[Back]

W. Nischkauer, F. Vanhaecke, A. Limbeck:
"Self-Aliquoting Micro-Array Plates in combination with Laser Ablation ICP-MS for the direct quantification of challenging liquid samples";
Keynote Lecture: Euroanalysis XVIII, Bordeaux, France; 09-06-2015 - 09-10-2015; in: "Book of Abstracts", (2015), 1 pages.

In inductively-coupled plasma mass spectrometry (ICP-MS), sample introduction of liquid samples is routinely achieved via pneumatic nebulizers. Such nebulizers are appropriate for many commonly analyzed types of liquid matrices, such as drinking water or acid-digested solid samples. However, when introducing more challenging liquid samples (e.g., sea-water, wine, blood, or electrolyte solutions), great care has to be taken to avoid nebulizer-failure due to blocking.
Therefore, alternative sample-introduction strategies are required to provide high throughput, even for the abovementioned challenging matrices. Dried-droplet laser ablation ICP-MS is such an alternative. There, a droplet of liquid sample (typically several μL) is deposited on a solid surface, the liquid is evaporated and the remaining solid residue is ablated with a laser. The dry aerosol thus obtained is brought to the ICP-MS and analyzed. The bottleneck of dried-droplet laser ablation is the deposition of liquid sample droplets. In most reports of dried-droplet laser ablation, this aliquoting step is achieved manually via Eppendorf pipetts. Due to manual handling, the resulting dried residues are quite randomly distributed across the surface of the sample target. This random distribution prevents straight-forward localization of the residues with the laser system.
In this contribution, self-aliquoting micro-array plates are used in combination with laser ablation ICP-MS to automatically split a liquid sample into reproducible aliquots. The advantage of such micro-array plates is that dry residues are obtained in a fast and straight-forward way and that the residues are distributed in a well-defined grid pattern across the surface, facilitating localization and laser ablation.

LA-ICP-MS, self aliquoting micro-array plates, elemental analysis, dried droplet analysis