Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization
There is a growing interest in monitoring microplastics in the environment, corresponding to increased public concerns regarding their potential adverse effects on ecosystems. Monitoring microplastics in the environment is difficult due to the complex matrices that can prevent reliable analysis if s...
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doaj-8f380ebe350a4c548015f111313770202020-11-25T03:44:00ZengMDPI AGWater2073-44412020-08-01122445244510.3390/w12092445Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and StandardizationMohammed S. M. Al-Azzawi0Simone Kefer1Jana Weißer2Julia Reichel3Christoph Schwaller4Karl Glas5Oliver Knoop6Jörg E. Drewes7Chair of Urban Water Systems Engineering, Technical University of Munich, 85748 Garching, GermanyChair of Brewing and Beverage Technology, Technical University Munich, 85354 Freising, GermanyChair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, 85354 Freising, GermanyChair of Urban Water Systems Engineering, Technical University of Munich, 85748 Garching, GermanyChair of Urban Water Systems Engineering, Technical University of Munich, 85748 Garching, GermanyChair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, 85354 Freising, GermanyChair of Urban Water Systems Engineering, Technical University of Munich, 85748 Garching, GermanyChair of Urban Water Systems Engineering, Technical University of Munich, 85748 Garching, GermanyThere is a growing interest in monitoring microplastics in the environment, corresponding to increased public concerns regarding their potential adverse effects on ecosystems. Monitoring microplastics in the environment is difficult due to the complex matrices that can prevent reliable analysis if samples are not properly prepared first. Unfortunately, sample preparation methods are not yet standardized, and the various efforts to validate them overlook key aspects. The goal of this study was to develop a sample preparation method for wastewater samples, which removes natural organic matter without altering the properties of microplastics. Three protocols, based on KOH, H<sub>2</sub>O<sub>2</sub>, and Fenton reactions, were chosen out of ten protocols after a literature review and pre-experiments. In order to investigate the effects of these reagents on seven polymers (PS, PE, PET, PP, PA, PVC, and PLA), this study employed µFTIR, laser diffraction-based particle size analysis, as well as TD-Pyr-GC/MS. Furthermore, the study discussed issues and inconsistencies with the Fenton reactions reported in the literature in previous validation efforts. The findings of this study suggest that both H<sub>2</sub>O<sub>2</sub> and Fenton reactions are most effective in terms of organic matter removal from microplastic samples while not affecting the tested polymers, whereas KOH dissolved most PLA and PET particles.https://www.mdpi.com/2073-4441/12/9/2445microplasticswastewaterFenton reactionhydrogen peroxidedigestion methodssample preparation |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Mohammed S. M. Al-Azzawi Simone Kefer Jana Weißer Julia Reichel Christoph Schwaller Karl Glas Oliver Knoop Jörg E. Drewes |
spellingShingle |
Mohammed S. M. Al-Azzawi Simone Kefer Jana Weißer Julia Reichel Christoph Schwaller Karl Glas Oliver Knoop Jörg E. Drewes Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization Water microplastics wastewater Fenton reaction hydrogen peroxide digestion methods sample preparation |
author_facet |
Mohammed S. M. Al-Azzawi Simone Kefer Jana Weißer Julia Reichel Christoph Schwaller Karl Glas Oliver Knoop Jörg E. Drewes |
author_sort |
Mohammed S. M. Al-Azzawi |
title |
Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization |
title_short |
Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization |
title_full |
Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization |
title_fullStr |
Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization |
title_full_unstemmed |
Validation of Sample Preparation Methods for Microplastic Analysis in Wastewater Matrices—Reproducibility and Standardization |
title_sort |
validation of sample preparation methods for microplastic analysis in wastewater matrices—reproducibility and standardization |
publisher |
MDPI AG |
series |
Water |
issn |
2073-4441 |
publishDate |
2020-08-01 |
description |
There is a growing interest in monitoring microplastics in the environment, corresponding to increased public concerns regarding their potential adverse effects on ecosystems. Monitoring microplastics in the environment is difficult due to the complex matrices that can prevent reliable analysis if samples are not properly prepared first. Unfortunately, sample preparation methods are not yet standardized, and the various efforts to validate them overlook key aspects. The goal of this study was to develop a sample preparation method for wastewater samples, which removes natural organic matter without altering the properties of microplastics. Three protocols, based on KOH, H<sub>2</sub>O<sub>2</sub>, and Fenton reactions, were chosen out of ten protocols after a literature review and pre-experiments. In order to investigate the effects of these reagents on seven polymers (PS, PE, PET, PP, PA, PVC, and PLA), this study employed µFTIR, laser diffraction-based particle size analysis, as well as TD-Pyr-GC/MS. Furthermore, the study discussed issues and inconsistencies with the Fenton reactions reported in the literature in previous validation efforts. The findings of this study suggest that both H<sub>2</sub>O<sub>2</sub> and Fenton reactions are most effective in terms of organic matter removal from microplastic samples while not affecting the tested polymers, whereas KOH dissolved most PLA and PET particles. |
topic |
microplastics wastewater Fenton reaction hydrogen peroxide digestion methods sample preparation |
url |
https://www.mdpi.com/2073-4441/12/9/2445 |
work_keys_str_mv |
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1724516771063398400 |