The analysis of nano-micro nuclear particles has attracted significant attention due to the crucial role of their elemental and isotopic characteristics in tracing the origins of particulate matter and assessing its potential risks to human health and the environment.However,challenges persist in obtaining accurate and consistent element profiles and ratios for small-sized nanoparticles due to their low level and the transient nature.In this study,a high-speed digital oscilloscope was integrated with multiple collector inductively coupled plasma mass spectrometry(MC-ICP-MS)to develop a high time-resolution"Event-triggered signal capture"(ETSC)system for single particle analysis.This innovative approach enabled the analysis of element/isotope within rare earth nanoparticles at ag-fg level.The ETSC accurately recorded the complete profile of single particle,event captured by the electron multiplier with nanosecond time resolution,allowing for high-sensitivity element analysis and high-precision isotope analysis of single particles.The results demonstrated that the ETSC system could achieve quantitative analysis of ag levels of ytterbium(Yb)in 50-nm rare earth-doped particles,with a detection limit as low as 38 ag for Yb.Moreover,the isotopic precision of single particle analysis for 173/171Yb could reach 0.047(standard deviation),and the standard error for isotopic analysis of multiple particles could achieve a level of 2‰-3‰(permil)for 173/171Yb.Finally,the capability of ETSC system to analyze environmental samples was demonstrated through the analysis of doped ytterbium oxide nanoparticles.All these findings demonstrated that the ETSC provided a unique method for elemental and isotopic analysis of single nuclear particles.