부산대학교 도서관

In this work, the effects of using collision/reaction cell (CRC) technology in quadrupole-based ICP-MS (ICP-QMS) instrumentation operated in single-particle (SP) mode have been assessed. The influence of (i) various CRC gases, (ii) gas flow rates, (iii) nanoparticle (NP) sizes and (iv) NP types was evaluated using Ag, Au and Pt NPs with both a traditional ICP-QMS instrument and a tandem ICP-mass spectrometer. It has been shown that using CRC technology brings about a significant increase in the NP signal peak width (from 0.5 up to 6 ms). This effect is more prominent for a heavier gas (e.g. , NH 3) than for a lighter one (e.g. , H 2 or He). At a higher gas flow rate and/or for larger particle sizes >100 nm), the NP signal duration was prolonged to a larger extent. This effect of using CRC technology has been further demonstrated by characterizing custom-made 50 and 200 nm Fe 3 O 4 NPs (originally strongly affected by the occurrence of spectral overlap) using different CRC approaches (H 2 on-mass and NH 3 mass-shift). The use of NH 3 (monitoring of Fe as the Fe(NH 3) 2 + reaction product ion at m / z = 90 amu) induces a significant peak broadening compared to that observed when using H 2 (6.10 ± 1.60 vs. 0.94 ± 0.49 ms). This extension of transit time can most likely be attributed to the collisions/interactions of the ion cloud generated by a single NP event with the CRC gas and it even precludes 50 nm Fe 3 O 4 NPs to be detected when using the NH 3 mass-shift approach. Based on these results, the influence of a longer peak width on the accuracy of SP-ICP-MS measurement data (NP size, particle number density and mass concentration) must be taken into account when using CRC technology as a means to overcome spectral overlap. To mitigate the potential detrimental effect of using CRC technology in the characterization of NPs via SP-ICP-MS(/MS), the use of light gases and low gas flow rates is recommended. Image 1 • Pressurizing a collision/reaction cell extends nanoparticle transit time in SP-ICP-MS. • Type of gas and its flow rate influence the magnitude of the effect. • The effect is more pronounced for larger nanoparticles and also their morphology matters. • Extension of the transit time negatively affects SP-ICP-MS figures of merit. • Transit time extension can be exploited for monitoring >1 nuclide with scanning-type MS. [ABSTRACT FROM AUTHOR]