Development of direct atmospheric sampling for laser ablation-inductively coupled plasma-mass spectrometry

Abstract

Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) represents one of the most popular techniques for direct analysis of solid samples. The 'ease of use' of the technique has attracted particular attention in the past decades, since it offers rapid access to qualitative and quantitative information of components contained within solid samples without the need for sample preparation. However, it requires thorough understanding of the numerous processes involved to improve its capabilities and reduce its limitations. Therefore, the focus of this work was directed towards fundamental studies using LA-ICP-MS and consists of four main topics. As the main focus of this work, the novel sampling method describes laser ablation sampling in ambient air, utilizing aerosol suction and gas exchange prior to the ICP-MS without loosing significant amounts of particles. With the use of a recently developed Gas Exchange Device (GED), various gases can be online exchanged to argon. The gas exchange is based on gas diffusion through a silica membrane. The present prototype of GED is applicable to exchange air at a flow rate of 0.25 L min -1 by Ar at 0.21 L min -1 . This gas flow is significantly lower than the commonly applied flow rate of carrier gases used for LA, however the results obtained are very promising. The efficiency of air exchange to Ar was studied using various factors monitored during measurements. Oxide formation, background count rates and potential spectral interferences generally caused by polyatomic

Review of the State-of-the-Art of Laser Ablation Inductively Coupled Plasma Mass Spectrometry

“…helium/argon) can be accomplished prior to ICP-MS analysis, allowing one to perform LA even under environmental conditions, i.e., humid air without the need for hermetically sealed sampling cells. 8 The general figures of merit of LA-ICP-MS are specified in Table I.…”

Proceedings of the International Conference LACONA XI

“…13). This fluorescence is attributed to significant amounts of fluorescent organic matter contaminants, such as fibers, from the scale's surface; the lack of distinctive peaks could also result from the low Raman activity of magnetite, indicated by SEM as the layer's primary component [51]. The (3) showing the presence of goethite with peaks at 300 cm -1 , 386 cm -1 , and 549 cm -1 .…”

“…Typical LA-ICP-MS systems utilize laser ablation of solids in a neutral gas (argon and/or helium) atmosphere; the possibility to ablate solids in air is reported rarely [51]. While standard set-up is being used, a sample or an object is located in a moveable x-y-z stage and closed in a tightly sealed ablation cell continuously flushed with a carrier gas.…”

Development of the Atmospheric Plasma Soft-Ablation Method (APSA) for Elemental Analysis of Materials on Heat-sensitive Substrates

“…There has been some research concerning the elemental analysis of large-sized samples using LA-ICP-MS coupled with a gas exchange device. [13][14][15] We also do not need to crush a big sample to a smaller, manageable size for introducing it into a chamber, like usual LA-ICP-MS and secondary-ion mass spectrometry (SIMS). Because the entire sampling process takes place under atmospheric pressure, APSA can be coupled to various analytical instruments, such as ICP-MS, ICP-time-offlight mass spectrometers (ICP-TOF-MS), gas chromatographmass spectrometers (GC-MS), or ambient mass spectrometers for any purpose.…”