U.S. flag

An official website of the United States government

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.

Search Publications

NIST Authors in Bold

Displaying 51 - 75 of 2062

Characterizing Styrene Monomer and Oligomers by SEC/MALS/VISC/DRI

January 10, 2024
Author(s)
Andre Striegel
Worldwide polystyrene (PS) production in 2020 was approximately 27 million metric tons, distributed among many nations, making it one of the most heavily imported and exported chemicals. Commercially produced PS usually possesses a broad molar mass

Determination of D9-THC, THCA, D8-THC, and total D9-THC in 53 Smokable Hemp Plant Products by Liquid Chromatography and Photodiode Array Detection

January 8, 2024
Author(s)
Walter Brent Wilson, Aaron Urbas, MARYAM ABDUL-RAHMAN, Arianna Romares, Ewelina Mistek-Morabito
The passage of the 2018 Farm Bill has led to an estimated value of $824M for hemp production in the United States (US) in 2021 with an approximately 76% of it focused on floral hemp that is used to produce hemp-derived finished products such as smokable

Recommendations from the Ocean Carbonate System Intercomparison Forum: Quantifying and reducing uncertainties in the calculations of carbonate system equilibrium in the oceans

December 14, 2023
Author(s)
Brendan Carter, Jonathan Sharp, Andrew Dickson, Marta Alvarez, Michael Fong, Maribel Garcia-Ibanez, Ryan Woosley, Takeshita Yuichiro, Leticia Barbero, Robert Byrne, Wei-Jun Cai, Melissa Chierici, Simon Clegg, Regina Easley, Andrea Fassbender, Kalla Fleger, Xinyu Li, Macarena Martin-Mayor, Katelyn Schockman, Aleck Wang Zhaohui
The ocean carbonate system is critical to monitor because it plays a major role in regulating Earth's climate and marine ecosystems. It is monitored using a variety of measurements, and it is commonly understood that all major components of the seawater

Best practices in NMR metabolomics: Current state

December 12, 2023
Author(s)
Tracey Schock, Amanda Bayless, Goncalo Gouveia, Robert Powers, Valerie Copie, John Cort, Hamid R. Eghbalnia, Wimal Pathmasiri, David S Wishart, Erik Andersson, Robert Brua, Leo Cheng, Chaevien Clendinen, Darcy Cochran, Alexandra Crook, Michah Jeppesen, Amith Maroli, Matthew Merritt, Heidi Roth, Isin Sakallioglu, Saurav Sarma, Lloyd Sumner, Panteleimon Takis, Mario Uchimiya
A literature survey was conducted to identify current practices used by NMR metabolomics investigators. A total of 463 papers from 2020 and 80 papers from 2010 were selected from PubMed. The papers were manually analyzed by a team of investigators to

Current practices in LC-MS untargeted metabolomics: a scoping review on the use of pooled quality control samples

December 6, 2023
Author(s)
Clay Davis, Corey Broeckling, Richard Beger, Cheng Leo, Raquel Cumeras, Daniel Cuthbertson, Surendra Dasari, Warwick Dunn, Anne Evans, Alvaro Fernandez-Ochoa, Kelli Goodman, Helen Gika, Roy Goodacre, Jennifer Kirwan, Kodra Dritan, Julia Kuligowski, Maria Monge, Jonathan Mosley, Sindhu Nair, Nichole Reisdorph, Stacy Sherrod, Georgios Theodoridis, Candice Ulmer Holland, Dajana Vuckovic, Bo Zhang, Goncalo Gouveia
Untargeted metabolomics is an analytical approach with numerous applications, serving as an effective metabolic phenotyping platform to characterize the small molecules within a biological system. Data quality can be challenging to evaluate and demonstrate

Untargeted metabolomics analyses and contaminant chemistry of Dreissenid mussels at the Maumee River Area of Concern in the Great Lakes

November 22, 2023
Author(s)
Tracey Schock, Daniel Bearden, Fabio Casu, Michael Edwards, Annie Jacob, Edward Johnson, Amanda Bayless, Elena Legrand
Bivalves stand out as an ideal ecological indicator and have been the basis of NOAA's Mussel Watch Program to monitor environmental health. In this study, we aimed to investigate the health of the Dreissenid mussel in the Maumee River. In addition to the

Metabolomics 2022 Workshop Report: State of QA/QC Best Practices in LC-MS-Based Untargeted Metabolomics, Informed Through mQACC Community Engagement Initiatives

November 8, 2023
Author(s)
Tracey Schock, Warwick Dunn, Julia Kuligowski, Jonathan Mosley, Candice Ulmer Holland, Dajana Vuckovic
Introduction: The Metabolomics Quality Assurance and Quality Control Consortium (mQACC) organized a workshop during the Metabolomics 2022 conference. Objectives: The goal of the workshop was to disseminate recent findings from mQACC community-engagement

Recommendations for setting a criterion and assessing commutability of sample materials used in external quality assessment/proficiency testing schemes

November 2, 2023
Author(s)
Sverre Sandberg, Pernille Fauskanger, Jesper Johansen, Thomas Keller, Jeffrey Budd, Neil Greenberg, robert rej, MAURO PANTEGHINI, VINCENT DELATOUR, Ferruccio Ceriotti, Liesbet Deprez, Johanna Camara, Finlay MacKenzie, Alicia Lyle, Eline van der Hagen, Chris Burns, W. Greg Miller
It is important for external quality assessment materials (EQAMs) to be commutable with clinical samples; i.e., they should behave like clinical samples when measured using end-user clinical laboratory in vitro diagnostic medical devices (IVD-MDs). Using

Single-Detector Double-Beam Modulation for High-Sensitivity Infrared Spectroscopy

October 25, 2023
Author(s)
Seongmin Kim, Yow-Ren Chang, Young Jong Lee
Balanced detection based on double beams is widely used to reduce common-mode noises, such as laser intensity fluctuation and irregular wavelength scanning, in absorption spectroscopy. However, employing an additional detector can increase the total system

Host Defense Peptide Piscidin and Yeast-derived Glycolipid Exhibit Synergistic Antimicrobial Action through Concerted Interactions with Membranes

October 19, 2023
Author(s)
Fei Liu, Alexander Greenwood, Yawei Xiong, Rebecca Miceli, Riqiang Fu, Kyle Anderson, Scott McCallum, Ella Mihailescu, Richard Gross, Myriam Cotten
Developing new antimicrobials as alternatives to conventional antibiotics has become an urgent race to eradicate drug-resistant bacteria and save human lives. Conventionally, antimicrobial molecules are studied independently even though they can be co

CCQM_Retrospectoscope Reference Manual: A detailed reference to the CCQM_Retrospectoscope, a suite of graphical tools for the meta-analysis of measurement results from CCQM studies

September 12, 2023
Author(s)
David L. Duewer, Michael Nelson, Christina Cecelski
The CCQM_Retrospectoscope system combines a nominally complete database of results from Consultative Committee for the Amount of Substance: Metrology in Chemistry and Biology (CCQM) studies with a number of graphical tools for trying to make sense of the

Target and Suspect Screening Integrated with Machine Learning to Discover Per- and Polyfluoroalkyl Substance Source Fingerprints

September 11, 2023
Author(s)
Nayantara Joseph, Trever Schwichtenberg, Dunping Cao, Gerrad Jones, Alix Rodowa, Joe Charbonnet, Christopher Higgins, Damian Helbling, Jennifer Field
This study elucidates per- and polyfluoroalkyl substance (PFAS) fingerprints for specific PFAS source types. Ninety-two samples were collected from aqueous film-forming foam impacted groundwater (AFFF-GW), landfill leachate, biosolids leachate, municipal

Inferring the nominal molecular mass of an analyte from its electron ionization mass spectrum

August 23, 2023
Author(s)
Arun Moorthy, Anthony J. Kearsley, William Mallard, William E. Wallace, Stephen E. Stein
The performance of three algorithms for predicting nominal molecular mass from an analyte's electron ionization mass spectrum is presented. The Peak Interpretation Method (PIM) attempts to quantify the likelihood that a molecular ion peak is contained in

Mid-Infrared, Near-Infrared, and Visible Nanospectroscopy of Hydrogen-Intercalated MoO3

August 21, 2023
Author(s)
Jeffrey Schwartz, Sergiy Krylyuk, Devon Jakob, Albert Davydov, Andrea Centrone
Control over the local chemical composition and spatial heterogeneities in nanomaterials provides a means to impart new functions and to tailor their properties in many applications. For two-dimensional (2D) van der Waals materials, intercalation is one

Rapid chemical screening of microplastics and nanoplastics by thermal desorption and pyrolysis mass spectrometry with unsupervised fuzzy clustering

August 11, 2023
Author(s)
Thomas P. Forbes, John Pettibone, Eric S. Windsor, Joseph M. Conny, Robert A. Fletcher
The transport and chemical identification of microplastics and nanoplastics (MNPs) are critical to the concerns over plastic accumulation in the environment. Chemically and physically transient MNP species present unique challenges for isolation and

Recommendations for Setting a Criterion for Assessing Commutability of Secondary Calibrator Certified Reference Materials

August 11, 2023
Author(s)
W. Greg Miller, Thomas Keller, Jeffrey Budd, Jesper Johansen, Mauro Panteghini, Neil Greenberg, Vincent Delatour, Ferruccio Ceriotti, Robert Rej, Johanna Camara, Liesbet Deprez, Finlay MacKenzie, Alicia Lyle, Eline van der Hagen, Chris Burns, Pernille Fauskanger, Sverre Sandberg
A secondary higher-order calibrator is required to be commutable with clinical samples to be suitable for use in the calibration hierarchy of an end-user clinical laboratory in vitro diagnostic medical device (IVD-MD). Commutability is a property of a

Engineering Nanopore Approaches toward Protein Sequencing

July 25, 2023
Author(s)
Xiaojun Wei, Tadas Penkauskas, Joseph Reiner, Mark Uline, Qian Wang, Sheng Li, Aleksei Aksimentiev, Joseph Robertson, Chang Liu
Biotechnological innovations have vastly improved the capacity to perform large-scale protein studies, while the methods we have of identifying and quantifying individual proteins are still inadequate to perform protein sequencing at the single-molecule

On the challenge of unambiguous identification of fentanyl analogs: exploring measurement diversity using standard reference mass spectral libraries

July 11, 2023
Author(s)
Arun Moorthy, Edward Erisman, Anthony J. Kearsley, Yuxue Liang, Edward Sisco, William E. Wallace
Fentanyl analogs are a class of designer drugs that are particularly challenging to unambiguously identify due to the mass spectral and retention time similarities of unique compounds. In this paper, we use agglomerative hierarchical clustering to explore
Displaying 51 - 75 of 2062