Versatile additively manufactured (3D printed) wall-jet flow cell for high performance liquid chromatography-amperometric analysis: application to the detection and quantification of new psychoactive substances (NBOMes)

Additive manufacturing (AM/3D printing) is an emerging technology of vast applicability, receiving significant interest in a plethora of industrial domains and scientific research since it allows the rapid translation of designs producedviacomputer software, into AM/3D printed objects. To date, AM/3D printed devices have been examined for their utilisation as convenient and cost-effective tools towards the detection and quantification of prevalent drugs of abuse. Herein, a novel AM/3D printed wall-jet flow cell was fabricated specifically for employment in high performance liquid chromatography-amperometric detection (HPLC-AD) of various analytes (New Psychoactive Substances). Five sensing platforms were investigated, utilising different working electrodes, namely; screen-printed graphite electrodes (SPEs), AM/3D Proto-Pasta, AM/3D Black Magic, graphite sheet and AM/3D printed nanographite (NG)/polylactic acid (PLA) towards the detection of New Psychoactive Substances. The flow cell was also optimised with respect to the cell geometry demonstrating significant benefits such as simple production and operation and the ability to tailor the platform to a variety of working electrodes. The AM/3D printed sensing platforms were characterised towards the (electro) analytical detection of fourN-benzylmethoxy-derivatives: 25F-NBOMe, 25C-NBOMe, 25B-NBOMe and 25I-NBOMe. Furthermore, the (electro) analytical performance of the flow cell was compared with the findings in our previous work comprising of a commercially available impinging jet flow cell. The SPEs and the graphite sheet were found to demonstrate superior electrochemical (analytical) sensitivity and higher reproducibility towards the quantification of the drugs in question, followed by the NG/PLA AM, Proto-Pasta and the Black Magic. The working electrodes that exhibited satisfactory (electro) analytical responses were employed for the analysis of NBOMe derivatives in three simulated blotter papers.