Determination of mass concentrations of airborne PET microplastics using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)†

Abstract

Microplastics (MPs) have recently become a growing environmental pollution concern. MPs are easily transferred and ubiquitously found in ambient air. MPs in the air can act as carriers for several toxic pollutants, and exposure to MPs can lead to pulmonary diseases in humans. Polyethylene terephthalate (PET) is one of the most abundant MPs used in the manufacturing of various fibres and plastics. In this study, we present a method for the determination of mass concentrations of PET MPs in the airborne inhalable fraction of fine particulate matter (PM_2.5) using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Teflon and quartz fiber filters were tested for extraction efficiency in measuring the mass concentrations of airborne PET MPs. Teflon filters showed good recovery (80–120%) compared to quartz fiber filters. Using this method, a pilot study was carried out in Delhi, the national capital of India, and Mohali, a suburban city in the northwest Indo-Gangetic Plain (NWIGP), for the determination of mass concentrations of PET MPs present in airborne PM_2.5. The observed maximum mass concentrations of PET MPs in airborne PM_2.5 in Delhi and Mohali are 135.20 ng m⁻³ and 157.98 ng m⁻³, respectively.