Assessment of microplastics in personal care products by microscopic methods and vibrational spectroscopy

Primary microplastics, known as microbeads (mu Bs), are found in personal care and cosmetic products (PCCPs) being used as an ingredient for physical abrasion on human body surface. Due to the fact that mu Bs has sizes less than 0.8 mm, sometimes even less than 0.1 mm, they can be ingested by many organisms, being transmitted in the food chain. The development of a method for isolating the microplastics from the matrix of branded PCCPs samples (i.e., shower gel, body spray) using ultrasound technique at constant temperature and pressure, high-performance vacuum filtration method with various high-purity filtration membranes (e.g., cellulose) was the first objective of this study. The second objective was to combine vibrational spectroscopy techniques (i.e., Fourier-transform infrared mu-spectroscopy) with optical microscopy, to investigate the morphology and chemical composition of MPs. Microplastics were identified in all five brands of analyzed products. Thus, an average value of 420 mu Bs/100 g in shower gel and 200 mu Bs/100 mL in body sprays was determined; the identified colors were black (mostly), blue, yellow, brown, green, and red. The observed sizes varied from tens of micrometers to a few centimeters in some cases and the thickness reached 10 mu m. From visual (microscopy) and chemical (mu-FTIR spectroscopy) point of view the structure was mostly like polypropylene fibers, smaller and having glossy mate appearance.