Numerical simulations of gas flows through an open, non-contact cell for LA-ICP-MS

Abstract

Numerical simulations of gas flows through an open, non-contact cell for laser ablation are presented. The cell consists of dual, annular, concentric micro-jet gas arrays to entrain ablated material (the carrier flow) and exclude atmosphere (the curtain flow). This study shows that the design of the cell affords a very high degree of exclusion of atmospheric gases, using a relatively low curtain flow of 2.5 l min À1 (with a carrier flow of 1.2 l min À1 He), and demonstrates the efficacy of the micro-jet arrays in providing an axially symmetric exclusion zone. Minimum particle transit times through the cell were calculated to be of the order of 50-100 ms.

Review of the applications of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to the analysis of biological samples

“…However, signicant changes in the aerosol transport efficiency were not observed for ablation cells with different volumes as well as for different lengths of the transfer lines. 42 The cell design and simulations of the aerosol behavior and its transport were investigated, 41,[43][44][45][46][47] with the purpose of predicting the dispersion of the aerosol and nding the parameters that affect its loss in the ablation cell. The inuence of the sample characteristics must also be considered and the manufacturers of LA systems in general provide cells to accommodate samples of different size.…”

“…The isotopes 43 Ca or 44 Ca were used to normalize the analyte signal in teeth layers [86][87][88] and bone, [89][90][91] but it has been claimed that Ca varies signicantly within the tooth. 92 Sulphur is a keratin matrix element and the isotopes 34 S and 32 S have been effectively used as the IS in the analysis of hair, 93,94 33 S in tortoise shells 95 and 32 S in nails.…”

Aerosol entrainment and a large-capacity gas exchange device (Q-GED) for laser ablation inductively coupled plasma mass spectrometry in atmospheric pressure air

“…Alternatively, a modied open-cell approach was published that allows scanning across the sample surface in a narrow region. 5 A quasi-closed cell design using a gas curtain 16,17 was reported, and it was speculated that a nonperfectly tting sample to cell geometry might contribute to decreased signal stability and slower washout than those obtained when using large and at samples. However, alteration of the sample surface to perfect atness by polishing or cutting is not viable for some archaeological and geological samples.…”

Recent developments in the design of rapid response cells for laser ablation-inductively coupled plasma-mass spectrometry and their impact on bioimaging applications

“…The selection of the smallest cell and identi-cation of the optimal He-Ar gas mixture composition yielded a transient signal of 85 ms at FWHM for U. Following the lead of Bogaerts et al, computational uid dynamics (CFD) modelling based on Reynolds-averaged or Favre-averaged Navier-Stokes models has taken a prominent role in the study and simulation of the aerosol and ow behaviour within the ablation cell and ICP, [11][12][13][14] e.g., for visualizing the pressure gradients and kinetic energy (KE) of the ow in turbulent regions. The visualization of streamlines opens a pathway to improve design aspects of a virtual prototype of an ablation cell by an iterative in silico process, hence optimizing the FD behaviour prior to manufacturing.…”