Automated Robotic System for Sample Preparation and Measurement of Heavy Metals in Indoor Dust Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

Abstract

Dust is ubiquitous in our daily environment-outdoor and indoor. In modern times, people often spend the majority of their time at home, in offices, at work or in schools. Suspended particles such as tiny crumbs up to long fibers generate indoor dust deposits. Inhouse sources are the interior releasing abraded fibers from carpets, bedding and clothing as well as the human itself distributing skin cells, lost hairs and food residues. External sources are finest sand, pollen, exhaust particles and microorganisms (e.g., dust mites). An exposure to heavy metals in certain concentrations may affect the human health and may lead to intoxication, allergies or carcinogenic effects. The heavy metals amount in indoor dust depends on the environmental conditions, requiring a sampling with adequate sampling points and numbers. High sampling numbers ensure good coverage of the area to be examined. Therefore, fast and reliable measurement methods for identification and quantification of the elemental composition are needed. To meet these requirements, a robotic system for automated sample preparation and determination of heavy metals in indoor dust using ICP-MS was developed. The values for repeatability, recovery rate, withinlaboratory precision, measurement precision and the limits of detection and quantification were determined for both, the manual and the automated process. Furthermore, the individual process steps and times were compared. Besides the processing of certified reference material, inhouse dust samples from different origin were prepared and measured to give a first overview of the inhouse dust composition. The results show, that the robotassisted system is well-suited for the heavy metal screening in indoor dust.