Microplastics Sampling Guide

Microplastics
Sampling Guide

Microplastics are generally defined as polymeric particles smaller than 5 mm in size in any one dimension, present in wastewater, rivers, lakes and oceans. Polymers that are derived in nature that have not been chemically modified (other than by hydrolysis) are excluded. Due to the small size, they may not be easily removed during the wastewater filtration processes and can enter the ecosystem, negatively impacting the environment.

The common sources of microplastics are: additives in personal care products, synthetic fibers, resin pellets, tire recycling, medical products, abrasion and exfoliating beads used in furniture and insulation, fragments of larger plastic items as they degrade from the effects of ultraviolet rays and other weathering factors. Microplastics can potentially leach toxic chemicals, including endocrine disruption chemicals, such as bisphenol A and phthalates.

Microplastics Sampling

Water samples may be collected in pre-cleaned 500 ml or 1 liter glass containers with non-plastic lid liners (PTFE is acceptable). Containers should be packaged to avoid breakage during shipment. The use of plastic packing peanuts should be avoided if possible. Shipping samples on ice (<6o ) is preferred, but samples may be shipped at room temperature. Freezing of samples shall be avoided. A 28-day holding time from sample collection to the analysis is allowed.

Soils and similar solid samples may be collected by shovel or applicable device and placed into rinsed glass containers or jars. Whenever possible submit a minimum sample of approximately one liter in volume; however smaller amounts can also be analyzed when sample volume is limited. Beach sand is typically collected along the wrack line which is the point of high tide where sticks and other debris accumulate. This is also the point where the highest concentration of Micro-plastics is usually found.

Food and beverage samples may be submitted in glass jars or, in the case of unopened food or beverages, in their original containers. Food and beverage samples should be shipped on ice (ice packs) in appropriate coolers for maintaining a cool environment during shipping.

Microplastics Analysis

EMSL Analytical, Inc offers multiple reporting styles. The Basic Microplastics Analysis which includes total microplastics count and sizing information obtained by sieving (when applicable) and microscopy. The Full Microplastics Analysis includes the polymer identification with size separation based upon the types of plastics observed. This process is performed by sieving (when applicable), filtration, and analysis by microscopy and Fourier Transform Infrared Spectroscopy (FTIR). Macroplastics (size >5mm), if found during the analysis, are also reported for informational purposes but not included in the sizing data.

Example of a Basic Microplastics Report

Upon request the reporting format can be tailored to meet your needs as well as the size ranges and additional data.

Table 2: Microplastics results for sample 1.

EMSL ID:	36250xxxx-0001
Sample ID:	1
Description:	Water
Amount Analyzed:	500 (ml)
Preparation Parameters	Value	Units	Comments
Sub-sample (prepared):	500	(ml)	A
Effective Filter Area:	1370	(mm2)
Field Area:	1370	(mm2)
No. Fields Analyzed:	1	(No.)
Area Analyzed:	1370	(mm2)
Limit of Detection:	0.0007	(Particles/mm2)
Limit of Quantitation:	0.0020	(Particles/ml)	F
Particle Size Range (µm)	Concentration (Particles/ml)	Percent in Range	Comments
1-5	<LOQ	0.0	B
5-10	<LOQ	0.0	B
10-50	<LOQ	0.0	C
50-100	0.0020	100.0	C
100-500	<LOQ	0.0	C
500-1000	<LOQ	0.0	C,D
1000-5000	<LOQ	0.0	D
>5000	<LOQ	0.0	D,E
Total Microplastics	None Detected	Max. Diameter = 61µm	Max. Length = 73µm
Count by Morphology	(%)		(%)
Spherical	ND	Sheet	ND
Non-uniform	100.0	Fibrous	ND
		Shaving	ND

Comments: LOQ = Limit of Quantitation (see Appendix 2). Sample volume based on particle concentration.

Parameters used in the preparation of the sample.
Presumptive microplastic particles observed by microscopic analysis; complete identification by FTIR cannot be determined because the particle size is below the minimum detection area.
Particles observed by microscopic analysis and identifiable by FTIR.
Particles observed by sieve separation and stereo microscopic analysis and identifiable by FTIR.
Particles larger than the generally accepted definition of microplastics and identifiable by FTIR.
See appendix 2 for calculations.

Basic Microplastics Reports also include images of key microplastics particles observed in each sample.

Full Microplastics Analysis also includes the following.

Additional histograms showing the size ranges and sample composition by common plastic types is available as part of the Full Micro-plastic Analysis.

Microscopic image and associated FTIR spectra of a microplastic particle in a sample compared with the library reference spectrum of polyester (blue trace).