Analysis of Nanoplastics and Microplastics in Food

Leo M.L. Nollet, Khwaja Salahuddin Siddiqi, Leo M.L. Nollet, Khwaja Salahuddin Siddiqi

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9781138600188
• eBook ISBN: 9780429891229
• Topic: Physical Sciences
• Subtopic: Environmental Science

The world's ever increasing use of plastics has created large areas of floating plastic waste in the oceans—so-called plastic soup. This floating plastic debris is gradually fragmenting into smaller particles which eventually become microplastics, and even nanoplastics.

Analysis of Nanoplastics and Microplastics in Food compiles data on nanoplastics and microplastics in food. To date, there is some data on this, particularly for the marine environment. Fish show high concentrations, but because microplastics are mostly present in the stomach and intestines, they are usually removed and consumers are not exposed. But in crustaceans and bivalve molluscs like oysters and mussels, the digestive tract is consumed, so there is some exposure. Microplastics have also been reported in honey, beer, and table salt.

Key Features:

• Discusses sampling and analysis of nano- and microplastics
• Details the impacts of plastic residues in diverse compartments of the environment
• Includes a discussion of microplastics in freshwater
• Discusses interactions of microplastics and POPs

This book brings to light the reality—and dangers—of microplastics in food. Pollutants like polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) can accumulate in microplastics. Some studies suggest that, after consuming microplastics in food, these substances may transfer into tissues. So, it is important to estimate the average intake. Since engineered nanoparticles (from different types of nanomaterials) can enter human cells, this reality can pose consequences for human health.

Also available in the Food Analysis and Properties Series:

Mass Spectrometry Imaging in Food Analysis, edited by Leo M. L. Nollet (ISBN: 978-1-138-37069-2)

Proteomics for Food Authentication, edited by Leo M. L. Nollet and Semih ?tle? (ISBN: 978-0-367-20505-8)

Food Aroma Evolution: During Food Processing, Cooking, and Aging, edited by

Matteo Bordiga and Leo M. L. Nollet (ISBN: 978-1-138-33824-1)

For a complete list of books in this series, please visit our website at:

www.crcpress.com/Food-Analysis--Properties/book-series/CRCFOODANPRO

Section IV

Sampling and Analysis

Chapter 7

Sampling, Isolating and Digesting of Microplastics

Leo M. L. Nollet

Contents

7.1Sampling

7.1.1Field-Collected Organisms

7.1.1.1Microplastic Losses during Field Sampling

7.1.1.2Microplastic Accumulation during Field Sampling

7.1.1.3Sample Storage

7.1.2Laboratory-Exposed Organisms

7.2Isolating Microplastics

7.2.1Dissection

7.2.2Depuration

7.3Digestion

7.3.1Nitric Acid

7.3.2Other Acids

7.3.3Alkalis

7.3.4Oxidizing Agents

7.3.5Sodium Hypochlorite

7.3.6Enzymes

7.3.7Effect of Temperature

7.4Filtering Digestants

7.5Density Separation

References

A. L. Lusher et al. [1] published an interesting and valuable article on sampling, isolating and identifying microplastics ingested by fish and invertebrates.

7.1 Sampling

7.1.1 Field-Collected Organisms

Micro- and nanoplastics are taken up by a wide range of organisms in a diverse range of habitats, including the sea surface, water column, benthos, estuaries, beaches and aquaculture [2]. The diversity of the organisms and habitats where they live and are sampled require a range of collection techniques [3–5]. The sampling method is determined by the research question, available resources, habitat and target organism. Benthic invertebrate species such as Nephrops norvegicus may be collected in grabs, traps and creels, or by bottom trawling [6,7]. Planktonic and nektonic invertebrates are collected by way of manta and bongo nets [8–11]. Fish species are generally recovered in surface, midwater and benthic trawls, depending on their habitats. Gill nets have been used in riverine systems [12]. Some species are collected from the field by hand; this is common practice for bivalves, crustaceans and annelids [13–17]. Another method is direct collection from shellfish or fish farms [18–20] or from commercial fish markets, where the capture method is often unknown [21–22].

7.1.1.1 Microplastic Losses during Field Sampling

Handling stress, physical movement and the physiological and behavioral specificities of the sampled organism may result in the loss of microplastics prior to animal preservation. Gut evacuation times for animals range from minutes for decapod crustaceans to several hours for calanoid copepods [10] and fish [23,24] to days in larger lobsters [25]. Some animals might egest microplastic debris prior to analysis [7]. In such cases, the time between sample collection and the preservation of the animal must be as short as possible. Care must also be taken to minimize handling stress or physical damage.

The copepod Eurytemora affinis [26] and some fish species have been observed regurgitating their stomach contents [27]. Compression of a catch in the cod end might induce regurgitation in fish [29]. The likelihood of regurgitation increases with depth of capture, and gadoids are more prone to regurgitation than flatfish. Piscivorous predators are prone to regurgitation owing to their large distensive esophagus and stomach [28, 30].

7.1.1.2 Microplastic Accumulation during Field Sampling

Laboratory studies have identified that nano- and microplastics can adhere to external appendages of marine copepods [10]. Cataloguing such interactions in nature is complicated as determining whether the resulting accumulation has occurred naturally or as a by-product of the sampling regimen is difficult. A similar interaction may occur with organisms feeding on microplastics during capture in nets; this is particularly of concern when the mesh size of the net is capable of collecting microplastics, for example, in manta nets (common mesh size 0.33 mm) [23].

7.1.1.3 Sample Storage

It is important how biotic samples are stored. The choice of the preservation technique will largely d...

Table of contents

• Cover
• Half Title
• Series Page
• Title Page
• Copyright Page
• Contents
• Series Preface
• Preface
• Editors
• Contributors
• Section I: Microplastics and Nanoplastics
• Section II: Plastics in the Environment
• Section III: Plastics in Food
• Section IV: Sampling and Analysis
• Section V: Microplastics and POPs
• Section VI: Microplastics in Freshwater
• Index