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Displaying 14851 - 14875 of 73922

Plumbing for Liquid Chromatography

January 12, 2017
Author(s)
Lane C. Sander
The setup and maintenance of liquid chromatographic equipment requires a basic knowledge of chromatographic hardware. Tubing connections are an essential component in liquid chromatography instrumentation. System function and performance depend on the

Preparation of Calibration Solutions

January 12, 2017
Author(s)
Lane C. Sander, Michele M. Schantz
Calibration solutions provide the basis for quantitation for most instrumental techniques. The instrumental responses for analytes in calibrants of known composition are compared with corresponding responses in samples to provide quantitation of the

Pressurized Fluid Extraction

January 12, 2017
Author(s)
Lane C. Sander
Pressurized fluid extraction (PFE) is one of several sample preparation methods that can be used to extract targeted analytes from a sample matrix into a solvent, to permit subsequent analysis. With PFE, samples are extracted with solvent in a pressurized

Principles of Quantitation: Chromatography

January 12, 2017
Author(s)
Lane C. Sander
The accurate characterization of the chemical composition of a sample depends on a variety of factors that must be considered by the analyst. Knowledge of how different approaches to quantitation affect the measurement accuracy is requisite to the

Sample Concentration and Processing

January 12, 2017
Author(s)
Lane C. Sander
Sample Concentration and Processing Sample concentration is a common step in sample preparation prior to analysis that is performed to increase method sensitivity or to exchange solvent environment. Sample concentration can be thought of as a separation

Sorting carbon nanotubes

January 12, 2017
Author(s)
Ming Zheng
Sorting of single-wall carbon nanotubes by their electronic and atomic structures in liquid phases is reviewed in this chapter. We first introduce the sorting problem, then provide an overview of several sorting methodologies, following roughly the

Soxhlet Extractions

January 12, 2017
Author(s)
Lane C. Sander
Soxhlet extraction is one of several sample preparation methods that can be used to transfer targeted analytes from a sample matrix into a solvent, to permit subsequent analysis. With Soxhlet extraction, samples are repeatedly extracted with solvent

Tricritical Point of the f-Electron Antiferromagnet USb 2 Driven by High Magnetic Fields

January 12, 2017
Author(s)
Ryan L. Stillwell, I Lin NMN Liu, N. Harrison, M. Jaime, J. R. Jeffries, Nicholas Butch
In pulsed magnetic fields up to 65T and at temperatures below the Neel transition, our magnetization and magnetostriction measurements reveal a field-induced metamagnetic-like transition that is suggestive of an antiferromagnetic to polarized paramagnetic

Troubleshooting Liquid Chromatographic Instrumentation and Methods

January 12, 2017
Author(s)
Lane C. Sander
The ability to assess analytical performance is a fundamental component of measurement science. Ultimately, measurement quality depends on the proper function of instrumentation in combination with appropriate methods. Evidence of proper function is

Use of Analytical Balances

January 12, 2017
Author(s)
Lane C. Sander
The determination of mass is a fundamental component in quantitative analysis, and weighing accuracy is an important factor for most applications. This presentation will highlight the use of different types of analytical balances and will demonstrate

Volumetric Transfer of Liquids

January 12, 2017
Author(s)
Lane C. Sander
Although volumetric measurements are usually less accurate than gravimetric based measurements, volumetric measurements are still in common use due to the convenience, and often higher throughput, that may be afforded by automatic pipettes. Analysts should

What is Chromatography All About?

January 12, 2017
Author(s)
Lane C. Sander
Chromatography is an example of a process by which a mixture is separated into at least two fractions with different compositions. Other separation methods exist, such as distillation, recrystallization, and extraction. Chromatography is used to analyze

Dietary Supplement Laboratory Quality Assurance Program: Exercise G Final Report

January 11, 2017
Author(s)
Kate Rimmer, Laura J. Wood, Melissa M. Phillips
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

Fast Formation of Low-Defect-Density Tethered Bilayers by Fusion of Multilamellar Vesicles

January 10, 2017
Author(s)
Tadas Ragaliauskas, Mindaugas Mickevicius, Bozena Rakovska, Tadas Penkauskas, Frank Heinrich, Gintaras Valincius
Multilamelar vesicles fuse to molecular-anchor-grafted surfaces yielding low defect density, tethered bilayer membranes. Continuous bilayers are formed within 10 min, while the electrically insulating bilayers with less than 0,1 υmu-1} defect density can

Gapped Excitation in Dense Kondo Lattice CePtZn

January 10, 2017
Author(s)
Leland Weldon Harriger, Steven M.T. Disseler, J. Gunasekera, Jose A. Rodriguez, J. Pixley, P. Manfrinetti, S. K. Dhar, D. K. Singh
We report on neutron υSR scattering studies of dense Kondo lattice CePtZn. The system develops long range incommensurate magnetic order as the temperature is reduced below T N = 1.75 K. Interesting, a Q-indpenedent characteristic and its persistence to

LipidPioneer: Comprehensive User-Generated Exact Mass Templates for Lipidomics

January 10, 2017
Author(s)
Candice Z. Ulmer, John Bowden, Jared M. Ragland, Timothy J. Garrett, Jeremy P. Koelmel
Lipidomics, the comprehensive measurement of lipid species in a biological system, has promising potential in biomarker discovery and elucidating disease etiology. Advances in separation, mass spectrometric techniques, and applications to novel substrates

Retention behavior of alkyl-substituted polycyclic aromatic sulfur heterocycle isomers in gas chromatography on stationary phases of different selectivity

January 10, 2017
Author(s)
Walter B. Wilson, Lane C. Sander, Jorge O. Ona Ruales, Stephanie Mossner, Leonard M. Sidisky, Milton Lee, Stephen A. Wise
Retention indices for 10 sets of alkyl-substituted polycyclic aromatic sulfur heterocycles (PASHs) isomers (total of 80 PASHs) were determined using gas chromatography with three different stationary phases: a 50% phenyl phase, a 50% liquid crystalline

Retention behavior of isomeric polycyclic aromatic sulfur heterocycles in gas chromatography on stationary phases of different selectivity

January 10, 2017
Author(s)
Walter B. Wilson, Lane C. Sander, Jorge O. Ona Ruales, Leonard M. Sidisky, Milton Lee, Stephen A. Wise
Retention indices for 70 polycyclic aromatic sulfur heterocycles (PASHs) were determined using gas chromatography with three different stationary phases: a 50% phenyl phase, a 50% liquid crystalline dimethylpolysiloxane (LC-DMPS) phase, and an ionic liquid

Coherent UV-to-Visible Light Arrays

January 9, 2017
Author(s)
Dong Yoon Oh, Scott Diddams, Ki Youl Yang, Kerry J. Vahala, Connor Fredrick, Gabriel Ycas
Short duration, intense pulses of light can experience dramatic spectral broadening when propagating through lengths of optical fiber. This continuum generation process is caused by a combination of nonlinear optical effects including the formation of so

Origins and Demonstrations of Electrons with Orbital Angular Momentum

January 9, 2017
Author(s)
Benjamin McMorran, Amit Agrawal, Peter Ercius, Vincenzo Grillo, Andrew Herzing, Tyler R. Harvey, Martin Linck
The surprising message of the 1992 paper of Allen, Beijersbergen, Spreeuw, and Woerdman (ABSW) was that photons could exhibit orbital motion in free space, which subsequently launched advancements in optical manipulation, microscopy, quantum optics

Preflight Radiometric Calibration of Orbiting Carbon Observatory 2

January 9, 2017
Author(s)
Stephen Maxwell, B. Carol Johnson, Robert Rosenberg, Lars Chapsky, Richard A. Lee, Randy Pollock
This paper describes the prelaunch radiometric calibration of the imaging spectrometers used on the second Orbiting Carbon Observatory (OCO-2). The gain and dark response were characterized for each focal plane array detector element. An integrating sphere
Displaying 14851 - 14875 of 73922
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