Study of the electro-oxidation of a recreational drug GHB (gamma hydroxybutyric acid) on a platinum catalyst-type electrode through chronoamperometry and spectro-electrochemistry

Abstract

Abstract.The electro-oxidation of gamma-hydroxybutyric acid (GHB) on a polycrystalline platinum electrode in acidic medium has been studied using chronoamperometry. The study has been performed in a wide interval of potentials and at different concentrations.It was found that at longer times the density currents reached stationary values at more anodic potentials, whereas it is zero at lower potentials. These characteristics in the j-t curves suggest a different mechanism for the electro-oxidation of GHB, potential dependent, with a catalytic process at high potentials and an adsorption process controlled by mass transport at low potential.The change in the stationary current obtained at +0.9 V with variable GHB concentrations also suggests an oxidation mechanism catalysed by the platinum surface with platinum hydroxides acting as reaction intermediates to make the final oxidation product for GHB. The results obtained using chronoamperometry are in good agreement with those obtained using cyclic voltammetry where the alcohol group is oxidised at different potentials.In situ Surface Enhanced Raman Scattering (SERS) spectra corresponding to GHB intermediates and water adsorbed species being formed/consumed at the potentialdependent adsorption processes have been analyzed using spectro-electrochemistry. A peak at 1590 cm -1 , corresponding to the asymmetric stretching of carboxylic group in a bridge configuration, increases with the potential. This supports the hypothesis of a mechanism of formation of the succinic acid on the platinum surface as reaction product under the experimental conditions studied.2

Evolution of Pt and Ag nanoparticles composites with polyphenazines onto ITO electrodes during the oxidation of H2O2 with ascorbic acid

“…At 1153 cm -1 the C-N-C vibration of the tertiary amino group can be also observed [25]. The bands appearing in this range are attenuated by the presence of platinum as the wavelength range 350-410 cm -1 corresponding to Pt-Ox or Pt-OH vibrations [26,27]. The presence of Platinum is confirmed by EDX measurements (see figure S2 in supplementary material).…”

Interpol review of controlled substances 2016–2019

“…Gamma-Hydroxybutyric Acid (GHB) (also gamma-Butyrolactone (GBL), 1,4- Butanediol (BD), and Tetrahydrofuran (THF)): 2016 Electro-oxidation of GHB using chronoamperometry and spectroelectrochemistry [ 202 ]; effect of temperature on the electro-oxidation of GHB analyzed by cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy and SERS Spectroelectrochemistry [ 203 ]; 2017 study of endogenous GHB in a variety of drinks analyzed by GC-MS/MS [ 204 ]; method for simultaneous quantitative analysis of BHB and GHB by GC-MS [ 205 ]; real-time detection method for GHB using a iridium(III) chemosensor to produce luminescence signal that can be observed under UV illumination [ 206 ]; 2019 electrooxidation of GHB and ethanol by cyclic voltammetry and chronoamperometry [ 207 ]; detection of isomers of gamma-hydroxybutyrate using LC-ESI-MS/MS [ 208 ]; sensor for the detection of tetrahydrofuran in vapor form [ 209 ]; investigation of the formation, structure, and stability of Tetrahydrofuran [ 210 ].…”

Forensic Identification of Fentanyl and its Analogs by Electrochemical-Surface Enhanced Raman Spectroscopy (EC-SERS) for the Screening of Seized Drugs of Abuse

“…Therefore, electrochemical-surface enhanced Raman spectroscopy (EC-SERS) has become a useful spectroelectrochemical approach. In an EC-SERS methodology, the SERS substrate is prepared by electrochemical roughening and generation of nanoparticles in-situ, differing from other approaches where the electrodes are modified with nanoparticles or colloids or where electrochemistry is used for preconcentration (Robinson et al, 2012;Jiménez-Pérez et al, 2016a;Jiménez-Pérez et al, 2016b;Ameku et al, 2019).…”