# Characterization of Nanoparticle Batch-To-Batch Variability
## 3 Results
### Overall Observations from the Physicochemical Characterization of NM Batches
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Physicochemical** & **Silica NMs** & **Silica NMs** & **Zine Oxide NMs** & **Tilanium Dioxide NMs** & **Amine-Modified Polystyrene NMs** & **Cerium Dioxide NMs** \\
**Parameter** & **(Stober Synthesis)** & **(Hame Synthesis)** & **Zine acetate** & **Constrations of** & **Reducing agent and** \\  & Concentration of NH\({}_{3}\) & **TECS concentration in** & **Zine acetate** & **preH value and temperature** & **Achössicobutyronitrile** & **Reducing agent and** \\  & and aqueous & & **conditions** & & & \\  & ammonium & & **conditions** & & & \\  & & & & & & \\ \hline Number of batches & 8 & 6 & 9 & 8 & 6 & 9 \\ \hline Trace impurities & Up to 67 ug/g (Al) & Up to 75 ug/g (Al) & Up to 1080 ug/g & Up to 96 mg/g (Na) & 42 to 113 ug/g (Na) & 87 to 187 ug/g (Ca) \\  & & & (Fe, Ca, Na and S6) & & & \\ \hline Dissolution in water & n.d. & 6 to 10 wt \% & 7 wt \% & n.d. & n.d. \\ \hline Crystal structure & Amorphous & Amorphous & Crystalline hexagonal & Crystalline anatase with a & Amorphous & Crystalline cubic lattice \\  & & & & & \\  & & & & & \\ \hline Crystall size & – & – & 20 to 30 nm & 4.5 to 6 nm & – & 5 to 8 nm \\ \hline Mobility diameter & 33 to 118 nm & 32 to 160 nm. & 25 to 55 nm & 33 to 70 nm. & 88 to 170 nm. & 40 to 74 nm. \\ \hline Hydrodynamic diameter (DLS) & 25 to 120 nm & 200 to 380 nm & 130 to 900 nm & 60 to 280 nm & 105 to 150 nm & 63 to 146 nm \\ \hline Zeta potential & –45 to -66 mV & –15 to -18 mV & –15 to +24 mV & +33 to +40 mV & +44 to +50 mV & +30 to +49 mV \\ (surface charge) & (pH 8.4 + 0.57) & (pH 4-3) & (pH -6) & (pH -10) & (pH 6.1) & (pH 3.8 to 6.1) \\ \hline Photocatalytic activity & No & No & High & Low & No & No \\ \hline Orland-water partition coefficient & Not analysed & \textless{detection limit} & \textless{detection limit} & \textless{detection limit} & \textless{detection limit} & \textless{detection limit} \\ \hline Radical formation & 2-42.4-fold of control & 2-6.2-fold of control & 3- 4-fold of control & 1-4.8-fold of control & 3.2- 4.2-fold of control & 2- 12-fold of control \\ \hline Physicochemical characterization data sheets & Supplementary Supplementary & Supplementary & Supplementary & Supplementary & Supplementary \\ Materials document S2 & Materials document S3 & Materials document S4 & Materials document S5 & Materials document S6 & Materials document S7 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summarized physicochemical parameters characterized for the five selected priority nanomaterials (NMs), highlighting the B2B variability. The DCF fluorescence induced by reactive oxygen species (ROS) showed a concentration-dependent increase with most NM samples. In the summary reports only the values at the highest NM concentration (400 \(\upmu\)g/mL) are shown to provide a better overview and comparison between the different batches and 0.3 \(\upmu\)M H\({}_{2}\)O\({}_{2}\) was used as a positive assay control. Except for the flame-synthesized silica NMs (all samples), no detectable presence of NMs was found in the organic phase. Note, however, that there are challenges in the use of this method for NMs as shown by [PERSON] et al. [36].