A new sampling method for gas chromatography termed single-drop microextraction (SDME) is described. In this column, SDME is applied to residual solvent analysis, both in manual and automated modes.
A novel device for coupling on-line in-tube SPME with capillary GC is presented by the guest authors and the method's application demonstrated for the analysis of contaminants in water.
Midazolam is a central nervous system depressant that is commonly used as a sedative before surgical or other medical procedures.
Using HILIC with highly efficient ethylene bridged hybrid (BEH) particles results in faster methods that exhibit improved polar retention, higher sensitivity, enhanced chromatographic resolution and significantly improved column lifetime.
Here the authors discuss an ion-pair, gradient HPLC method, developed for cycloserine-related substances using a polar, amide-embedded C18 column. Other polar-embedded and polar-edcapped columns are evaluated in equivalence studies.
The LCGC Awards have now been in existence since 2008, and with several years of award winners now active in the chromatography community, it is fair to say that we now have a reasonable track record and body of work to review in measuring the impact these awards have had, both on the industry and on the winners themselves.
The Stephen Dal Nogare award is one of the oldest and most prestigious awards given in chromatography. Little has been written about Stephen Dal Nogare "the man" or his contributions to scientific knowledge, including his unique contributions to separations science. This article describes his scientific career and how it has influenced the practice of chromatography.
The authors introduce hydrophilic interaction capillary electrochromatography as a capillary column technique for the separation of polar compounds.
Chelating agents such as NTA, CDTA and DTPA are considered by ANDRA (the French national agency for radioactive waste management) as compounds to be investigated because they may enhance the release of radioactive isotopes in the environment.
In this month's installment of "Directions in Discovery," the authors discuss how, with the arrival of combinatorial libraries and high-throughput screening, pharmaceutical firms can develop new models of drug discovery that not only lessen the initial capital outlay involved in drug discovery, but also refine the discovery process.
October 2006. This month's "MS - The Practical Art" will interest those starting a new good laboratory practices (GLP) bioanalytical laboratory, reassessing an existing lab, or revamping a "spirit-of-GLP" laboratory to full GLP status.
The micropipette tip containing solid phases is a relatively new sample preparation format that permits the handling of microlitre and submicrolitre amounts of liquid samples using the techniques of solid-phase extraction, dialysis and enzyme digestion. Phases are packed, embedded or coated on the walls of the pipette, permitting liquid samples to be moved and transferred without undue pressure drop or plugging. This column reviews the latest technologies in micropipette tip sample preparation used in the study of genomics, proteomics and metabolomics.
The author investigates solute partitioning between the mobile and stationary phases to determine the driving force of reversed-phase liquid chromatography separations.
A method for the identification of key volatile organic compound (VOC) markers associated with infection by Neisseria meningitidis bacteria by gas chromatography–mass spectrometry (GC–MS) was developed. Headspace samples of bacterial VOCs were trapped on triple-sorbent bed tubes and then thermally desorbed into a laboratory GC–MS system for separation. Identification was carried out by comparison of GC retention time and electron ionization mass spectra to the National Institute of Standards and Technology (NIST) database. Further confirmation was obtained by GC–MS of known standard chemicals. A total of 75 VOCs were detected, five of which can be considered key VOC markers for Neisseria meningitidis. These peaks were identified as 1,2-dimethylcyclopropane, 2-methylpropanal, methacrolein, N-2-dimethyl-1-propanamine, and 3-methylbutanal by the NIST database.
This article presents an overview of the work performed to define generic separation strategies and methods in chiral method development using capillary electrochromatography as a separation technique. Polysaccharide chiral stationary phases were found suitable for this purpose. Two separate strategies were defined, one for acidic and one for non-acidic substances. These strategies were evaluated and found applicable on structurally diverse molecules, showing their generic character.
A novel device for coupling on-line in-tube SPME with capillary GC is presented by the guest authors and the method's application demonstrated for the analysis of contaminants in water.
The authors work to develop a universal high performance liquid chromatography method that is capable of simultaneously retaining and separating both cations and anions within a single chromatographic analysis for the purpose of quantification in pharmaceutical products.
A new sampling method for gas chromatography termed single-drop microextraction (SDME) is described. In this column, SDME is applied to residual solvent analysis, both in manual and automated modes.
This exploration into commercially available light scattering detection systems for size-exclusion chromatography (SEC) emphasizes new technologies and will help users understand the options.
This article assesses the extent to which some familiar HPLC detectors can provide reliable quantitative analytical measurements when no suitable primary reference standard exists. The advantages and limitations of two candidate detector schemes are discussed ? evaporative light-scattering detection (ELSD) and chemiluminescent nitrogen detection (CLND). It was found that when the ERETIC (Electronic REference To access In-vivo Concentrations) method in proton NMR was used as a "gold standard" reference procedure the ability of CLND to provide reliable single calibrant quantification is superior to ELSD. Furthermore, ELSD showed bias towards underestimation of chromatographically-resolved impurities, resulting in an overestimation of analyte purity.
The Stephen Dal Nogare award is one of the oldest and most prestigious awards given in chromatography. Little has been written about Stephen Dal Nogare "the man" or his contributions to scientific knowledge, including his unique contributions to separations science. This article describes his scientific career and how it has influenced the practice of chromatography.
Combining a membrane with a solid sorbent can improve selectivity and save time in sample preparation.
October 2006. This month's "MS - The Practical Art" will interest those starting a new good laboratory practices (GLP) bioanalytical laboratory, reassessing an existing lab, or revamping a "spirit-of-GLP" laboratory to full GLP status.
Salt formation is a critical aspect in drug development and HPLC is an important tool for determination of pharmaceutical counterions.
In January 2004, LCGC Europe published an article on methods for selecting pure gases for analytical applications. 1 Here, the authors expand on this topic by addressing questions regarding gas mixtures - defined simply as more than one gas in a cylinder.
Is it possible to combine a serious scientific meeting together with social events and fun? Well if it is possible then the ExTech and HTC-9 meeting held in York, UK between 6?10 February came very close.
A method for the identification of key volatile organic compound (VOC) markers associated with infection by Neisseria meningitidis bacteria by gas chromatography–mass spectrometry (GC–MS) was developed. Headspace samples of bacterial VOCs were trapped on triple-sorbent bed tubes and then thermally desorbed into a laboratory GC–MS system for separation. Identification was carried out by comparison of GC retention time and electron ionization mass spectra to the National Institute of Standards and Technology (NIST) database. Further confirmation was obtained by GC–MS of known standard chemicals. A total of 75 VOCs were detected, five of which can be considered key VOC markers for Neisseria meningitidis. These peaks were identified as 1,2-dimethylcyclopropane, 2-methylpropanal, methacrolein, N-2-dimethyl-1-propanamine, and 3-methylbutanal by the NIST database.