Ionic liquids as signal amplifiers for the simultaneous extraction of several neurotransmitters determined by micellar electrokinetic chromatography.

Nowadays, ionic liquids (ILs) are receiving more attention in various fields of analytical chemistry. Their contribution to the enhancement of the clean-up, extraction, separation and determination of trace amounts of various biologically important compounds in distinct matrices is well documented. Moreover, their importance as "green chemistry" solvents has been pointed out. Advanced analytical methods based on the IL-assisted microextraction and electrophoretic determination of minute concentrations of neurotransmitters (NTs) in samples are presented here for the first time. In this paper, experimental data showed the usefulness of the chosen imidazolium-based ILs in solid-phase microextraction (SPME), followed by the micellar electrokinetic chromatography (MEKC) determination of three biogenic amines: dopamine, noradrenaline and adrenaline together with such amino acids as L-tyrosine and L-tryptophan. A significant increase in SPME yields, using 1-ethyl-3-methylimidazolium tetrafluoroborate as a component of the desorbent, allowing from 9 to 21 times the signal enhancement for the selected NTs, has been achieved. The elaborated IL-based SPME procedures might serve as a straightforward analytical platform for the unbiased analysis of NTs as biomarkers of various diseases where an unbalanced secretion of NTs is registered.