Greenness of analytical methods for isolation and identification of microplastics in environmental and food samples - A critical review

Efforts to standardize microplastic extraction methods for environmental and food samples have often overlooked their environmental impact and sustainability. This study comprehensively reviews various analytical methods and assesses their sustainability using the Analytical GREEnness calculator. Toxic chemical usage was found to have the greatest impact, rendering in situ and chemical-free analysis the most sustainable method. Conversely, multi-step pretreatment involving chemical use was deemed the least sustainable. Selective sampling and micro/spectroscopy were identified as greener options than bulk sampling and thermal analysis, respectively. Magnetic/electrostatic separation has emerged as an optimal method for routine analysis, while solvent extraction is suitable for precise and extensive research purposes. For enhanced sustainability, it is crucial to replace, reduce, and reuse hazardous reagents. Additionally, promoting miniaturization, automation, and in situ imaging methods for routine monitoring of microplastics in environmental and food samples is essential for advancing green practices.