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Post hoc Interlaboratory Comparison of Single Particle ICP-MS Size Measurements of NIST Gold Nanoparticle Reference Materials



Antonio R. Montoro Bustos, Elijah J. Petersen, Antonio M. Possolo, Michael R. Winchester


Single particle inductively coupled plasma-mass spectrometry (spICP-MS) is an emerging technique that enables simultaneous measurement of nanoparticle size and number quantification of metal-containing nanoparticles at realistic environmental exposure concentrations. These measurements are critical to accurately understand the potential environmental and human health risks of nanoparticles. However, some important limitations still remain and spICP-MS cannot yet be considered a mature methodology. Additional work is needed to standardize this technique including an assessment of the reliability and variability of size distribution measurements and the transferability of the technique among laboratories. This paper presents the first post hoc interlaboratory comparison study of spICP-MS technique using measurement results for two NIST gold nanoparticles reference materials (RMs 8012 and 8013) provided by six expert laboratories. Evaluation of spICP-MS precision indicates substantial variability among laboratories, and lower variability between operators within laboratories. The general agreement in particle size between spICP-MS and six reference techniques demonstrates the reliability of spICP-MS and validates its sizing capability. However, the precision of the reference techniques and spICP-MS was better for the larger 60 nm gold nanoparticles. Statistical analysis did not suggest an optimal dwell time, because this parameter does not significantly affect either the measured mean particle size or to the ability to count NPs. Finally, the spICP-MS data was often best fit with several single non-Gaussian distributions or mixtures of Gaussian distributions. Models other than the frequently used normal or lognormal distribution typically fit the data the best.
Analytical Chemistry


single particle ICP-MS, Nanoparticles, Interlaboratoy comparison, Nanomaterial Environmental Health and Safety


Montoro, A. , Petersen, E. , Possolo, A. and Winchester, M. (2015), Post hoc Interlaboratory Comparison of Single Particle ICP-MS Size Measurements of NIST Gold Nanoparticle Reference Materials, Analytical Chemistry, [online], (Accessed June 19, 2024)


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Created August 12, 2015, Updated March 13, 2017