a) Model Pd-doped nanoplastics were diluted in MilliQ, where spikes above the baseline correspond to individual nanoplastics through sp-ICP-TOFMS analysis. Insert: Pd isotopic abundances in the nanoplastics were in line with naturally occurring Pd abundances, where Pd was distributed over six stable isotopes: 102 Pd (1.02%), 104 Pd (11.14%), 105 Pd (22.33%), 106 Pd (27.33%), 108 Pd (26.46%) and 110 Pd (11.72%). Because 106 Pd and 108 Pd are the two most abundant isotopes, these were used as markers for identifying Pd-nanoplastics in subsequent experiments. b) 106 Pdsignal intensity frequency distribution of the Pd loading across the nanoplastics population. A log normal distribution was fitted to the data yielding an average value of 32 ± 7 counts for each nanoplastics event.

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... The Royal Society of Chemistry 2023 nanoplastics in single-particle mode and to streamline the data processing for nanoplastics-only events. Using a dilute suspension of nanoplastics (approx. 1 × 10 5 particles per mL), the individual nanoplastics were recognized as spikes above the baseline, corresponding to number of nanoplastics in suspension (Fig. 2a). All Pd isotopes were detected in one particle with signal intensities proportional to natural Pd isotope abundances (Fig. 2a, insert). Because 106 Pd and 108 Pd are the two most abundant isotopes, these were used as markers for the identification of the nanoplastics for the rest of the analysis. Different pulse intensities were ...

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... events. Using a dilute suspension of nanoplastics (approx. 1 × 10 5 particles per mL), the individual nanoplastics were recognized as spikes above the baseline, corresponding to number of nanoplastics in suspension (Fig. 2a). All Pd isotopes were detected in one particle with signal intensities proportional to natural Pd isotope abundances (Fig. 2a, insert). Because 106 Pd and 108 Pd are the two most abundant isotopes, these were used as markers for the identification of the nanoplastics for the rest of the analysis. Different pulse intensities were observed for each nanoplastics particle, which was likely due to a slightly different Pd loading in each particle and/or some particle ...

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... pulse intensities were observed for each nanoplastics particle, which was likely due to a slightly different Pd loading in each particle and/or some particle agglomeration during dilution. From the pulse intensities measured across >18 000 nanoplastics events, with intensities ranging from 10 to >500 counts, a signal intensity histogram was built (Fig. 2b) to assess the average Pd loading per particle. Here, a log-normal fit was applied to the histogram yielding an average signal intensity of 32 ± 7 counts. Although the fit did not exhibit an ideal match with the data, indicating some deviations from the log-normal distribution, the majority of the nanoplastics presented a central signal ...

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... gradually decreased between successive measurements replicates, indicating cells settling over time, which did not allow for the measurement of a homogeneous suspension. However, when the syringe pump was rotated vertically, the force of gravity prevented cell settling and a consistent number of cells were observed between replicate measurements (Fig. S2 ...

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... sensitivity for carbon, prevented their detection and thus reinforces the need to explore alternative approaches such as using metal signals as proxies for the nanoplastics. Consequently, here Pd-signals were used as proxy for individual nanoplastics detection. Subsequently, based on the average signal intensity measured for each nanoplastics (Fig. 2b), the magnitude of the nanoplastics spike intensity associated with each cell served as a surrogate to determine the approximate number of nanoplastics associated with each cell (Table S3 †). Consistent with previous results, a higher number of nanoplastics were associated with higher exposure doses. However, large standard deviations ...