Method development and acquisition parameter optimization for single pulse resolved quadrupole LA-ICP-MS multielement analysis

Abstract

In recent years, there have been significant developments in laser ablation technology. Ablation cells that enable fast aerosol washout in the millisecond range have been developed, which provides the possibility for high pixel acquisition rates in spatially resolved ICP-MS analyses. However, only ToF-ICP-MS instruments that cover the whole m/z range in each data point can exploit this benefit for fast and spatially resolved multielement analysis. With conventional quadrupole ICP-MS instruments, only one data point for each duty cycle is provided. Therefore, the spatial representation is typically calculated from transient quasi-continuous signals using the scan speed of the laser and predetermined aerosol washout times. However, using this conventional approach can lead to reduced image quality including imaging artifacts, such as pixel bleeding, image blur, or distortions. This is because the washout times may not be correctly determined or may change during the analysis of a heterogeneous sample. To solve these issues, single pulse-resolved quadrupole ICP-MS acquisition is proposed. Achieving multielement analysis with a sequential quadrupole ICP-MS requires optimized settling and dwell times depending on the aerosol washout from single laser pulses. This work explores the basic requirements for successfully performing multielement analysis in single pulse-resolved quadrupole LA- ICP-MS measurements with fast washout cells. Washout times, transient signal durations, and acquisition parameters are systematically investigated to determine the multielement capability and limitations regarding the effect on accuracy and precision. The developed approach is applied on different micro-structured materials.