A variety of chromatographic sorbents are commercially available for reversed-phase liquid chromatography (RPLC) and while many of these columns are nominally similar, in practice the columns may provide significantly different separations.
Food quality differences are dependent on botanical and geographical origins of primary food ingredients as well as storage and handling. Quality assessment for food materials, including cocoa and olive oil, is demonstrated by applying two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass spectrometry (TOF-MS) and pattern recognition.
This article describes the method development and performance characteristics of the validated LFI assay and evaluates stability in human plasma.
Micellar liquid chromatography (MLC) is a reversed-phase liquid chromatographic mode with a solution of surfactant forming micelles as the mobile phase. The interaction of solutes with the stationary phase coated with surfactant monomers, combined with the increased solubilization capability of micelles, have profound implications with regard to retention, selectivity and efficiency. Practical steps that a chromatographer involved in MLC should consider when developing an analytical procedure are described, including mobile phase preparation, column conditioning and cleaning.
Corn stover is the above-ground portion of the plant minus the kernels and it accounts for a large percentage of the global supply of lignocelluosic biomass available as feedstock for fermentation systems used for biofuel production.
In the past decade, supercritical fluid chromatography (SFC) has been established as a cost-effective, sustainable, and green purification technology for pharmaceutical and related industries.
Semiquantitative elemental analysis by ICP-MS is a powerful tool for quick screening of unknown samples for a wide range of elements.
Amino Acids analysis method according to European Pharmacopoeia to support development and production of biopharmaceuticals.
The authors evaluate a method for detecting pesticide residues in dandelion root powder.
The 2013 Emerging Leader in Chromatography Award is granted to Davy Guillarme. Here we look at his career and accomplishments so far.
We explore the impact of two different stationary phases and ion-pair reagents on the retention behavior of a therapeutic peptide using reversed-phase liquid chromatography. This information is of fundamental importance for the development of reliable, selective, and fast analytical methods able to separate and identify the target peptide.
Helium is running out, the worldwide demand is exceeding current production levels. Learn how Hydrogen could be your perfect replacement for Helium.
Examples from food science illustrate the usefulness of chemometrics techniques like pattern recognition, regression, and classification.
A rapid LC–MS method using ESI coupled with SIM-MS for analysis of humulone and isohumulone content in beer is described.
Employing ion mobility at atmospheric pressure without vacuum enables coupling to high-resolution mass analyzers. High performance ion mobility–orbital trap mass spectrometry (HPIM-OT-MS) is a useful alternative for separating isomers, such as isomeric metabolites seen in drug discovery.
The authors investigated the two most popular types of interfaces for benchtop LC–MS systems – the particle interface and the atmospheric-pressure ionization interface – to learn how the information obtained separately from the two can be complementary.
In this edition of The LCGC Blog, André Striegel provides advice on how to prepare for your first talk or presentation at a scientific conference.
Understanding separation principles is the key to success. Here's why.
This month's "Directions in Discovery" gives a brief overview of turbulent- flow liquid chromatography, a technique for fast separations. Two examples demonstrate the use of the technology for high-throughput bioanalytical separations in drug discovery.
High performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) is a potential method of choice for the analysis of carbohydrates.
Biogen and Postnova present data on the analysis of adeno-associated viruses (AAV) using Asymmetrical Flow Field-Flow Fractionation coupled to Multi-Angle Light Scattering detection (AF4-MALS). AAV are promising gene therapy delivery vehicles, whose efficacy may be negatively affected by the presence of viral aggregates. Due to its gentle separation and broad applicable size range, AF4-MALS is able to characterize AAV and their aggregates with high resolution and precision, thereby overcoming the drawbacks that column-based chromatography techniques often face when dealing with samples larger than 50 nm in size.
Gas chromatography–mass spectrometry (GC–MS) with cold electron ionization (EI) is based on interfacing the GC and MS instruments with supersonic molecular beams (SMB) along with electron ionization of vibrationally cold sample compounds in SMB in a fly-through ion source (hence the name cold EI). GC–MS with cold EI improves all the central performance aspects of GC–MS. These aspects include enhanced molecular ions, improved sample identification, an extended range of compounds amenable for analysis, uniform response to all analytes, faster analysis, greater selectivity, and lower detection limits. In GC–MS with cold EI, the GC elution temperatures can be significantly lowered by reducing the column length and increasing the carrier gas flow rate. Furthermore, the injector temperature can be reduced using a high column flow rate, and sample degradation at the cold EI fly-through ion source is eliminated. Thus, a greater range of thermally labile and low volatility compounds can be analyzed. The extension of the range of compounds and applications amenable for analysis is the most important benefit of cold EI that bridges the gap with LC–MS. Several examples of GC–MS with cold EI applications are discussed including cannabinoids analysis, synthetic organic compounds analysis, and lipids in blood analysis for medical diagnostics.
This article highlights an advantage of porous graphitic carbon columns, that is their resistance at high temperatures, for the analysis of parabens in foodstuffs.
Headspace GC reveals that sonication can degrade common organic solvents.
Displacement chromatography is a viable alternative to elution chromatography, but the biotechnology industry has yet to fully exploit this technique. The authors present results of a pilot-scale ion-exchange displacement process developed for the removal of variants from recombitant human brain-derived neutrotrophic factor.
There are several key benefits to using multidimensional GC techniques in routine analysis. An examination of mineral oil analysis in food reveals the utility of these techniques.
Three-dimensional (3D) printing shows promise for creating stationary phases with tailored geometries. We present a method that overcomes limitations of other approaches, and can produce columns with a feature resolution of 10 μm.
An overview of different approaches for the qualitative and quantitative analysis of polysorbates.