Laser ablation ICP-MS of size-segregated atmospheric particles collected with a MOUDI cascade impactor: a proof of concept

Marin S Robinson,Johannes T Van Elteren,Vid S Šelih,Marsha Bitsui,Martin Šala,Irena Grgić

doi:10.5194/amt-10-1823-2017

Marin S Robinson, Johannes T Van Elteren + Show 4 more

Open Access

https://doi.org/10.5194/amt-10-1823-2017

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Abstract

Abstract. A widely used instrument for collecting size-segregated particles is the micro-orifice uniform deposit impactor (MOUDI). In this work, a 10-stage MOUDI (cut-point diameter of 10 µm to 56 nm) was used to collect samples in Ljubljana, Slovenia, and Martinska, Croatia. Filters, collected with and without rotation, were cut in half and analyzed for nine elements (As, Cu, Fe, Ni, Mn, Pb, Sb, V, Zn) using laser ablation ICP-MS. Elemental image maps (created with ImageJ) were converted to concentrations using NIST SRM 2783. Statistical analysis of the elemental maps indicated that for submicron particles (stages 6–10), ablating 10 % of the filter (0.5 cm2, 20 min ablation time) was sufficient to give values in good agreement (±10 %) to analysis of larger parts of the filter and with good precision (RSE < 1 %). Excellent sensitivity was also observed (e.g., 20 ± 0.2 pg m−3 V). The novel use of LA-ICP-MS, together with image mapping, provided a fast and sensitive method for elemental analysis of size-segregated MOUDI filters, particularly for submicron particles.

Highlights

Inhalation of particle-bound metals in atmospheric particulate can negatively impact human health (Chen and Lippmann, 2009)
Filters are typically extracted with acid and analyzed by ICP-MS (Canepari et al, 2008; Herner et al, 2006; Li et al, 2012; Ntziachristos et al, 2007; Pekney et al, 2006) or ICP-AES (Fang and Huang, 2011), whereas in some cases direct analysis of the filters was performed by X-ray fluorescence spectrometry11 or proton-induced X-ray emission (Brüggeman et al, 2009)
The variability in the direction of continental winds on the 2 days of sampling may have influenced this signal. In this proof-of-concept paper, we have demonstrated the usefulness of LA-ICP-MS as a tool for analyzing the elemental composition of size-segregated atmospheric particles collected on filter-based media

Summary

Introduction

Inhalation of particle-bound metals in atmospheric particulate can negatively impact human health (Chen and Lippmann, 2009). Filters are typically extracted with acid and analyzed by ICP-MS (Canepari et al, 2008; Herner et al, 2006; Li et al, 2012; Ntziachristos et al, 2007; Pekney et al, 2006) or ICP-AES (Fang and Huang, 2011), whereas in some cases direct analysis of the filters was performed by X-ray fluorescence spectrometry or proton-induced X-ray emission (Brüggeman et al, 2009) Detection limits using these methods are challenging due to low particle mass and contamination risks; after corrections have been made for blanks, elemental concentrations are often below detection limits (Pekney et al, 2006)

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