Detection and Characterization of ZnO Nanoparticles in Surface and Waste Waters Using Single Particle ICPMS

Abstract

The increasing production of ZnO nanoparticles (nZnO) makes their analysis and characterization extremely important from an ecological risk perspective, especially at the low concentrations at which they are expected to be found in natural waters. Single particle ICPMS (SP-ICPMS) is one of the few techniques available to detect and characterize nanoparticles at environmentally relevant concentrations. Unfortunately, at the very low particle concentrations where SP-ICPMS is performed, significant dissolution of the nZnO generally increases background levels of dissolved Zn to the point where measurements are not generally possible. By hyphenating SP-ICPMS with an ion-exchange resin, it was possible to characterize and quantify nZnO in order to gain insight into the nature of the nZnO in natural waters. Spiked and unspiked water samples were analyzed using a SP-ICPMS that was coupled to a column containing a strong metal binding resin (Chelex 100). In addition to the detection of ZnO nanoparticles and the determination of a size distribution in natural waters, it was possible to partition the dissolved Zn among free and/or labile and strongly bound Zn fractions. In two natural waters, a high proportion (ca. 93-100%) of dissolved Zn was measured, and the residual ZnO particles were mainly composed of small agglomerates (average sizes ranging from 133.6 to 172.4 nm in the surface water and from 167.6 to 216.4 nm in the wastewater effluent). Small numbers of small nanoparticles were also detected in nonspiked waters.

Single Particle ICP-MS: Advances toward routine analysis of nanomaterials

“…To overcome this, Hadioui et al coupled ion exchange chromatography (IEC) prior to analysis by spICP-MS in order to remove signal from dissolved analyte [53,111]. For NPs that have shown a propensity to dissolve readily in environmental samples such as silver [112] and zinc oxide [113], IEC is used to greatly improve the resolution of nanoparticle signals from an elevated background signal emanating from dissolved analyte, thereby improving size detection limits.…”

Overcoming challenges in single particle inductively coupled plasma mass spectrometry measurement of silver nanoparticles

“…More commonly, an alternative method utilizing measured transport efficiency ( η n ) and analyte response in ionic standards is adopted [20]. It has greatly expanded the application of spICP-MS to a number of ENMs, including Ag [17, 18, 25, 28–34], Cu [35], TiO 2 [28], ZnO [36, 37], CeO 2 [37], and La 2 O 3 [38]. This approach relies on η n , which is determined experimentally via particle size, or frequency methods, using available NP standards (e.g., gold nanoparticle RM 8012 or RM 8013 from the National Institute of Standards and Technology (NIST)).…”

“…η n is one of the major factors influencing the accuracy of spICP-MS measurement for both particle size and concentration [22], but evaluation and comparison of η n determined by these two methods using certified RMs has been limited. Most studies applied the frequency method [17, 18, 25, 29, 32, 34, 35] and many did not specify how η n was determined [28, 36–38]. For example, in a single particle calculation tool published by RIKILT Wageningen University & Research [41], the transport efficiency calculation uses the frequency method alone.…”

Effect of preparing method of ZnO powders on electrical arc erosion behavior of Ag/ZnO electrical contact material

“…Short arcs occur during bouncing. 28 At break, it is well known that arcing takes place after contacts rupture and the metallic phase and gaseous phase occurs for arcs. [44][45][46][47] Figure 6 shows typical arc energy at breaking state.…”

“…[21][22][23][24][25][26][27] Zinc oxide with a diversity of well-defined morphologies has been synthesized by decomposing Zn(OH) 4 2À or Zn(NH 3 ) 4 21 conditions. [28][29][30][31][32][33] The flower-like, disk-like, and dumbbelllike ZnO microcrystals have been controllably achieved by a capping-molecule-assisted method. [34][35][36][37][38][39] Given the demand for a longer service life, many studies have been done for a better understanding of effects of the composition.…”