Comparison of Chromatographic and Electrochemical Methods for Detecting and Quantifying Sunscreen Agents and Their Degradation Products in Water Matrices

At a Glance

Metadata	Details
Publication Date	2025-05-14
Journal	Applied Sciences
Authors	Laysa Renata Duarte Brito Sabino, Mayra Kerolly Sales Monteiro, Letícia Gracyelle Alexandre Costa, Elisama Vieira dos Santos, Carlos A. Martínez‐Huitle
Institutions	National Agency of Petroleum, Natural Gas and Biofuels, Universidade Federal do Rio Grande do Norte
Citations	1
Analysis	Full AI Review Included

Technical Documentation & Analysis: MPCVD Diamond for Advanced Electrochemistry

Reference: Sabino et al. (2025). Comparison of Chromatographic and Electrochemical Methods for Detecting and Quantifying Sunscreen Agents and Their Degradation Products in Water Matrices. Appl. Sci. 15, 5504.

Executive Summary

This research validates the superior performance of electroanalytical techniques, specifically utilizing Boron-Doped Diamond (BDD) anodes, for the detection and degradation of recalcitrant organic pollutants like Octocrylene (OC) in complex water matrices.

Superior Sensitivity: Electroanalysis (DPV using GCS) achieved significantly lower Limits of Detection (LOD) and Quantification (LOQ) for OC compared to High Performance Liquid Chromatography (HPLC).
BDD Efficacy: Boron-Doped Diamond (BDD) electrodes were confirmed as highly effective anodes for the electrochemical degradation of OC via Advanced Oxidation Processes (AOPs).
Mechanism Confirmation: OC removal is driven by the electrogeneration of powerful oxidizing species, primarily hydroxyl radicals (•OH) and active chlorine species, at the BDD surface.
Performance Scaling: Degradation efficiency was directly enhanced by increasing the applied current density (from 5 to 10 mA cm^-2), confirming the material’s suitability for high-power water treatment.
Reliable Alternative: The combined GCS sensing and BDD treatment approach offers a reliable, cost-effective, and extraction-free alternative to traditional chromatographic methods for environmental monitoring.
6CCVD Relevance: The study directly utilizes high-performance carbonaceous materials (GCS) and BDD, aligning perfectly with 6CCVD’s core manufacturing expertise in MPCVD diamond substrates for electrochemistry.

Technical Specifications

The following hard data points were extracted from the study, comparing the performance metrics of the two analytical techniques and the BDD treatment parameters.

Parameter	Value	Unit	Context
LOD (Electroanalysis, DPV)	0.11 ± 0.01	mg L^-1	Superior sensitivity for OC detection
LOQ (Electroanalysis, DPV)	0.86 ± 0.04	mg L^-1	Quantification limit
LOD (HPLC)	0.35 ± 0.02	mg L^-1	Comparative method
LOQ (HPLC)	2.86 ± 0.12	mg L^-1	Comparative method
BDD Anode Active Area	69.4 ± 0.5	cm²	Used for electrochemical treatment
Applied Current Density (J)	5 and 10	mA cm^-2	Galvanostatic OC degradation
Treatment Duration	180	min	Total duration for degradation experiments
Electrolyte pH	6.0	-	Britton-Robinson (BR) buffer
Cathodic Peak Potential (OC)	-1.13	V	vs Ag/AgCl (3M KCl)
Linear Range (DPV)	0.09 to 1.08	mg L^-1	OC concentration range

Key Methodologies

The experimental protocol focused on Differential Pulse Voltammetry (DPV) for sensing and electrochemical flow cell treatment using BDD.

Sensing Setup: A three-electrode system was used, featuring a Glassy Carbon Sensor (GCS) working electrode, an Ag/AgCl (3M KCl) reference electrode, and a Platinum counter electrode.
Working Electrode Preparation: The GCS working electrode (exposed geometric area of 3.14 ± 0.10 mm²) was polished before and after each measurement to ensure surface renewal and selective detection.
Electrolyte Conditions: Electroanalysis was performed using 10 mL of Britton-Robinson (BR) buffer solution (pH 6.0).
Voltammetry Parameters (DPV): Key parameters included a step potential of +0.005 V, modulation amplitude of +0.1 V, and an equilibrium time of 10 s.
Electrochemical Treatment Cell: An electrochemical flow cell was constructed using a Stainless Steel (SS) plate as the cathode and a Boron-Doped Diamond (BDD) circular plate as the anode.
BDD Anode Specifications: The BDD anode had an active surface area of 69.4 ± 0.5 cm² and was sourced from Metakem GmbH.
Treatment Conditions: Current densities of 5 and 10 mA cm^-2 were applied galvanostatically for 180 minutes to circulate 2 L of OC-contaminated water matrices (swimming pool water and 0.002 M Cl^- solutions).

6CCVD Solutions & Capabilities

This research demonstrates the critical role of high-performance diamond electrodes in both environmental sensing and advanced water treatment. 6CCVD is uniquely positioned to supply the necessary Boron-Doped Diamond (BDD) and carbonaceous materials to replicate, scale, and advance this research.

Applicable Materials

The core success of the electrochemical degradation relied on the high overpotential and stability of the BDD anode.

Boron-Doped Diamond (BDD): 6CCVD offers heavily doped, high-quality BDD films grown via MPCVD. These materials are essential for generating the highly reactive hydroxyl radicals (•OH) required for efficient Advanced Oxidation Processes (AOPs) like the OC degradation demonstrated here.
- Recommendation: Heavy Boron Doped PCD/BDD Wafers (up to 125mm diameter) for large-scale flow cell prototypes or BDD Substrates (up to 10mm thick) for high-power applications.
Polycrystalline Diamond (PCD) / Single Crystal Diamond (SCD): While the sensing utilized Glassy Carbon (GCS), diamond electrodes offer superior stability, wider potential windows, and lower background current.
- Recommendation: Electrochemical Grade PCD or SCD films for next-generation, highly sensitive, solid-state electrochemical sensors, replacing GCS for enhanced robustness and selectivity.

Customization Potential

6CCVD’s in-house manufacturing capabilities directly address the specific engineering requirements of advanced electrochemical systems.

Research Requirement	6CCVD Customization Capability	Benefit to Client
Electrode Dimensions	Custom plates/wafers up to 125mm (PCD/BDD).	Enables immediate scale-up from lab-scale (69.4 cm² BDD) to industrial prototypes.
BDD Thickness	SCD/PCD/BDD films from 0.1 µm up to 500 µm. Substrates up to 10mm.	Allows optimization of electrode lifetime and current density handling for high-throughput AOPs.
Surface Finish	Polishing services: Ra < 1nm (SCD), Ra < 5nm (PCD/BDD).	Critical for minimizing fouling and maximizing active surface area in sensing applications.
Electrical Contact	Internal metalization capabilities (Au, Pt, Ti, W, Cu).	Ensures robust, low-resistance electrical contacts for high-current density BDD anodes, improving system efficiency.

Engineering Support

The study highlights the necessity of controlling current density (5 vs. 10 mA cm^-2) to prevent the formation of toxic byproducts (chlorate/perchlorate).

6CCVD’s in-house PhD team specializes in the material science of diamond electrochemistry. We provide consultation on:

Doping Optimization: Tailoring boron concentration to maximize hydroxyl radical generation while maintaining selectivity.
Electrode Design: Assisting engineers in selecting the optimal diamond material (PCD vs. SCD vs. BDD) and geometry for specific Electrochemical Water Treatment and Environmental Sensing applications.
Surface Functionalization: Advising on pre-treatment and metalization strategies to enhance electrode performance and longevity in corrosive or high-current environments.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Comparing electroanalysis and chromatography, this study highlights that electroanalysis, specifically using a glassy carbon sensor (GCS), is the most appropriate choice for quantifying recalcitrant organic compounds. Octocrylene (OC), an organic compound commonly found in sunscreens, is of particular concern in swimming pool water monitoring, as its presence above legal limits poses health risks. OC quantification was performed using both high performance liquid chromatography (HPLC) and electroanalysis in sunscreen formulations and water matrices. The limits of detection (LODs) and quantification (LOQ) for OC were approximately 0.11 ± 0.01 mg L−1 and 0.86 ± 0.04 mg L−1 by electroanalysis, and 0.35 ± 0.02 mg L−1 and 2.86 ± 0.12 mg L−1 by HPLC. Electroanalysis successfully quantified OC in real sunscreen samples, and the results were comparable to those obtained by HPLC. The matrices tested—swimming pool water and distilled water (containing 0.002 M Cl−) contaminated with 0.4 ± 0.2 g L−1 of sunscreen (based on a maximum concentration in sunscreen and cosmetic formulations of 10%)—showed OC concentrations below 10% in the formulation, with no significant differences observed between the two techniques. GCS was further utilized to monitor OC degradation via anodic oxidation at current densities of 5 and 10 mA cm−2, using a boron-doped diamond (BDD) anode. The combined approach demonstrated high efficacy in both detecting and eliminating OC from various water matrices, making it a reliable and efficient alternative for environmental and water quality monitoring.

Tech Support

Original Source

DOI: https://doi.org/10.3390/app15105504

References

2014 - Contact and photocontact allergy to octocrylene: A review [Crossref]
2017 - Degradation of octocrylene using combined ozonation and electrolysis process: Optimization by response surface methodology [Crossref]
2021 - Benzophenone accumulates over time from the degradation of Octocrylene in commercial sunscreen products [Crossref]
2020 - Pharmaceuticals as emerging contaminants in the aquatic environment of Latin America: A review [Crossref]
2011 - Safety Evaluation of sunscreen formulations containing titanium dioxide and zinc oxide nanoparticles in UV-B sunburned skin: An in vitro and in vivo study [Crossref]
2011 - Electrochemical behavior and voltammetric determination of paracetamol on nafion/TiO2-graphene modified glassy carbon electrode [Crossref]