“…Briefly, the whole analytical run cycle consist of three on-line steps: (I) focusing/relaxation of AgNPs and isolation of Ag(I) species, (II) fractionation, characterization, and quantification of AgNPs, and (III) quantification of Ag(I) species. Given that particle retention in HF5 is dependent on the size, the particle size or size distribution of the target particles can be calculated with standard particles (e.g., AuNPs). , Considering the material-dependent retention behavior possibly due to the particle–particle and particle–accumulation-wall interactions, in step II the AgNPs size was obtained with a calibration curve obtained by plotting t R measured under the same fractionation conditions against the known size of standard AuNPs (Figure S2A), the acceptable standard metallic NPs, from ICPMS fractograms of the Au ( 197 Au) and Ag ( 107 Ag) signals (Figure S2B), and concentrations of fractioned AgNPs were acquired by ICPMS (7700 series, Agilent Technologies, Palo Alto, CA). Free Ag(I), newly formed Ag(I) complex, and AgNPs with diameter less than the HF pore size, namely, tiny AgNPs, could be quantified respectively as follows: Free Ag(I) ions or weak Ag(I) complexes adsorbed onto the Amberlite IR120 resin through ion-exchange with Na + in minicolumn concentration (MCC) during step I were desorbed by Na 2 S 2 O 3 and quantified by ICPMS detector in step III.…”