Development and optimization of a derivatization protocol for phenethylamine compounds using FITC-CE-LIF method

In the framework of the development of an innovative microfluidic system based on capillary electrophoresis separation, we optimized a fluorescein isothiocyanate (FITC) derivatization protocol for Laser Induced Fluorescence (LIF) detection. The microfluidic device will present a high sensitivity thanks to the fluorescence detection and an innovative hydrodynamic injection approach.
To highlight the analytical performances of this microfluidic system, we will use synthetic cathinones (and some derivatives) as targeted compounds. They present a panel of closely related structures and isobaric compounds. In addition to analytical challenges, this category of drugs is a current topic regarding to public health. Indeed synthetic cathinones were described as the second most frequently seized group of new psychoactive substances in EU in 2016. Moreover some of them are currently sell on internet as bath salts without any legislation. In this context, fast, easy and reliable analytical tools are required to track and quantify these compounds.
In the present study, we initiated the optimization of the derivatization of model compounds (phenethylamine family) using FITC. The panel of model analytes includes primary and secondary amino groups to be representative of future real samples. Design of experiments strategy was used to optimize the derivatization protocol in order to reach an easy sample preparation and to maximize the derivatization efficiency.
Finally, the CE developed method will be transferred to the microfluidic system. Then separation performances comparison of traditional CE-LIF vs µCE-LIF will allow to highlight the advantages of microfluidics such as the lower amount of sample required, the gain in time and money, the significant decrease of solvent and its compact size.