A method based on asymmetric flow field flow fractionation hyphenated to inductively coupled plasma mass spectrometry for the monitoring of platinum nanoparticles in water samples

An analytical methodology based on asymmetric flow field flow fractionation hyphenated to inductively coupled plasma mass spectrometry (AF4-ICP-MS) has been developed for monitoring citrate coated platinum nano-particles (PtNPs) of different sizes (5, 30, and 50 nm) in water samples. Several factors have been optimized, such as carrier composition, AF4 separation program, focusing step or cross flow values. Under the optimum conditions, PtNPs can be fractionated in about 30 min in a single run with quantitative recoveries of the membrane (100 +/- 7%, n = 5). The optimized method has been successfully applied to study transformations, not only in size but also surface modifications, of PtNPs in synthetic and natural water samples over time. The effect of organic matter was specifically studied, and it was found to be a critical parameter. The analytical strategy followed in this work can be very useful to develop further environmental studies involving PtNPs.

Automated summary

An analytical methodology based on AF4-ICP-MS was developed to monitor citrate-coated PtNPs in water samples. The method was optimized to study transformations of PtNPs in synthetic and natural water samples, with a focus on the impact of organic matter. The optimized method demonstrated quantitative recoveries of PtNPs and is promising for further environmental studies of PtNPs.