Articles | Volume 10, issue 5
https://doi.org/10.5194/amt-10-1823-2017
https://doi.org/10.5194/amt-10-1823-2017
Research article
 | 
16 May 2017
Research article |  | 16 May 2017

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

Marin S. Robinson, Irena Grgić, Vid S. Šelih, Martin Šala, Marsha Bitsui, and Johannes T. van Elteren

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.

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Short summary
Knowing the size and elemental composition of airborne particles is necessary to understand their impact on human health. A widely used instrument for collecting size-segregated particles is the multi-orifice uniform deposit impactor (MOUDI). Laser ablation ICP-MS in imaging mode provided multi-elemental analysis of size-segregated particles with excellent sensitivity. The maps generated offered insights regarding the uniformity of the elemental distribution.