Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry
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The Ohio State University / OhioLINK
2016
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=osu1471823411 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-osu14718234112021-12-20T05:37:19Z Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry Wilson, Austin T. Analytical Chemistry Chemistry Nanoscience ICP-MS nanoparticles sp-ICP-MS inductively coupled plasma mass spectrometry Growing use of engineered nanoparticles (NP) in consumer products, electronics, paints, fuels, food, supplements and medicine drives the need for analysis methods that can rapidly and accurately identify the NP composition, size, size distribution and number concentration. Single particle inductively coupled plasma mass spectrometry (sp-ICP-MS) has promise as such a method. Each nanoparticle is converted into a cloud (burst) of ions in the ICP that produces a 0.2 to ~ 1.5 ms wide signal. Calibration is required to relate the signal peak area to the mass of the NP (sensitivity) and the number of signal bursts detected to the number of NP/mL in the sample suspension (transport efficiency). However, questions remain regarding calibration methods and the accuracy and precision of the measured NP mean size, size distribution, and the number concentration. NP peak integration algorithms can end prematurely due to shot noise, resulting in erroneously low measured NP size. The sample matrix can affect the measured NP size and number concentration depending on calibration method used. When the signal produced from a NP is small (due to small NP size, low sensitivity or when measuring the edges of the ion cloud) shot noise can cause incomplete integration of the signal. Both the shape of the measured NP size distribution and the mean NP size can then be biased low. Using a modified peak detection algorithm, measured NP size distributions were similar to those measured from the same NP suspension with higher sensitivity (minimal impact of shot noise), consistent with complete NP signal peak integration. Standard NP suspensions and/or solutions are used to calibrate the transport efficiency and sensitivity (counts/fg into ICP). Some researchers reported that matrix matching the calibrants and NP sample resulted in the same measured NP size and number of particles per volume when NP or solution standards were used while others reported the opposite. The agreement between methods to measure transport efficiency varied among replicate NP suspensions and warrants further examination. When calibrants and NP samples were not matrix matched, the accuracy of the measured NP size and number concentration was degraded. When an internal standard (added to calibrants and NP samples) was used the measured NP size and number of NP/mL were more accurate. The presence of 1000 ppm Pb in a suspension of 55.8 nm Au NPs caused a 9 to 10x decrease in sensitivity and a 56% decrease in the number of NPs detected. Either both the transport efficiency and sensitivity decreased or the NP signals became too close to the detection limit. When 76.2 nm Au NPs were measured in 100 ppm Pb, the detected NP number concentration was similar to a NP suspension containing no added Pb but the measured size (69.8 nm) was biased low, consistent with a 36% decrease in sensitivity. These data suggest that either shot noise had a minimal effect on the signals from 76.2 nm Au NPs or 100 ppm Pb was not a high enough concentration to affect the transport efficiency. 2016 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1471823411 http://rave.ohiolink.edu/etdc/view?acc_num=osu1471823411 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
| collection |
NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Analytical Chemistry Chemistry Nanoscience ICP-MS nanoparticles sp-ICP-MS inductively coupled plasma mass spectrometry |
| spellingShingle |
Analytical Chemistry Chemistry Nanoscience ICP-MS nanoparticles sp-ICP-MS inductively coupled plasma mass spectrometry Wilson, Austin T. Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry |
| author |
Wilson, Austin T. |
| author_facet |
Wilson, Austin T. |
| author_sort |
Wilson, Austin T. |
| title |
Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry |
| title_short |
Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry |
| title_full |
Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry |
| title_fullStr |
Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry |
| title_full_unstemmed |
Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry |
| title_sort |
measurement of nanoparticle size distributions and number of nanoparticles per volume by inductively coupled plasma mass spectrometry |
| publisher |
The Ohio State University / OhioLINK |
| publishDate |
2016 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=osu1471823411 |
| work_keys_str_mv |
AT wilsonaustint measurementofnanoparticlesizedistributionsandnumberofnanoparticlespervolumebyinductivelycoupledplasmamassspectrometry |
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