
Protocol for laboratory analysis of litter particles - Latvia 2023:

Microplastic analysis protocol
Net contents were carefully removed and inspected. Larger organic debris (leaves etc) were examined visually before discarding. Sample was concentrated on a GF (glass fiber) filter and placed into a glass petri dish for closer observation under microscope. Photos of potential plastic particles were taken and size was measured. Particles for FTIR analysis were placed in a vial. All particles were scanned at least once with 32 scans at a time. Those that did not show a match of more than 80% match with databses were analyzed two more times. If sufficient match was not obtained, those particles were categorized as "UNIDENTIFIED". Particles that were of organic materials were excluded. As fibers were too small for FTIR analysis, they were tested by hot needle method to determine if they are plastic or not.

Device used for polymer analysis: Nicolet iS20 FTIR Spectrometer from ThermoFisher

Polymer databases: 
Aldrich Condensed Phase Sample Library
Aldrich Vapor Phase Sample Library
ATR, Microplastics, 2cm-1
Georgia State Crime Lab Sample Library
HR Aldrich Alcohols and Phenols
HR Aldrich Aldehydes and Ketones
HR Aldrich Dyes, Indicators, Nitro and Azo Compounds
HR Aldrich Esters, Lactones, and Anhydrides
HR Aldrich Hydrocarbons
HR Aldrich Organometallic, Inorganic, Silanes, Boranes, and Deuterated Compound
HR Aldrich Phosphorous and Sulfur Compounds
HR Aldrich Solvents
HR Hummel Polymer and Additives
HR Nicolet Sampler Library
HR Polymer Additives and Plasticizers
HR Specta IR Demo
HR Specta Raman Demo
Hummel Polymer Sample Library
JPI MP Spectral Database_1
JPI MP Spectral Database_2
Natural
Organics by RAMAN Sample Library
Plasctic polymers
Sigma Biological Sample Library
Sprouse Polymers by ATR
STJ Spectral Database
Synthetic fibers
Thermo Electron ATR Germanium
Thermo Electron ATR Rubber Zinc Selenide
User Example Library

