The agglomeration state of nanosecond laser-generated aerosol particles entering the ICP

Abstract

Fundamental understanding of aerosol formation and particle transport are important aspects of understanding and improving laser-ablation ICP-MS. To obtain more information about particles entering the ICP, laser aerosols generated under different ablation conditions were collected on membrane filters. The particles and agglomerates were then visualised using scanning electron microscope (SEM) imaging. To determine variations between different sample matrices, opaque (USGS BCR-2G) and transparent (NIST SRM 610) glass, CaF(2), and brass (MBH B26) samples were ablated using two different laser wavelengths, 193 and 266 nm. This study showed that the condensed nano-particles ( approximately 10 nm in diameter) formed by laser ablation reach the ICP as micron-sized agglomerates; this is apparent from filters which contain only a few well-separated particles and particle agglomerates. Ablation experiments on different metals and non-metals show that the structure of the agglomerates is matrix-dependent. Laser aerosols generated from silicates and metals form linear agglomerates whereas particle-agglomerates of ablated CaF(2) have cotton-like structures. Amongst other conditions, this study shows that the absorption characteristics of the sample and the laser wavelength determine the production of micron-sized spherical particles formed by liquid droplet ejection.

Phenomenological studies on structure and elemental composition of nanosecond and femtosecond laser-generated aerosols with implications on laser ablation inductively coupled plasma mass spectrometry

“…Helium and argon have about six times lower breakdown voltage than air [31] and could therefore cause problems due to discharging in the sampler. However, size and shape of the aerosols were shown to be widely independent of the carrier gas when comparing helium and argon [32]. Therefore sampling with air as carrier gas is assumed to be suitable for these aerosol studies.…”

Multiple trace element analyses for silicate minerals and glasses by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

“…into which different elements were selectively partitioned on the basis of volatility, and ( 2 ) differential volatilization of elements during incomplete volatilization of the microparticles in the ICP ( see also Koch et al, 2002Koch et al, , 2004Kuhn and Günther, 2005 ) . The absolute degree of fractionation that occurs during ablation is highly dependent on numerous factors, including the Fig.…”

The influence of carrier gas in the analysis of alumina by laser ablation inductively coupled plasma mass spectrometry

“…Due to He carrier gas, sample transport efficiency may increase or the generated particle size distribution may decrease [12][13][14][15][16]. But the previous investigations about LA parameters have been accomplished only for glass [17][18][19]. Alumina is the most representative refractory material that has high hardness and insulation performance.…”