- An interlaboratory comparison study on the analysis of gold nanoparticles (AuNPs) among members of the working group 4 (engineered nanomaterials) (http://www.norman-network.net/?q=node/54) within the NORMAN network and members of the COST Action ES1205 ENTER (www.es1205.eu) was conducted. The nanomaterials under investigation were gold nanoparticle suspensions (Au NP) with Au NP sizes of 10, 50 and 250 nm. Three monomodal samples and two mixtures (bi- and trimodal) out of the single sized Au NP standards were prepared as (artificial) samples and sent to the attendees for analysis. The aim of the interlaboratory test was to investigate, if comparable data in terms of easy to handle nanomaterials and different analytical techniques can be obtained and, if the current EU definition recommendation for the term nanomaterial is implementable. Each attendee was free to decide which sample preparation protocol and technique to apply - no strict rules were defined. Upon a previous survey by means of a questionnaire the available lab equipment of the attendees was assessed. Also based on accessible lab equipment it was asked for following parameters to be analyzed: i) total concentration of gold in each sample, ii) size distribution of Au NPs in the monomodal samples and in the mixtures, iii) based on the data obtained, decision whether the mixture can be allocated to nanomaterial or not according to the EU definition recommendation [1]. This report compiles the obtained results and findings are discussed in a comparative manner. Pros and cons of the applied techniques are highlighted.
