 4 - NO(2), 4 - CF(3), 4-F, 4-Br, 4-Me, 3,4-diMe, 4-OH, 4-OMe, 2-Cl, 2-Me, 2-OH, 2,6-diMe) undergo competitive dissociation upon collision-induced dissociation (CID) at 20 eV collision energy to generate benzoyl cations ([PhCO](+) and [YPhCO](+)) and phenyl radicals (Ph(*) and YPh(*)). For the para-substituted benzophenones, the natural logarithm of the abundance ratio of the benzoyl cations [ln([PhCO(+)]/[YPhCO(+)])] is found to correlate linearly with the calculated CO(+*) affinities of the phenyl radicals Ph(*) and YPh(*). A deviation from linearity is observed for the ortho-substituted isomers. This is probably due to a significant intramolecular steric interaction between the carbonyl group and the ortho substituent which prevents the formation of a stable planar system. An observed shift in the intercept relative to the origin is interpreted as the result of a systematic error in the calculated CO(+*) affinities and this effect is minimized by calculations at a higher level. The dissociation of ionized para-substituted benzophenones is associated with a relatively high effective temperature of 1816 +/- 41 K, calculated from the slope of the kinetic method plot, a value that is consistent with a covalent bond in the activated ion. In addition, Delta(DeltaS(CO(+) )), the dissociation entropy of the benzoyl cations to form CO(+*) and the aryl radical, is found to be about 4 J mol(-1) K(-1) by employing the extended version of the kinetic method.