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Search Publications by: R. Michael Verkouteren (Fed)

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Displaying 1 - 25 of 35

Gravimetric deposition of microliter drops with radiometric confirmation

September 9, 2023
Author(s)
Denis E. Bergeron, Richard Essex, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren, Ryan P. Fitzgerald
A manual gravimetric dispensing technique is demonstrated using a micropipettor modified for use with removeable microcapillaries. Liquid scintillation sources were prepared from a well-characterized 241Am reference solution, providing a radiometric check

Isotope Dilution Mass Spectrometry as an Independent Assessment for Mass Measurements of Milligram Quantities of Aqueous Solution

January 1, 2023
Author(s)
Richard Essex, Jacqueline L. Mann, Denis E. Bergeron, Ryan P. Fitzgerald, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren
Isotope dilution mass spectrometry was used to independently assess the accuracy of mass measurement methods developed to quantitatively dispense milligram quantities of aqueous solution. Solutions of isotopically enriched 158Gd and enriched 155Gd were

Toward a New Primary Standardization of Radionuclide Massic Activity Using Microcalorimetry and Quantitative Milligram-Scale Samples

February 24, 2022
Author(s)
Ryan P. Fitzgerald, Bradley Alpert, Dan Becker, Denis E. Bergeron, Richard Essex, Kelsey Morgan, Svetlana Nour, Galen O'Neil, Dan Schmidt, Gordon A. Shaw, Daniel Swetz, R. Michael Verkouteren, Daikang Yan
We present a new paradigm for the primary standardization of radionuclide activity per mass of solution (Bq/g). Two key enabling capabilities are 4π decay-energy spectrometry using chip-scale sub-Kelvin microcalorimeters and direct realization of mass by

Sub-picoliter Traceability of Microdroplet Gravimetry and Microscopy

December 20, 2021
Author(s)
Lindsay C. C. Elliott, Adam L. Pintar, Craig R. Copeland, Thomas Brian Renegar, Ronald G. Dixson, Robert Ilic, R. Michael Verkouteren, Samuel M. Stavis
Volumetric analysis of single microdroplets is difficult to perform by ensemble gravimetry, whereas optical microscopy is often inaccurate beyond the resolution limit. To address the latter issue, we advance and integrate these complementary methods

Detection, counting and characterization of nanoplastics in marine bioindicators: a proof of principle study

April 15, 2021
Author(s)
Jeremie Parot, Andrea Valsesia, Jessica Ponti, Dora Mehn, Rita Marino, Daniela Melillo, Samantha Facchetti, Shinichiro Muramoto, R. Michael Verkouteren, Vincent A. Hackley, Pascal Colpo
Plastic particulates in the environment pose an increasing concern for regulatory bodies due to their potential risk to higher organisms (including humans) as they enter the food chain. Nanoplastics (pNP) (defined here as smaller than 1 µm) are

Discriminative potential of ion mobility spectrometry for the detection of fentanyl and fentanyl analogues relative to confounding environmental interferents

September 27, 2019
Author(s)
Thomas Forbes, Jeffrey Lawrence, Jennifer R. Verkouteren, R. Michael Verkouteren
The opioid crisis and emergence of fentanyl, fentanyl analogues, and other synthetic opioids has highlighted the need for sensitive and robust detection for interdiction at screening points, notably vehicles at border crossings and packages at postal

A Standards and Measurement Infrastructure for Calibration, Verification and Optimization of Trace Explosives Detection Systems

April 15, 2019
Author(s)
John G. Gillen, Jennifer R. Verkouteren, R M. Verkouteren, Marcela N. Najarro, Edward R. Sisco, Matthew E. Staymates, Jessica L. Staymates, Robert A. Fletcher, Jeffrey A. Lawrence, Elizabeth L. Robinson, Alexander T. Bulk, Joseph A. Bennett, Shinichiro Muramoto, Thomas P. Forbes
Current national priorities in homeland security have led to an unprecedented level of utilization of explosives trace detection (ETD) systems for counterterrorism and law enforcement. Despite the widespread deployment of ETD instruments at airports

ASTM E2677: Web-based International Standard on Limit of Detection for Explosive Trace Detectors (and More) - Opioids and Ozone

February 12, 2019
Author(s)
R M. Verkouteren, Nathanael A. Heckert, Stefan D. Leigh, Edward R. Sisco, James E. Norris, Jeffrey A. Lawrence, Amber Burns
The performance characteristics of explosive and narcotic trace detectors are mission-critical to agencies worldwide that are charged with protection of the public, defense for mass transit and infrastructure, and the safety of first responders. Commercial

Metrology for stable isotope reference materials: 13C/12C and 18O/16O isotope ratio value assignment of pure carbon dioxide gas samples on the Vienna PeeDee Belmnite-CO2 scale using dual-inlet mass spectrometry

May 25, 2018
Author(s)
Abneesh Srivastava, R M. Verkouteren
Isotope ratio measurements have been conducted on a series of isotopically distinct pure CO2 gas samples using the technique of dual-inlet isotope ratio mass spectrometry (DI-IRMS). The influence of instrumental parameters, data normalization schemes on

Metrology in Support of Trace Explosive Detection Equipment for Airport Security Applications.

October 16, 2008
Author(s)
George A. Klouda, J Greg Gillen, Robert A. Fletcher, E S. Etz, Jennifer R. Verkouteren, R. Michael Verkouteren, E Ferguson
We are working in collaboration with the Transportation Security Agency's Trace Explosive Detection Group to build a chemical metrology program to help support the widespread operational deployment and effective utilization of trace explosives detection

NIST Program to Support Testing and Evaluation of Trace Explosive Detection

October 1, 2007
Author(s)
R M. Verkouteren, John G. Gillen, Jennifer R. Verkouteren, Robert A. Fletcher, Eric S. Windsor, Wayne Smith
Trace detection is a primary strategy for thwarting terrorism activities in the US and abroad. The development of effective reference materials and methods for this purpose relies on fundamental knowledge regarding the size, mass, morphologies, and

Inkjet Metrology and Standards for Ion Mobility Spectrometry

September 1, 2007
Author(s)
R M. Verkouteren, J Brazin, Eric S. Windsor, Robert A. Fletcher, R Maditz, Wayne Smith, John G. Gillen
Piezoelectric inkjet nozzles offer precise control for dispensing small quantities of materials. NIST is developing inkjet metrology to provide reference materials, calibration services, and other standards for the IMS detection of trace contraband

Piezoelectric Trace Vapor Calibrator

August 1, 2006
Author(s)
R M. Verkouteren, John G. Gillen, David Taylor
The design and performance of a vapor generator for calibration and testing of trace chemical sensors are described. The device utilizes piezoelectric nozzles to dispense and vaporize precisely known amounts of analytic solutions onto a hot ceramic surface

Consistency of D 13 C Measurements Improved

February 1, 2006
Author(s)
T B. Copelen, W Brand, M Gehre, M Groening, HAJ Meijer, Blaza Toman, R. Michael Verkouteren
We present state-of-the-art measurements and data evaluation methods to show that the consistency of carbon isotope ratio measurements can be improved 39 % to 47 % by anchoring the measurement scale with two isotopic reference materials differing in carbon

IMS-Based Trace Explosives Detectors for First Responder Use

September 1, 2005
Author(s)
Jennifer R. Verkouteren, John G. Gillen, R M. Verkouteren, Robert A. Fletcher, E S. Etz, George A. Klouda, Alim A. Fatah, Philip J. Mattson
The purpose of this document is to establish minimum performance requirements and an associated test method for Ion Mobility Spectrometry (IMS) based trace explosives detectors for use by the first responder community. Information concerning the theory and

Standardization of Isotope Ratio Measurements for Doping Control

December 1, 2004
Author(s)
R M. Verkouteren
Pharmaceutical steroids are known to differ in isotopic composition from those produced naturally in the body. By measuring the 13 C/ 12C ratio of specific steroids deteched in urine, the technique of Gas Chromatography-Combustion-Isotope Ratio Mass