An optimization strategy to obtain the best possible performance in the shortest analysis time for comprehensive off-line 2D-LC.
A fast and simple sample preparation method for the simultaneous determination of 11 phytohormones in plants by GC–MS has been developed.
Analysis time can be reduced 10–30% by switching from constant-flow-rate mode to a constant-pressure gradient-elution mode.
Recent advances in sampling techniques in the pharmaceutical industry sparked significant interest in applying improvements to extraction methods for greater analyte detection and quantitation.
Military jet fuel (JP-8) is very similar to commercial jet fuel (Jet A) except for the presence of three additives, fuel system icing inhibitor, corrosion inhibitor–lubricity improver (CI-LI), and antistatic additive, which are added to improve characteristics of JP-8.
An improved LC–MS/MS method that can rapidly detect fipronil, an insecticide harmful to human health, is presented here for chicken eggs, feed, and soil.
This article examines the problem of dermorphin doping in horse racing and presents an effective method for its detection using LC–MS TQ.
This article discusses the novel legal highs that appear on the market and how forensic laboratories work to keep ahead of the game.
This month's guest authors review the application of solid-phase microextraction (SPME) to the analysis of drugs in human plasma discussing important factors in the optimization of extraction efficiency. The column concludes with a discussion of method validation issues.
Chiral separation screening has become a widely accepted approach for the rapid identification of an appropriate chiral stationary phase for use in more focused enantioseparation optimization. A set of extended screens encompassing various chromatographic modes using HPLC and SFC is presented.
Canola largely contains unsaturated fatty acids, thus rendering it clear in most cases after extraction and refining.
A new method to optimize liquid chromatography (LC) methods using a Quality by Design (QbD) approach is presented. This method is based on the use of design of experiments (DOE) and independent component analysis (ICA) to accurately estimate the modeled responses (that is, the retention times at the beginning, the apex, and the end) of each peak, even for coeluted peaks. This method was applied to the optimization of the separation of nine compounds in a mixture, yielding the design space and the demonstration of robustness of the method.
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.
An application of MALDI-MS in qualitative and quantitative analysis of pharmaceutical compounds spiked in urine is demonstrated.
A fast, sensitive and accurate quantitative method was developed using HPLC–MS–MS for analysis of phthalate metabolites in urine samples.
Systematic toxicological analysis is an important step in medicolegal investigations of death, poisoning, and drug use. The primary goal is the detection and confirmation of potentially toxic compounds in evidence. This article describes a workflow using nontargeted liquid chromatography–tandem mass spectrometry (LC–MS/MS) for reliable compound identification.
This article presents a method that combines combustion digestion and ion chromatography into a single analysis (combustion ion chromatography [CIC]) making it possible to detect halogens and sulphur in complex matrices. The method is suitable for use in a wide range of application areas.
This application note demonstrates how the use of DCM in particular had a dramatic effect on the separation and afforded conditions that could be further adapted to a preparative scale application.
For the next improvements, we must look beyond the column.
In reversed-phase liquid chromatography (LC), C18 alkyl-based stationary phases have been the favourite of method developers. Phenyl stationary phases are an alternative that are thought to benefit from additional π-π mechanisms. Recently, there has been a growing interest in the use of phases based on the biphenyl moiety. This instalment of “Column Watch” looks at the retention mechanisms of biphenyl phases and contrasts them with those of more-common alkyl phases.
Biotherapeutics must endure in-depth testing to validate their efficacy and safety before their release to the medical community. Characterization and quantitation of these large molecule medicines is traditionally performed with ligand binding assays or radiolabeling procedures. Issues with selectivity, accuracy, and unavailability of applicable assays for the characterization and quantitation of certain biotherapeutics means that liquid chromatography–mass spectrometry (LC–MS) is becoming an increasingly selected method for biotherapeutics testing. Typically used for small molecules, LC–MS can be adapted for larger molecule analysis with additional high throughput and multiplexing capabilities. New method development has turned LC–MS into a highly sensitive option for biotherapeutics validation.
The pyrolysis–GC–MS method enables direct analysis of solid or liquid polymers without sample pretreatment, as illustrated here for various materials, including a dental filling material and a car wrapping foil.