Development of a capillary zone electrophoresis method including a factorial design and simplex optimisation for analysis of amphetamine, amphetamine analogues, cocaine, and heroin

Electromigrative separation techniques in forensic science: combining selectivity, sensitivity, and robustness

In this review we introduce the advantages and limitations of electromigrative separation techniques in forensic toxicology. We thus present a summary of illustrative studies and our own experience in the field together with established methods from the German Federal Criminal Police Office rather than a complete survey. We focus on the analytical aspects of analytes' physicochemical characteristics (e.g. polarity, stereoisomers) and analytical challenges including matrix tolerance, separation from compounds present in large excess, sample volumes, and orthogonality. For these aspects we want to reveal the specific advantages over more traditional methods. Both detailed studies and profiling and screening studies are taken into account. Care was taken to nearly exclusively document well-validated methods outstanding for the analytical challenge discussed. Special attention was paid to aspects exclusive to electromigrative separation techniques, including the use of the mobility axis, the potential for on-site instrumentation, and the capillary format for immunoassays. The review concludes with an introductory guide to method development for different separation modes, presenting typical buffer systems as starting points for different analyte classes. The objective of this review is to provide an orientation for users in separation science considering using capillary electrophoresis in their laboratory in the future.

Distribution of methamphetamine and its metabolite amphetamine in acute and subacute ethanol-methamphetamine combination abuse model rats

The aim of this study is to investigate the distribution of methamphetamine (MA) and its metabolite amphetamine (AP) in rat models of acute and subacute MA-ethanol combination abuse. Rats were fed with 20% ethanol for 4 weeks (chronic active-drinking group), and MA was injected intraperitoneally into chronically drinking and normal rats over 5 and 14 days, respectively. Then the rats from the acute and subacute combination abuse groups were euthanized, and ethanol, MA, and AP concentrations in samples were quantified. Except for the similar ethanol concentrations among acute and subacute groups, the MA and AP levels between groups were quite different. The concentrations of MA and AP in rats' liver, lung, kidney, and brain were much higher than other tissues, regardless of combination with ethanol. Also, MA and AP levels in subacute rats groups were higher than those in acute groups, and the levels of MA and the formation of AP in rats subjected to the combination abuse with ethanol were higher than in MA-only intoxicated rats. We conclude that ethanol has no bearing on the MA and AP distribution in body fluids and tissues, yet it can increase MA levels and markedly accelerate the formation of AP in combination-abuse rats. Comparing the acute and subacute combination-abuse rats' samples, it can be deduced that various accumulated amounts of MA and AP were unaffected by ethanol, even after multi-dose injection, regardless of acute or subacute use.