Detemination of Airborne Microplastics using LC-MS/MS

In recent times, microplastics (MPs) pollution has become a growing concern across the globe. MPs are easily transferred and ubiquitously found in ambient air. These MPs in the air can act as carriers for several toxic pollutants and exposure to MPs could lead to pulmonary diseases in humans. Polyethylene terephthalate (PET) is one of the most abundant airborne MPs in the ambient environements and nylon 66 is one of the most abundant MPs found in microenvironments. However, there are no studies reported for the quantification of airborne PET and nylon 66 microplastics present in inhalable fraction of ambient fine particulate matter. This study describes the methods optimized for the quantification of PET microplastics and nylon 66 microplastics bound to aiborne PM_2.5 using LC-MS/MS. Teflon and Quartz fiber filters were tested for extraction efficiency in measuring the mass concentrations of airborne PET MPs and nylon 66 MPs. Teflon filters have shown good recovery (80 % – 120 %) compared to Quartz filters. Using the optimized methods, a pilot study was carried out at Delhi, the National Capital of India and Mohali, a suburban city in Northwest Indo-Gangetic Plain (NWIGP) for the determination of mass concentrations of PET MPs present in airborne inhalable fraction of ambient PM_2.5 and a pilot study was carried out to measure the mass concentrations of nylon 66 microplastics present in the inhalable fraction of particulate matter collected in a shopping complex. Observed maximum mass concentrations of PET MPs in airborne PM_2.5 at Delhi and Mohali are 135.2 ng m^-3 and 158.0 ng m^-3, respectively. The observed mass concentrations of nylon 66 MPs in the microenvironment in this study are in the range of 0.30 ng m^-3 to 4.37 ng m^-3.