Objective To establish a method for the quantitative determination of polystyrene (PS) nanoplastics in biological tissue samples by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS).
Methods Different digestion solutions, protein precipitants, and instrument detection parameter systems were compared and optimized to determine pretreatment and determination method for PS plastics in biological samples. We determined the method characteristic indicators (including detection limit, quantification limit, precision and accuracy) by conducting experimental studies, and carried out actual sample measurements based on the method.
Results In this study, a Py-GC/MS method was established for the detection of rat liver and lung tissue samples after digestion with 10% potassium hydroxide solution and precipitation of anhydroethanol protein. PS had a good linear relationship within the range of 0.05-2.00 μg, with a correlation coefficient of 0.999, and the limit of detection and the limit of quantification were 0.012 and 0.036 μg/g, respectively. When the spiking level of PS was low (2 μg/g), medium (10 μg/g), or high (30 μg/g), the recovery rates were 68.0%-85.0%、80.0%-105% and 62.0%-93.1%, respectively, and the relative standard deviation ranged from 7.8% to 15.2%.
Conclusion The method established in this study meets the methodological requirements and can provide a reference for the detection of other biological samples and other types of microplastics, laying a technical foundation for further population exposure level and health risk assessment of nanoplastics.
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