An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Susan Tai, Michael Nelson, Brian Lang, Karen W. Phinney, Lane C. Sander, James H. Yen, J. M. Betz, Christopher T. Sempos, Stephen Wise
The National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Health, Office of Dietary Supplements (NIH-ODS) and the Vitamin D Standardization Program (VDSP), has recently issued a new serum-matrix Standard
Brian Lang, Aaron A. Urbas, Paul C. DeRose, Hung-Kung Liu, John C. Travis, Steven J. Choquette, Kenneth D. Cole
New spectrophotometers and cuvettes have been designed to allow the measurement of absorbance values from samples using microliter volume sizes. These measurements are done using short pathlengths to decrease the sample volumes required. The major
Critical dimension atomic force microscopy (CD-AFM) is a measurement technique that uses flared tips and two-dimensional surface sensing to enable scanning of features with near-vertical sidewalls. A major source of uncertainty in metrology with CD-AFM is
Walter Wilson, Hugh Hayes, Lane Sander, Andres Campiglia, Stephen Wise
A normal-phase liquid chromatography (NPLC) fractionation procedure was developed for the characterization of a complex mixture of polycyclic aromatic hydrocarbons (PAHs) from a coal tar sample (Standard Reference Material (SRM) 1597a). Using a semi
Since 2004 standards for calibration of CD-AFM tip width have been available both commercially and through national metrology institutes (NMIs) such as the National Institute of Standards and Technology (NIST) in the United States. There have been inter
The magnetic suspension mass comparator is a unique system for calibrating kilogram artifacts between vacuum and air. While the MSMC allows for direct vacuum-to-air mass measurements, there are several corrections that need to be accounted. Here, we
Marcus H. Mendenhall, Albert Henins, Lawrence T. Hudson, Csilla I. Szabo-Foster, Donald A. Windover, James P. Cline
The structure of the x-ray emission lines of the Cu Kα complex has been remeasured on a newly commissioned instrument, in a manner directly traceable to the Système Internationale definition of the meter. In this measurement, the region from 8000 to 8100
Chemical measurement methods are designed to promote accurate knowledge of a measurand or system and, as such, often allow elicitation of latent sources of variability and correlation in experimental data. They typically implement measurement equations
Karen W. Phinney, Susan S. Tai, Mary Bedner, Johanna Camara, Rosalind R. Chia, Lane C. Sander, Katherine E. Sharpless, Stephen A. Wise, James H. Yen, Rosemary L. Schleicher, Madhulika Chaudhary-Webb, Khin L. Maw, Yasamin Rahmani, Hubert W. Vesper, Joseph M. Betz, Joyce Merkel, Christopher T. Sempos, Paul M. Coates, Ramon Durazo-Arvizu, Kurtis Sarafin, Stephen P. Brooks
Andrew J. Allen, Fan Zhang, Regis J. Kline, William F. Guthrie, Jan Ilavsky
The certification of a new standard reference material for small-angle scattering: NIST Standard Reference Material (SRM) 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering (SAXS), based on glassy carbon is presented. Creation
Electrical scanning probe microscopes (eSPMs), such as the scanning Kelvin force microscope (SKFM), scanning capacitance microscope (SCM), or various scanning microwave microscopes (SMMs) are sensitive to the electric field between the sample and tip
Werickson Fortunato de Carvalho Rocha, Michele M. Schantz, David Sheen, Katrice Lippa, Pamela M. Chu
As feedstocks transition from conventional oil to increasing amounts of unconventional petroleum sources and biomass, it will be necessary to determine whether a particular fuel or fuel blend is suitable for use in engines. Certifying a fuel as safe for
A combination of cold neutron prompt gamma-ray activation analysis (CNPGAA) and thermal neutron (TN) PGAA was used to determine sulfur in fuel oils down to 0.1 % for the purpose of developing a method to provide values for certification. The cold neutron
Christian Wuethrich, Hitoshi Akimichi, Mercede Bergoglio, James A. Fedchak, Karl Jousten, Sueng Soo Hong, Jorge T. Guzman
The comparison CCM.M.P-K14 is a key comparison in pressure involving six laboratories in three regional metrological organizations (RMO). The measurand of the comparison is the accommodation coefficient of two spinning rotating gauge characterized in
To address community needs, the National Institute of Standards and Technology (NIST) has developed a candidate Standard Reference Material (SRM) for infant/adult nutritional formula based on milk and whey protein concentrates with isolated soy protein
Robert A. Fletcher, Nicholas W. Ritchie, David S. Bright, James J. Filliben, William F. Guthrie
A new material has been certified to become Standard Reference Material (SRM) 2806b - Medium Test Dust in Hydraulic Fluid. SRM 2806b consists of a trace polydisperse, irregularly shaped mineral dust particles suspended in hydraulic fluid. The certified
Stephen E. Long, Stephen A. Wilson, Stuart J. Nagourney
The quality assurance of analytical data generated for environmental materials is critical to State and Federal regulatory agencies to ensure that decisions based upon the amounts of contaminants in environmental samples are truly protective of public
A preliminary interlaboratory study (ILS) was conducted in Aug-Sep of 2016, in order to evaluate the capacity of widely used optical-based commercial measurement platforms to yield a common value for zeta potential (ZP) using a single well-characterized
Justin M. Zook, Marc L. Salit, Lisa V. Kalman, Mickey Williams, Vivekananda Datta, Jin-Yeong Han
Characterized reference materials (RM) are needed for test development and validation, quality control procedures and proficiency testing to assure the quality of clinical laboratory tests. In this article, we review the development and characterization of
This report of analysis documents procedures used to obtain certified values and associated uncertainties of the density of iso-octane SRM 2214 over an extended range of temperatures and pressures. This SRM is certified over the temperature range 50˚C to
Ndubuisi G. Orji, Ronald G. Dixson, Domingo I. Garcia-Gutierrez, Bunday Benjamin, M R. Bishop, Michael W. Cresswell, Richard A. Allen, John Allgair
One of the key challenges in critical dimension (CD) metrology is finding suitable dimensional calibration standards. The transmission electron microscope (TEM), which produces lattice-resolved images having scale traceability to the SI (International
The magnetic suspension mass comparator at NIST is a fully automated mass comparator with the unique feature that it is able to directly compare a mass in vacuum to one in air. The technique is realized by coupling a weighing pan located in air to a mass
The National Institute of Standards and Technology (NIST), at the request of the National Institute of Healths (NIHs) Office of Dietary Supplements (ODS) and in conjunction with the Centers for Disease Control and Prevention (CDC), initiated a third
Kelly H. Telu, Xinjian Yan, William E. Wallace, Stephen Stein, Yamil Simon
Non-targeted global metabolite profiles of Standard Reference Material 1950, "Metabolites in Human Plasma," were obtained on five different liquid chromatography/mass spectrometry (LC/MS) instrument combinations using identically prepared samples
Nanoparticles (NPs) are widely used in diverse application areas, such as medicine, engineering, and cosmetics. The size (or volume) of NPs is one of the most important parameters for their successful application. It is relatively straightforward to