Ultrasonic Extraction-Single-Particle Inductively Coupled Plasma Mass Spectrometry for Analysis of Metal Nanoparticles in Seawater Sediments

Accurate analysis of metal nanoparticles (MNPs) in sediments is a prerequisite for assessing the ecological risks of MNPs in aquatic environmental sediments. In this study, an analytical method for quantitative detection of concentration and particle size distribution of silver-containing nanoparticles (Ag-NPs), zinc-containing nanoparticles (Zn-NPs), cerium-containing nanoparticles (Ce-NPs), and titanium-containing nanoparticles (Ti-NPs) in sediments was established based on ultrasonic extraction-single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). The effects of sample preparation conditions such as extraction solvent type, solid-liquid ratio, ultrasonic time, and settling time on the recovery of MNPs were investigated. The results showed that the extraction of MNPs from sediment by distilled water could effectively eliminate the high background signal interference introduced by the extractant under the conditions of solid-liquid ratio of 1:400 (g:mL), ultrasonic extraction time of 1 h and settling time of 3 h. The detection limits for particle size of Ag-NPs, Zn-NPs, Ce-NPs and Ti-NPs in sediments were 31, 35, 26 and 85 nm, respectively, while the detection limits of particle concentrations were 1.21x10(4), 1.90x10(4), 5.26x10(7) and 1.48x10(7) particles/g, respectively. The spiking recoveries of Ag-NPs, Zn-NPs, Ce-NPs and Ti-NPs in sediments were 62.1%-108.7%, with relative standard deviations below 10%. This method could rapidly, accurately and simultaneously determine the concentration and particle size distribution of various MNPs in sediments, and was successfully applied to analysis of Ag-NPs, Zn-NPs, Ce-NPs, and Ti-NPs in authentic marine sediments.