Reducing the Matrix Effect in Organic Cluster SIMS Using Dynamic Reactive Ionization

Abstract

Dynamic reactive ionization (DRI) utilizes a reactive molecule, HCl, which is doped into an Ar cluster projectile and activated to produce protons at the bombardment site on the cold sample surface with the presence of water. The methodology has been shown to enhance the ionization of protonated molecular ions and to reduce salt suppression in complex biomatrices. In this study, we further examine the possibility of obtaining improved quantitation with DRI during depth profiling of thin film multilayer targets. Using a trehalose film as a model system, we are able to define optimal DRI conditions for depth profiling. Next, the strategy is applied to a multilayer system consisting of the polymer antioxidants irganox 1098 and 1010. This binary mixtures have demonstrated large matrix effects, making quantitative SIMS measurement not feasible. Systematic comparisons of depth profiling of this multilayer film between directly using GCIB, and under DRI conditions show that the latter enhances protonated ions for both components by 4~15 fold, resulting in uniform depth profiling in positive ion mode, and almost no matrix effect in negative ion mode. The methodology offers a new strategy to tackle the matrix effect and should lead to improved quantitative measurement using SIMS. Graphical AbstractCorrespomding author: Hua Tian,

Gas Cluster Ion Beam Time-of-Flight Secondary Ion Mass Spectrometry High-Resolution Imaging of Cardiolipin Speciation in the Brain: Identification of Molecular Losses after Traumatic Injury

“…24 Polymers with m / z above 1000 have been detected as intact protonated/deprotonated ions. 25 The Ar-GCIB has also been successfully used for imaging of biological tissue with satisfactory lateral resolution. 26 The advances in this technique have made lateral resolutions of a few micrometers possible for imaging a metal grid 27 as well as biological samples.…”

A Modified QuEChERS Method for Determination of Pyrethroid Residues in Traditional Chinese Medicine Oral Liquids by High-Performance Liquid Chromatography

“…The matrix effect greatly affects the accurate detection of target compounds in a complex sample. Many methods have been applied to reducing the matrix effect such as the matrix purification method and the special injection method [24,25,26]. However, some methods are difficult to apply due to the higher requirements of instruments and facilities.…”

The evolution of lipidomics through space and time

“…Through rastering the ion beam, an image of the chemical constituents at the surface is generated. In favorable cases, the lateral resolution and sensitivity can detect lipids at attomolar concentrations with resolution at the 50 nm scale [45]. …”