Monitoring of the electrochemical oxidation of venlafaxine and its metabolite o-desmethylvenlafaxine using a flow cell and high-resolution mass spectrometry
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-07-10 |
| Journal | Environmental Sciences Europe |
| Authors | Melanie Voigt, Jean-Michel Dluziak, Nils Wellen, Victoria Langerbein, Martin Jaeger |
| Institutions | Hochschule Niederrhein |
| Citations | 1 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: BDD Electrodes for Advanced Oxidation Processes (EAOPs)
Section titled âTechnical Documentation & Analysis: BDD Electrodes for Advanced Oxidation Processes (EAOPs)âExecutive Summary
Section titled âExecutive SummaryâThis research validates the critical role of Boron-Doped Diamond (BDD) electrodes in Electrochemical Advanced Oxidation Processes (EAOPs) for eliminating persistent pharmaceutical micropollutants from water.
- Core Application: Successful electrochemical oxidation and degradation of venlafaxine and its metabolite (o-desmethylvenlafaxine), substances listed on the EU watchlist for water policy.
- Material Validation: Confirmed the necessity of high-quality BDD electrodes, specifically requiring a high boron doping concentration (6000 to 8000 ppm) to maximize anodic oxidation efficiency.
- Mechanism Confirmation: Mechanistic studies using radical scavengers confirmed that the indirect oxidation pathway, driven by highly reactive hydroxyl radicals (HO·) generated at the BDD surface, is the dominant degradation route.
- Optimal Conditions: Best elimination efficiency was achieved under acidic conditions (pH 3) and a relatively low potential (1.5 V), demonstrating the BDD materialâs robustness in harsh environments.
- Flow Cell Advantage: The use of a continuous flow cell setup (”PrepCell) allowed for rapid product formation monitoring and optimization of degradation kinetics, crucial for scaling up industrial wastewater treatment plants (WWTPs).
- Ecotoxicity Reduction: QSAR analysis showed that the transformation products generated via the indirect BDD oxidation mechanism generally exhibit lower ecotoxicity than the initial drug compounds.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the study, highlighting the material and operational requirements for effective EAOP implementation.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Electrode Material | Boron-Doped Diamond (BDD) | N/A | Working electrode for EAOPs |
| Boron Doping Level | 6000 to 8000 | ppm | Required concentration for high anodic activity |
| Optimal Elimination Voltage | 1.5 | V | Voltage yielding best elimination and lowest ecotoxicity |
| Maximum Voltage Tested | 3500 | mV (3.5 V) | Used for recording mass voltammograms |
| Optimal pH for Degradation | 3 | N/A | Acidic medium proved favorable for strong product formation |
| Flow Rate (Flow Cell) | 50 | ”L/min | Continuous sample flow rate |
| SCD/PCD Thickness (6CCVD Capability) | 0.1”m - 500”m | ”m | Relevant range for thin-film BDD coatings |
| Hydroxyl Radical Potential (E°) | 2.8 | V | High standard oxidation-reduction potential of HO· |
| Transformation Products Identified | 5 (Venlafaxine), 4 (o-desmethylvenlafaxine) | N/A | Observed using HPLC-HRMS |
Key Methodologies
Section titled âKey MethodologiesâThe experimental success hinges on the precise control of the BDD material and the flow cell parameters.
- BDD Electrode Selection: A high-quality BDD working electrode was chosen, featuring a heavy boron doping level (6000 to 8000 ppm) to ensure maximum generation of reactive oxygen species (ROS).
- Flow Cell Configuration: Electrochemical oxidation was performed in a continuous flow cell (”PrepCell) connected to a potentiostat, allowing for dynamic monitoring of product formation versus applied voltage.
- Electrochemical Monitoring: Mass voltammograms were recorded by scanning the potential from 0 to 3500 mV at a slow rate of 5 mV/s, enabling correlation between voltage input and transformation product formation.
- Chemical Environment Control: Experiments systematically varied the solution pH (3, 6, 9) using formic acid, sulfuric acid, or ammonia, and utilized tert-butanol as a radical scavenger to confirm the dominance of the hydroxyl radical (indirect) mechanism.
- Product Elucidation: High-resolution hybrid-orbitrap mass spectrometry (HPLC-HRMS) was used to structurally confirm nine transformation products, allowing for detailed analysis of the degradation pathways.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research confirms the critical need for high-quality, heavily doped BDD electrodes for effective EAOPs in environmental remediation. 6CCVD is uniquely positioned to supply the necessary materials and engineering support to replicate, scale, and advance this research.
| Research Requirement | 6CCVD Solution & Capability | Technical Advantage & Sales Proposition |
|---|---|---|
| High-Doping BDD Material | Heavy Boron-Doped Diamond (BDD) | 6CCVD specializes in MPCVD BDD films, guaranteeing doping levels that meet or exceed the required 6000-8000 ppm range for maximum hydroxyl radical (HO·) generation and high current efficiency, ensuring rapid mineralization of micropollutants. |
| Custom Electrode Geometry | Custom Dimensions & Laser Cutting | The study utilized a specific flow cell (”PrepCell). 6CCVD provides BDD plates/wafers up to 125mm (PCD) and offers precision laser cutting services to fabricate electrodes matching any proprietary flow cell or reactor geometry required for pilot or industrial scale-up. |
| Optimized Film Thickness | SCD/PCD/BDD Films (0.1”m - 500”m) | We supply BDD films with tightly controlled thickness, ensuring optimal conductivity, thermal management, and extended service life, critical for continuous, high-throughput wastewater treatment applications. |
| Robust Electrical Contact | Custom Metalization Services | The acidic conditions (optimal pH 3) demand robust contacts. 6CCVD offers in-house metalization (Au, Pt, Ti, W, Cu) tailored for chemical resistance and superior adhesion, guaranteeing reliable integration into electrochemical systems. |
| Surface Quality for Flow Cells | Advanced Polishing (Ra < 5nm for PCD) | Uniform surface quality is essential for predictable current density. Our polishing services ensure a smooth surface (Ra < 5nm for inch-size PCD), minimizing fouling and maximizing the active area for radical generation. |
| Engineering Support for Mechanism Optimization | In-House PhD Material Science Team | The paper highlights the complexity of favoring the indirect (HO·) pathway. 6CCVDâs experts can consult on material selection, doping profile, and surface termination to optimize BDD electrodes specifically for targeted EAOP mechanisms, accelerating R&D cycles for similar environmental projects. |
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract Background The antidepressant venlafaxine and its metabolite o -desmethylvenlafaxine are frequently found in water bodies around the world reaching several micrograms per liter. As a remedy, electrochemical advanced oxidation processes (EAOPs) such as anodic oxidation with a boron-doped diamond (BDD) electrode have proven to be a suitable means to prevent entrance in the aquatic environment. For potential application, optimization of the EAOPs can be readily achieved by variation of the conditions using a flow cell as compared to a batch-mode cell. Monitoring and characterization of the reactants provide inside into the oxidation mechanism. Results High-performance liquid chromatography and high-resolution mass spectrometry led to the observation of five transformation products of venlafaxine and to four of o -desmethylvenlafaxine. Mass voltammograms were recorded from which the impact of the oxidation conditions on the degradation and the quantity and nature of transformation products were derived. The transformation pathways were identified as well. Detailed analysis revealed that hydroxyl radicals played the major role in the electrochemical oxidation of venlafaxine and o -desmethylvenlafaxine. The prevalence of the hydroxyl radical induced degradation was further corroborated by the radical scavenger tert -butanol, causing a decrease in elimination efficiency. Both drugs were best eliminated at pH 3 and a voltage of 1.5 V, with the least ecotoxicological concern as indicated by QSAR analysis. Conclusion The study shall contribute to the advancement of EAOPs for advanced stages in wastewater purification treatment. An in silico ecotoxicity assessment using QSAR analysis showed that electrochemical oxidation is beneficial from an ecotoxicological point of view. Especially products formed via the indirect hydroxyl radical-induced mechanism showed a lower ecotoxicity than the initial compound. Graphical Abstract