Application of SS-CS-HR-AAS measurements for the detection of Ag nanoparticles in marine invertebrates

Abstract

The aquatic fate of NPs governs the ecotoxicity in the aquatic environment and marine organisms. The present study describes the development of t for purpose analytical procedure for the determination of Ag NPs in different marine organisms by Solid Sampling Continuous Source High Resolution Atomic Absorption Spectrometry (SS-CS HR-AAS). The detection is based on the observation of the Ag absorption peak and its atomization delay t ad , i.e., the time at which the maximum absorbance is observed. Indeed, the presence of Ag NPs is easily detected through the analysis of t ad as Ag ions and Ag NPs have different interactions with the sample matrix and different t ad . The method was rst developed using biota CRMs (DORM-3 and SRM 2976) spiked with Ag NPs standard solutions of different sizes (10, 20, 40 and 60 nm) or ionic Ag (Ag + ) at the same concentrations. The temperature program was optimized in order to achieve the maximum difference between the t ad obtained for Ag + and the one obtained for Ag NPs (Δt ad ). Then, laboratory experiments were performed on mussels and marine sponges, two different marine invertebrates. The results showed that the developed methodology is suitable for the detection of Ag NPs for both groups of organisms, showing Δt ad up to 3.1 s. The behavior can be slightly different from matrix to matrix but a clear separation between ionic Ag and Ag NPs is always visible. The developed analytical method is therefore a promising tool to assess the presence of Ag NPs in marine invertebrates.