Issue 9, 2014

Quantitative resolution of nanoparticle sizes using single particle inductively coupled plasma mass spectrometry with the K-means clustering algorithm

Abstract

Sensitive and accurate characterization of nanoparticle size in aqueous matrices at environmentally relevant concentrations is still challenging for current nano-analysis techniques. Single particle inductively coupled plasma mass spectrometry (spICP-MS) is an emerging method to characterize the size distribution of nanoparticles and determine their concentrations. Herein for the first time the K-means clustering algorithm is applied to signal processing of spICP-MS raw data. Compared with currently used data processing approaches, the K-means algorithm improved discrimination of particle signals from background signals and provides a sophisticated, statistically based method to quantitatively resolve different size groups contained within a nanoparticle suspension. In tests with commercial Au nanoparticles (AuNPs), spICP-MS with the K-means clustering algorithm can quantitatively discriminate secondary “impurity-size nanoparticles,” present at fractions of less than 2% by mass, from primary-size nanoparticles with the minimum resolvable size difference between the primary and secondary nanoparticles at ∼20 nm. AuNP mixtures in which 80 nm particles act as the “primary size group” and 20 nm, 50 nm, or 100 nm particles act as the “impurity size group” were analyzed by spICP-MS, which reliably measured percentages of secondary impurity-size nanoparticles that are consistent with the expected experimentally determined values. Compared with dynamic light scattering (DLS), spICP-MS has remarkably better particle size resolution capability. We also demonstrated the size measurement advantage of spICP-MS over DLS for commercial CeO2 nanoparticles that are commonly used in the semiconductor industry, where quality control of the nanoparticle size distribution is critical for the wafer polishing process.

Graphical abstract: Quantitative resolution of nanoparticle sizes using single particle inductively coupled plasma mass spectrometry with the K-means clustering algorithm

Supplementary files

Article information

Article type
Paper
Submitted
27 3 2014
Accepted
03 6 2014
First published
04 6 2014

J. Anal. At. Spectrom., 2014,29, 1630-1639

Quantitative resolution of nanoparticle sizes using single particle inductively coupled plasma mass spectrometry with the K-means clustering algorithm

X. Bi, S. Lee, J. F. Ranville, P. Sattigeri, A. Spanias, P. Herckes and P. Westerhoff, J. Anal. At. Spectrom., 2014, 29, 1630 DOI: 10.1039/C4JA00109E

To request permission to reproduce material from this article, 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 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