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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
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
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
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
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
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
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
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
Jeanita Pritchett, Katrice A. Lippa, Mary Bedner, Carolyn Q. Burdette, Johanna Camara, Brian E. Lang, Michael A. Nelson, Lane C. Sander, Lorna T. Sniegoski
The one week NIST-SIM chemical metrology training opportunity was designed to provide SIM NMI/DI laboratory personnel with in-depth classroom and hands-on laboratory experience for the implementation of isotope dilution/mass spectrometry (ID/MS) methods in
Melissa M. Phillips, Mary Bedner, Manuela Reitz, Carolyn Q. Burdette, Michael A. Nelson, James H. Yen, Lane C. Sander, Catherine A. Rimmer
Two independent analytical approaches, based on liquid chromatography with absorbance detection and liquid chromatography with mass spectrometric detection, have been developed for determination of isoflavones in soy materials. These two methods yield
Jorge O. Ona Ruales, Walter B. Wilson, Federica Nalin, Lane C. Sander, Patricia Schubert, Stephen A. Wise
A link between the aromatic character of polycyclic aromatic hydrocarbons (PAHs) and gas chromatography (GC) elution order in columns with a polysiloxane backbone in the stationary phase is reported for the first time. The aromatic character was calculated
Walter B. Wilson, Lane C. Sander, M. J. Lopez de Alda, Milton Lee, Stephen A. Wise
Retention indices for 79 alkyl-substituted polycyclic aromatic sulfur heterocycles (PASHs) were determined by using reversed-phase liquid chromatography (LC) on a monomeric and polymeric octadecylsilane (C18) stationary phase. Molecular shape parameters
Walter B. Wilson, Lane C. Sander, M. J. Lopez de Alda, Milton Lee, Stephen A. Wise
Retention indices for 70 polycyclic aromatic sulfur heterocycles (PASHs) were determined using reversed-phase liquid chromatography (LC) on a monomeric and a polymeric C18 stationary phase. Molecular shape parameters [length, breadth, thickness (T), and