Investigation of tin adsorption on silica nanoparticles by using flow field-flow fractionation with offline inductively coupled plasma mass spectrometry

Flow field-flow fractionation (Fl-FFF) for silica nanoparticles with offline inductively coupled plasma mass spectrometry (ICP-MS) was applied to investigate the adsorption behavior of tin onto silica nanoparticles. Effect of carrier solutions and membranes was studied to achieve better separation for silica nanoparticles prior to tin detection using ICP-MS. Investigation was carried out by using 0.25 mM ammonium carbonate and 0.02% Gamma L-70 with 0.02% NaN3 as carrier solutions with 1 kDa regenerated cellulose (RC), 10 kDa regenerated cellulose (RC), and 10 kDa polyethersulfone (PES) membranes. Ammonium carbonate carrier solution with suitable ionic strength provided good separation with minimization of particle-membrane interaction. Better retention was shown by employing 10 kDa RC membrane. Furthermore, Fl-FFF was employed for the separation of silica nanoparticles incubated with tin. Fractions eluted from Fl-FFF were collected and then introduced into ICP-MS. Tin was adsorbed onto silica nanoparticles with different adsorption capabilities depending on particle size. Adsorption of tin was greater on the smaller size of silica nanoparticles compared to the bigger size with the adsorption percentage of 98.5, 44.9, and 6.5 for 60 nm, 100 nm, and 200 nm, respectively. Size-dependent adsorption of tin was in good agreement with surface area per volume of silica nanoparticles.