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Search Publications by: Karen E. Murphy (Assoc)

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Displaying 1 - 25 of 54

Versailles Project on Advanced Materials and Standards (VAMAS) Interlaboratory Study on Measuring the Number Concentration of colloidal gold nanoparticles

March 9, 2022
Author(s)
Caterina Minelli, Karen E. Murphy, Monique Johnson, Antonio Montoro Bustos, Jeffrey Fagan, Ingo Strenge
We describe the outcome of an international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced

Certification of Standard Reference Material(R) 2386 Avocado Powder

October 20, 2021
Author(s)
Melissa M. Phillips, Laura J. Wood, George Caceres, Grace Hahm, Karen E. Murphy, Rick L. Paul, Benjamin Place, James H. Yen
The National Institute of Standards and Technology (NIST) recently released SRM 2386 Avocado Powder which has value assignment for over 70 analytes. This material has certified values assigned for 22 analytes and non-certified values assigned for 53

Certification of Standard Reference Material(R) 955d, Toxic Elements and Metabolites in Frozen Human Blood

October 15, 2020
Author(s)
Lee L. Yu, Karen E. Murphy, Colleen E. Bryan Sallee, Thomas W. Vetter, Robert C. Hagwood, George C. Caceres, Stephen E. Long, J M. Jarrett, M A. Franklin, J Castro Georgi, D M. Jones, Robert Jones, Z Li, Y L. Sommer, D S. Tevis, K Wallon, C D. Ward, M Maras, S Erdahl, C Gilmer, M Wermers, H Woldeysus, K F. Mehigan, M Morrissette, Christopher D. Palmer, Patrick J. Parsons
Standard Reference Material (SRM) 955d is intended for use in validating analytical methods for measuring toxic elements and mercury species in human blood, and in value assigning locally produced control materials analyzed using the validated methods. A

Determining what really counts: Modeling and measuring nanoparticle number concentrations

August 1, 2019
Author(s)
Elijah J. Petersen, Antonio R. Montoro Bustos, Blaza Toman, Monique E. Johnson, Mark Ellefson, George C. Caceres, Anna Lena Neuer, Qilin Chan, Jonathan Kemling, Brian Mader, Karen E. Murphy, Matthias Roesslein
Elijah J. Petersen, Antonio Montoro Bustos, Blaza Toman, Monique Johnson, Mark Ellefson, George C. Caceres, Anna Lena Neuer, Qilin Chan, Jonathan Kemling, Brian Mader, Karen Murphy, Matthias Roesslein

Validation of Single Particle ICP-MS for Routine Measurements of Nanoparticle Size and Number Size Distribution

November 25, 2018
Author(s)
Antonio R. Montoro Bustos, Premsagar P. Kavuri, Antonio M. Possolo, Natalia Farkas, Andras Vladar, Karen E. Murphy, Michael R. Winchester
Single particle inductively coupled plasma-mass spectrometry (spICP-MS) is an emerging technique capable of measuring nanoparticle size and number concentration simultaneously, of metal-containing nanoparticles (NPs) at environmentally relevant levels

Development of a kelp powder (Thallus laminariae) Standard Reference Material

December 9, 2017
Author(s)
Lee L. Yu, Joseph Browning, Carolyn Q. Burdette, George C. Caceres, Kaitlyn Chieh, William C. Davis, MIchael Ellisor, Brittany Kassim, Stephen E. Long, Karen E. Murphy, Rabia Oflaz, Rick L. Paul, Katherine E. Sharpless, Laura J. Wood, James H. Yen, Rolf L. Zeisler
A Standard Reference Material (SRM) of seaweed, SRM 3232 Kelp Powder (Thallus laminariae) has been developed to support food and dietary supplement measurements in compliance with the Food Safety Modernization Act (FSMA) and the Dietary Supplement Health

Sucrose density gradient centrifugation for efficient separation of engineered nanoparticles from a model organism, Caenorhabditis elegans

October 11, 2017
Author(s)
Monique E. Johnson, Antonio R. Montoro Bustos, Elijah J. Petersen, Shannon K. Hanna, Karen E. Murphy, Lee L. Yu, Bryant C. Nelson, Michael R. Winchester
This protocol describes a strategy for separating Caenorhabditis elegans (C. elegans) from engineered nanomaterials, a critical step for accurate quantification in uptake studies. Conventional rinsing procedures, typically comprised of water or buffer

NanoUV-VIS: an interactive visualization tool for monitoring the evolution of optical properties of nanoparticles throughout synthesis reactions

September 20, 2017
Author(s)
Bryan Calderon Jimenez, Gabriel Sarmanho, Karen E. Murphy, Antonio R. Montoro Bustos, Jose R. Vega Baudrit
Engineered nanoparticles (NPs) are being used for a broad array of high technology applications including sensing, imaging, targeted drug delivery, bio-diagnostics, catalysis, optoelectronics and film growth seeding. The enhanced optical, electrical and

Analytical Methods and Development of Reference Materials for Toxic Metals and Metal Species in Food and Dietary Supplements

September 18, 2017
Author(s)
Stephen E. Long, Michael B. Ellisor, Frances Nilsen, Laura J. Wood, Karen E. Murphy, Lee L. Yu
Highly toxic metals such as arsenic, cadmium, lead and mercury are prevalent in the terrestrial and marine environments from both natural sources and anthropogenic activities. Contamination of food can often occur during agricultural production and food

Quantitative characterization of gold nanoparticles by size-exclusion and hydrodynamic chromatography, coupled to inductively coupled plasma mass spectrometry and quasi-elastic light scattering

July 14, 2017
Author(s)
Leena M. Pitkanen, Antonio Montoro Bustos, Karen E. Murphy, Michael R. Winchester, Andre Striegel
The physicochemical characterization of nanoparticles, in general, and of gold nanoparticles (Au NPs), in particular, is of paramount importance for tailoring and optimizing the properties of these materials in specific applications, as well as for

Silver nanoparticles: technological advances, societal impacts, and metrological challenges

February 21, 2017
Author(s)
Bryan Calderon Jimenez, Monique E. Johnson, Antonio R. Montoro Bustos, Karen E. Murphy, Michael R. Winchester, Jose R. Vega Baudrit
Silver nanoparticles (AgNPs) show different physical and chemical properties compared to their macroscale analogs. This is primarily due to their small size and, consequently, the exceptional surface area of these materials. Presently, advances in the

Separation, Sizing, and Quantitation of Engineered Nanoparticles in an Organism Model Using Inductively Coupled Plasma Mass Spectrometry and Image Analysis

December 16, 2016
Author(s)
Monique E. Johnson, Shannon Hanna, Antonio R. Montoro Bustos, Christopher M. Sims, Lindsay C. Elliott, Babak Nikoobakht, John T. Elliott, Richard D. Holbrook, Keana C. Scott, Karen E. Murphy, Elijah J. Petersen, Lee L. Yu, Bryant C. Nelson, Akshay Lingayat, Adrian C. Johnston
For environmental studies assessing uptake of orally ingested engineered nanoparticles (ENPs), a key step in ensuring accurate quantification of ingested ENPs is efficient separation of the organism from ENPs that are either nonspecifically adsorbed to the

Certification Report for the Reference Materials ERM-AE142 and ERM-EB400 A pure Pb solution and a bronze material, both certified for their Pb isotope amount ratios

July 1, 2016
Author(s)
Jochen Vogl, Dorit Becker, Maren Koenig, Yong-Hyeon Yim, Kyoung-Seok Lee, Heidi Goenaga-Infante, Dmitriy Malinowskiy, Sarah Hill, Tongxiang Ren, Jun Wang, Robert D. Vocke Jr., Karen E. Murphy, Naoko Nonose, Olaf Rienitz, Janine Noordmann
Lead isotope analysis is often applied in various fields such as archaeology, geochemistry and forensic science. Despite this, only the 3 primary isotopic reference materials NIST SRM; 981, NIST SRM 982 and NIST SRM 983 are available, whereby NIST SRM 981

Development of Two Fine Particulate Matter Standard Reference Materials (

April 13, 2016
Author(s)
Michele M. Schantz, Danielle Cleveland, N. Alan Heckert, John Kucklick, Stefan D. Leigh, Stephen E. Long, Jennifer Lynch, Karen E. Murphy, Rabia Oflaz, Adam L. Pintar, Barbara J. Porter, Savelas A. Rabb, Stacy Schuur, Stephen Wise, Rolf L. Zeisler
Two new Standard Reference Materials (SRMs), SRM 2786 Fine Particulate Matter (

Preparation of silver nanoparticle loaded cotton threads to facilitate measurement development for textile applications

January 26, 2015
Author(s)
Justin M. Gorham, Karen E. Murphy, Jingyu Liu, Dimitri Tselenchuk, Gheorghe NMN Stan, Thao M. Nguyen, Richard D. Holbrook, Michael R. Winchester, Robert F. Cook, Robert MacCuspie, Vincent A. Hackley
FOREWORD This NIST special publication (SP) is one in a series of NIST SPs that address research needs articulated in the National Nanotechnology Initiative (NNI) Environmental, Health, and Safety Research Strategy published in 2011 [1]. This Strategy

Final report of the key comparison CCQM-K98: Pb isotope amount ratios in bronze

July 1, 2014
Author(s)
Jochen Vogl, Yong-Hyeon Yim, Kyoung-Seok Lee, Heidi Goenaga-Infante, Dmitriy Malinowskiy, Tongxiang Ren, Jun Wang, Robert D. Vocke Jr., Karen E. Murphy, Naoko Nonose, Olaf Rienitz, Janine Noordmann, Teemu Naeykki, Timo Sara-Aho, Bet?l Ari, Oktay Cankur
Isotope amount ratios are proving useful in an ever increasing array of applications that range from studies unravelling transport processes, to pinpointing the provenance of specific samples as well as trace element quantification by using isotope

Use of Single Particle Inductively Coupled Plasma Mass Spectrometry to Characterize a New Silver Nanoparticle Reference Material

June 11, 2014
Author(s)
Karen E. Murphy, Jingyu Liu, William F. Guthrie, Justin M. Gorham, John E. Bonevich, Andrew J. Allen, Michael R. Winchester, Vincent A. Hackley, Robert MacCuspie
In this study we use inductively coupled plasma mass spectrometry operated in single particle mode (spICP-MS) to simultaneously characterize the size distribution and dissolved silver fraction of a new silver nanoparticle (AgNP) candidate reference

Certification of Total Arsenic in Blood and Urine Standard Reference Materials by Radiochemical Neutron Activation Analysis and Inductively Coupled Plasma Mass Spectrometry

March 1, 2014
Author(s)
Rick L. Paul, William C. Davis, Karen E. Murphy, Colleen E. Bryan Sallee, Lee L. Yu, William F. Guthrie, Dennis D. Leber, Thomas W. Vetter
A newly developed procedure for determination of arsenic by radiochemical neutron activation analysis was used to measure arsenic in SRM 955c Toxic Elements in Caprine Blood and SRM 2668 Toxic Elements in Frozen Human Urine for the purpose of providing

Capabilities of Single Particle Inductively Coupled Plasma Mass Spectrometry for the Size Measurement of Nanoparticles: A Case Study on Gold Nanoparticles

February 28, 2014
Author(s)
Jingyu Liu, Karen E. Murphy, Robert I. MacCuspie, Michael R. Winchester
The increasing application of engineered nanomaterials in consumer and medical products has motivated the development of single particle inductively coupled plasma mass spectrometry (spICP-MS) for characterizing nanomaterials under realistic environmental

Development of a Standard Reference Material for Metabolomics Research

November 4, 2013
Author(s)
Karen W. Phinney, Guillaume Ballihaut, Mary Bedner, Johanna Camara, Steven J. Christopher, William C. Davis, Nathan G. Dodder, Brian E. Lang, Stephen E. Long, Mark S. Lowenthal, Elizabeth A. McGaw, Karen E. Murphy, Bryant C. Nelson, Jocelyn L. Prendergast, Jessica L. Reiner, Catherine A. Rimmer, Lane C. Sander, Michele M. Schantz, Katherine E. Sharpless, Lorna T. Sniegoski, Susan S. Tai, Jeanice M. Brown Thomas, Thomas W. Vetter, Michael J. Welch, Stephen A. Wise, Laura J. Wood, William F. Guthrie, Robert C. Hagwood, Stefan D. Leigh, James H. Yen, Nien F. Zhang, Madhu Chaurhary-Webb, Huiping Chen, Bridgette Haynes, Donna J. LaVoie, Leslie F. McCoy, Shahzad S. Momin, Neelima Paladugula, Elizabeth C. Pendergrast, Christine M. Pfeiffer, Carissa D. Powers, Zia Fazili-Qari, Daniel Rabinowitz, Michael E. Rybak, Rosemary L. Schleicher, Mary Xu, Mindy Zhang, Arthur L. Castle, Brandi S. Benford, Gauthier Eppe

Dietary Supplement Laboratory Quality Assurance Program: Exercise I Final Report

August 7, 2013
Author(s)
Melissa M. Phillips, Catherine A. Rimmer, Laura J. Wood, Karen E. Murphy, Katherine E. Sharpless, Thomas W. Vetter
The NIST Dietary Supplement Laboratory Quality Assurance Program (DSQAP) was established in collaboration with the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) in 2007 to enable members of the dietary supplements community to