Determination of gold nanoparticles in natural water using single particle-ICP-MS

A reliable method for detecting nanoparticles is necessary for the wide application of nanomaterials. Single particle-inductively coupled plasma mass spectrometry（SP-ICP-MS） was investigated to detect the size of gold nanoparticles（Au NPs） in this work. Discrimination of particle signal and iterative algorithm were used to calculate the baseline of particle signal. Influence of dwell time was discussed and 3 ms was selected as dwell time for size detection. Different Au NPs standards（30, 60, 80 and 100 nm） and mixed samples（60 and 100 nm） were determined by SP-ICP-MS and the accuracy was confirmed with reference values. The particle size detection limit was 19 nm in ultrapure water（UP water） and 31 nm in 0.1 μg/L Au^3＋ solution. Stability of Au NPs in ultrapure water and natural water samples was investigated by detecting size variation of AuN Ps. The result shows that Au NPs are stable in aqueous environment for 6 d but degraded after 30 d.