Advancing pyrolysis-gas chromatography-mass spectrometry for the accurate quantification of micro- and nanoplastics in human blood

Quantification of micro- and nanoplastics (MNPs) in human samples is essential for accurately assessing human exposure and understanding the potential health impacts of these pervasive pollutants. Blood plays a key role in revealing potential MNPs exposure and its health impacts. The detection of MNPs in human blood, however, is analytically challenging due to the complex composition of the sample and the limited availability of sensitive analytical methods. Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) using Selected Ion Monitoring (SIM) has been widely used to quantify MNPs in human blood. In this work the analytical approach was improved by employing full scan data acquisition. The mass concentration of six polymers widely used in plastic materials - poly(methyl methacrylate) (PMMA), polypropylene (PP), polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), and polyethylene terephthalate (PET) – was determined in 102 human whole blood samples. Rigorous QA/QC measures were established which are essential for ensuring the reliability and accuracy of the method. Limits of detection (LODs) ranged from 14 ng/mL (PP) to 245 ng/mL (PE). The recoveries of the quantitation compounds ranged from 52 to 102%. MNPs were detected in all the samples investigated with PVC as the most frequently detected polymer (99% of all samples). For 20% of samples, the concentration was above the limit of quantification (LOQ) with an average total concentration of 386 ng/mL. The analysis of MNPs in human blood is relevant for future research to understand the pathways of MNP absorption, accumulation, and potential health risks associated with exposure to plastic pollutants. The use of full scan data acquisition enabled simultaneous ion monitoring allowing for more careful selection of quantitation compounds and provides the potential for retrospective data analysis.