Issue 1, 2021

Improving detection capability for single particle inductively coupled plasma mass spectrometry with microdroplet sample introduction

Abstract

Single particle inductively coupled plasma mass spectrometry (sp-ICPMS) is an attractive technique for fast measurement of elemental composition, mass and particle number concentration (PNC) of metal containing nanoparticles (NPs). In order to investigate NPs <10 nm using ICPMS, low instrumental background and high detection efficiency are primary requirements. This study evaluated the performance of a sector-field ICPMS with standard and enhanced sensitivity (“Jet”) vacuum interfaces with different sample introduction setups: conventional pneumatic nebulization with (DSN) and without aerosol desolvation (PN) and microdroplet generation (MDG). Additionally, the influence of nitrogen gas as an addition to a dry aerosol was studied. In this study, transport efficiencies (TEs) and detection efficiencies (DEs) are determined for the different instrumental setups. Gold NP suspensions were analysed and evaluated for PNC and size. Applying counting statistics, the size limit of detection (LODsize) of gold nanoparticles (Au NPs) was estimated to be 6.1 nm and 4.7 nm for PN and MDG with the standard interface, and 3.6 nm and 3.1 nm for DSN and MDG with the “Jet” interface and nitrogen addition, respectively. Additionally, DEs for various elements were determined. 11 isotopes (27Al, 47Ti, 63Cu, 107Ag, 111Cd, 115In, 133Cs, 140Ce, 193Ir, 197Au, and 238U) were measured at a mass resolving power (MRP) of 300 while an MRP of 4000 was used for 56Fe and 66Zn. DEs obtained for the conventional nebulization system with a spray chamber (PN) were in the range of 10−4 to 10−2 counts per atom (low resolution) and 10−6 to 10−5 counts per atom (medium resolution), while significant improvement in DE was obtained for the MDG setup with the “Jet” interface and nitrogen addition resulting in the range of 10−2 to 10−1 counts per atom (low resolution) and 10−4 to 10−3 counts per atom (medium resolution). The enhancement in DE was most pronounced for isotopes of lower m/z indicating reduced mass discrimination of the “Jet” interface with nitrogen gas added to the sample aerosol. The corresponding LODSIZE could thus be decreased by 10 or 2 times for example for Al- and Au-containing NPs, respectively. At the same time the use of an MDG for sample introduction allowed for 98.5% TE in the analyses of NP suspensions, while a TE of 10% (PN) or 23% (DSN) was obtained with pneumatic nebulizers.

Graphical abstract: Improving detection capability for single particle inductively coupled plasma mass spectrometry with microdroplet sample introduction

Supplementary files

Article information

Article type
Paper
Submitted
30 Sep 2020
Accepted
23 Nov 2020
First published
26 Nov 2020
This article is Open Access
Creative Commons BY-NC license

J. Anal. At. Spectrom., 2021,36, 233-242

Improving detection capability for single particle inductively coupled plasma mass spectrometry with microdroplet sample introduction

J. Kocic, D. Günther and B. Hattendorf, J. Anal. At. Spectrom., 2021, 36, 233 DOI: 10.1039/D0JA00421A

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements