Assessing the Sensitivity and Efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) for High-Concentration Cadmium Detection in Cocoa Powder
Abstract
:Highlights
- The LIBS technique was successfully applied for the first time to quantify cadmium in commercial cocoa powder across concentrations ranging from 70 ppm to 5000 ppm.
- A mechanical mixing and pelletization protocol for sample preparation, combined with a background correction algorithm, significantly improved the accuracy and robustness of LIBS for cadmium detection in complex cocoa matrices.
- LIBS demonstrates its potential as a rapid, field-deployable method for food safety monitoring and industrial contamination assessments.
- The methodology validates its applicability in high-contamination scenarios and expands the use of LIBS to other plant-based matrices and environmental monitoring.
Abstract
1. Introduction
2. Experimental
2.1. Sample Preparation
2.2. Experimental Setup
3. Results
3.1. Spectral Treatment
Base Correction Algorithm
3.2. LIBS Analysis
3.2.1. Plasma Characterization
3.2.2. Calibration Curve and Detection Limits
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Element | Ionization State | Wavelength (nm) | |||||
---|---|---|---|---|---|---|---|
Cd | I | 340.36 | 7.07 × 107 | 3.73 | 7.36 | 0 | 1 |
Cd | I | 361.05 | 1.30 × 108 | 3.94 | 7.38 | 2 | 3 |
Species | Wavelength (Å) | |||||
---|---|---|---|---|---|---|
Mg I | 2776.47 | 1.32 | 2.712 | 7.175 | 3 | 5 |
Mg I | 2778.45 | 1.82 | 2.709 | 7.170 | 1 | 3 |
Mg I | 2779.65 | 1.36 | 2.712 | 7.170 | 3 | 3 |
Mg I | 2781.00 | 5.43 | 2.717 | 7.173 | 5 | 3 |
Mg I | 2782.78 | 2.14 | 2.717 | 7.170 | 5 | 3 |
Mg I | 2852.14 | 4.91 | 0.000 | 4.345 | 1 | 3 |
Mg I | 5167.09 | 1.13 | 2.709 | 5.107 | 1 | 3 |
Mg I | 5172.59 | 3.37 | 2.712 | 5.108 | 3 | 3 |
Mg I | 5183.53 | 5.61 | 2.717 | 5.108 | 5 | 3 |
Mg II | 2790.78 | 4.01 | 4.422 | 8.864 | 2 | 4 |
Mg II | 2795.23 | 2.60 | 0.000 | 4.434 | 2 | 4 |
Mg II | 2798.25 | 4.79 | 4.434 | 8.863 | 4 | 6 |
Mg II | 2802.50 | 2.57 | 0.000 | 4.422 | 2 | 2 |
Test Samples Mixed-in Concentration (μg/g) | Calculated Concentration (μg/g) | |
---|---|---|
Cadmium Lines | ||
361.05 nm | 340.43 nm | |
300 | 314 ± 25 | 335 ± 26 |
700 | 728 ± 58 | 668 ± 53 |
800 | 728 ± 55 | 780 ± 62 |
2000 | 2019 ± 161 | 1990 ± 159 |
3000 | 2720 ± 217 | 3018 ± 241 |
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Molina M., J.; Pincay, R.; Santos, V.; González, J.L.; Trujillo Guerrero, M.F.; Díaz Pace, D.; Costa-Vera, C. Assessing the Sensitivity and Efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) for High-Concentration Cadmium Detection in Cocoa Powder. Sensors 2025, 25, 2434. https://doi.org/10.3390/s25082434
Molina M. J, Pincay R, Santos V, González JL, Trujillo Guerrero MF, Díaz Pace D, Costa-Vera C. Assessing the Sensitivity and Efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) for High-Concentration Cadmium Detection in Cocoa Powder. Sensors. 2025; 25(8):2434. https://doi.org/10.3390/s25082434
Chicago/Turabian StyleMolina M., Juan, Raquel Pincay, Víctor Santos, José Luis González, María Fernanda Trujillo Guerrero, Diego Díaz Pace, and César Costa-Vera. 2025. "Assessing the Sensitivity and Efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) for High-Concentration Cadmium Detection in Cocoa Powder" Sensors 25, no. 8: 2434. https://doi.org/10.3390/s25082434
APA StyleMolina M., J., Pincay, R., Santos, V., González, J. L., Trujillo Guerrero, M. F., Díaz Pace, D., & Costa-Vera, C. (2025). Assessing the Sensitivity and Efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) for High-Concentration Cadmium Detection in Cocoa Powder. Sensors, 25(8), 2434. https://doi.org/10.3390/s25082434