A GC in Your Laptop

Author: Jaap de Zeeuw

Restek Corporation

Published By: The Analytical Scientist

Year of Publication: December 2018

Volume, Issue: Volume 71

Link: https://theanalyticalscientist.com/fileadmin/tas/pdf-versions/TAS_Issue_1218.pdf


Very few students get hands-on experience with a working gas chromatography system. In this article, Jaap de Zeeuw explains how we can overcome this problem using ProEZGC software. By simulating separations, this free, web-based software allows users to change any GC parameter and see how the separations are affected.


Analysis of d- and l-Amphetamine and Methamphetamine Enantiomers for High-Throughput Labs

Published By: Restek Corporation

Year of Publication: 2018

Link: https://www.restek.com/Development/cft_CFSS2974-UNV

Abstract: Accurate analysis of amphetamine and methamphetamine isomers can be achieved using chiral columns, but the method presented here provides a simpler, more cost-effective approach for high-throughput labs. Excellent separation of all isomers in urine was obtained in a fast, 7-min LC-MS/MS quantitative analysis on a Raptor C18 column with no interference from matrix components.

5.5 Minute LC-MS/MS Analysis of Mycotoxins in Peanut Powder

Published By: Restek Corporation

Year of Publication: 2018

Link: https://www.restek.com/Technical-Resources/Technical-Library/Foods-Flavors-Fragrances/fff_FFSS2971-UNV

Abstract:The method developed here provides a fast analysis of mycotoxins in peanut powder. Baseline separation of 12 FDA and EU regulated mycotoxins was achieved in a 5.5 minute analysis (7 minute total cycle time). This method can be applied to different matrices using either matrix-matched calibration or a stable isotope dilution assay. Sample throughput can be greatly increased by the short cycle time for each run.

Detailed Efficiency Analysis of Columns with a Different Packing Quality and Confirmation via Total Pore Blocking

Author: David S. Bell

Restek Corporation

Published By: Journal of Chromatography A

Year of Publication: December 2018

Volume, Issue:Volumes 1581–1582

Link: https://doi.org/10.1016/j.chroma.2018.10.052 


We report on a systematic study involving columns with a clearly different efficiency (4 distinct quality groups) obtained by packing the columns that were C18 bonded and end capped with a different carbon loading. Using B-term analysis (via peak parking) and theoretical models to estimate the magnitude of the Cm– and Cs-term contributions, it could be concluded that the difference in efficiency among the groups was entirely due to a difference in eddy dispersion. As such, the columns provided an ideal testing ground to verify how well the total pore blocking (TPB)-method can be used to probe differences in packing heterogeneity. In agreement with earlier literature observations, it turns out the TPB-method is much more sensitive to packing heterogeneities than the eddy dispersion (Heddy)-contribution measured under open-pore conditions via B- and C- term subtraction. Typically, differences in Heddy on the order of 0.1–0.5μm translate into a difference on the order of 0.5–2μm in the TPB mode. This confirms the TPB as a powerful technique to make very sensitive measurements of the homogeneity of packed beds.

Leveraging Selectivity and Efficiency to Take the Strain Out of LC–UV Method Development for Cannabinoid Profiling

Author(s): Justin Steimling
Restek Corporation

Published By: Cannabis Science and Technology

Issue: Volume 1, Issue 4

Year of Publication: 2018

Link: http://www.cannabissciencetech.com/article/leveraging-selectivity-and-efficiency-take-strain-out-lc%E2%80%93uv-method-development-cannabinoid

Abstract: More than 100 cannabinoids have been isolated from cannabis in addition to the five most commonly tested: ∆9-tetrahydrocannabinol (∆9-THC), ∆9-tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), and cannabinol (CBN). Although many methods have been published that show the separation of these major cannabinoids, most do not take into account the possibility of interference from minor cannabinoids. This interference is most problematic in concentrates where minor cannabinoids can be enriched to detectable levels. Additionally, some terpenes absorb ultraviolet (UV) light at the same wavelength as cannabinoids, which can result in an additional source of interference. In this study, the liquid chromatography (LC)–UV separation of 16 cannabinoids of interest was performed while the potential impact from minor cannabinoids and terpenes on reported potency values was monitored. The method was applied to commercially available CBD oils that have recently become suspect because of inaccurate label claims.

Liquid Chromatography: Pharmaceutical Applications (Chapter in Reference Module in Chemistry, Molecular Sciences and Chemical Engineering)

Author(s): D.M. Diehl1, David S. Bell2, Barbara Bojko3
1. Waters Corporation, 2. Restek Corporation, 3. Nicolaus Copernicus University

Published By: Elsevier

Year of Publication: 2018

Link: https://www.sciencedirect.com/science/article/pii/B9780124095472144920

Abstract: Liquid chromatography (LC) has been applied in the pharmaceutical industry almost from the inception of the technique. In this article, the overview of recent advancements in LC, like ultra-high-performance liquid chromatography and superficially porous particle (SPP) technology, which were adopted to analysis of pharmaceuticals can be found. The utilization of liquid chromatography during development and manufacturing stages of small molecule drugs is described. That includes aspects of purification, isolation, identification, and stability, among others. The article also considers application of modern LC strategies to analysis of the currently most emerging group of drugs, biopharmaceuticals. Finally, the LC approaches for metabolomics in drug discovery as well as pharmacometabolomics are discussed.

Comprehensive LC-MS/MS Analysis of 15 Bisphenols in 8 Minutes

Published By: Restek Corporation

Year of Publication: 2018

Link: http://www.restek.com/Technical-Resources/Technical-Library/Foods-Flavors-Fragrances/fff_FFSS2935-UNV

Abstract: The analysis of bisphenolic compounds that are used as alternatives to bisphenol A (BPA) is essential for monitoring exposure to and evaluating the safety of these emerging industrial chemicals. The LC-MS/MS method presented here provides excellent chromatographic peak shape and separation for an extensive list of BPA analogues in a fast, 8-minute analysis.

Fast, Simple LC-MS/MS Analysis of Creatine and Creatinine

Published By: Restek Corporation

Year of Publication: 2018

Link: http://www.restek.com/Technical-Resources/Technical-Library/Clinical-Forensic-Toxicology/cft_CFSS2937-UNV

Abstract: A rapid, robust method was established for the analysis of creatine and creatinine in human plasma and urine. An efficient separation was achieved in less than 1.5 min using a Raptor HILIC-Si column and a simple isocratic mobile phase.

When Do We Need Sub2m Superficially Porous Particles for Liquid Chromatography Separations

Author(s): David Bell, Landon Wiest, Shun-Hsin Liang, Dan Li
Restek Corporation

Published By: LCGC Asia Pacific

Issue: Volume 21, Issue 3

Year of Publication: 2018

Link: http://www.chromatographyonline.com/when-do-we-need-sub2m-superficially-porous-particles-liquid-chromatography-separations

Abstract: The use of superficially porous particles (SPPs) for modern high performance liquid chromatography (HPLC) is now very common. Initially, SPPs rose as an alternative to sub-2-µm fully porous particles (FPPs). In recent years, many column manufacturers have developed 2-µm and smaller SPP-based products. This article investigates the practical utility of these smaller SPP designs.

LC–MS Sensitivity: Practical Strategies to Boost Your Signal and Lower Your Noise

Author(s): Sharon Lupo
Restek Corporation

Published By: LCGC North America

Issue: Volume 36, Issue 9

Year of Publication: 2018

Link: http://files.pharmtech.com/alfresco_images/pharma/2018/09/20/34989658-b89e-46ca-9d30-f7577e2ef6c9/LCGC_NAmerica_Sept2018.pdf#page=14

Abstract: Liquid chromatography–mass spectrometry (LC–MS) has become the preferred analytical technique for many challenging assays based on its selectivity, sensitivity, and broad applicability to compounds of varying polarity. Despite the advantages of the technique, the complexity of LC–MS systems often leaves analysts struggling to meet method detection limits. In this installment of “Column Watch,” several strategies are discussed to improve method sensitivity through the reduction of contaminants, the careful selection of LC method conditions, and the optimization
of MS interface settings. By understanding the relationship between these parameters and ionization efficiency, analysts can enhance their signal-to-noise ratio and realize the hidden potential of the LC–MS technique.