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Latest:
Evaluation of Fatty Acids as Biochemical Markers for Source Identification of Indian OpiumThis method describes an attempt to identify the source of licit Indian opium based on the fatty acid profile. The analysis was based on gas chromatography (GC) with flame ionization (FID) and mass spectrometric detectors (MS). A total of 124 Indian opium samples were collected and fingerprinted for the presence of various fatty acids. Qualitative analysis of fatty acids indicated the acids such as behenic, stearic and lignoceric were significant biochemical markers, making it a useful method to identify the source of opium for forensic purposes.
Latest:
Evaluation of Fatty Acids as Biochemical Markers for Source Identification of Indian OpiumThis method describes an attempt to identify the source of licit Indian opium based on the fatty acid profile. The analysis was based on gas chromatography (GC) with flame ionization (FID) and mass spectrometric detectors (MS). A total of 124 Indian opium samples were collected and fingerprinted for the presence of various fatty acids. Qualitative analysis of fatty acids indicated the acids such as behenic, stearic and lignoceric were significant biochemical markers, making it a useful method to identify the source of opium for forensic purposes.
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Analytical Limbo: How Low Can You Go?September 2006. In analytical chemistry, the continual quest for enhanced sensitivity and specificity - in gas chromatography (GC), this can be equated to separation power - remain the common goal in the development of new analytical methodologies. Today, GC is still the most widely used method for the analysis of volatile and semivolatile organic compounds. When coupled with the right choice of detector for the specific application, a wide linearity range and low limit of detection (LOD) can be met. For GC analyses, many approaches can be used to achieve greater sensitivity and lower LOD. They can be classified broadly into four categories: improved sampling (sample preparation) strategies; sample introduction methods; improved chromatographic performance; and alternative (selective–sensitive) detection transducers. This article provides an up-to-date review of existing and emerging chromatographic innovations, based upon these four strategies, that will improve sensitivity and detection limits of trace..
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Simultaneous Determination of Positive and Negative Counterions Using a Hydrophilic Interaction Chromatography MethodThe 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.
Latest:
Evaluation of Fatty Acids as Biochemical Markers for Source Identification of Indian OpiumThis method describes an attempt to identify the source of licit Indian opium based on the fatty acid profile. The analysis was based on gas chromatography (GC) with flame ionization (FID) and mass spectrometric detectors (MS). A total of 124 Indian opium samples were collected and fingerprinted for the presence of various fatty acids. Qualitative analysis of fatty acids indicated the acids such as behenic, stearic and lignoceric were significant biochemical markers, making it a useful method to identify the source of opium for forensic purposes.
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Headspace Liquid MicroextractionA 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.
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In-Tube Solid-Phase Microextraction and On-Line Coupling with High-Resolution GCA 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.
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Applying Highly Selective Reaction Monitoring for the Assay of Midazolam and 1-Hydroxymidazolam in Plasma using LC-MS-MSMidazolam is a central nervous system depressant that is commonly used as a sedative before surgical or other medical procedures.
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Application of Novel Ethylene Bridged Hybrid Particles for Hydrophilic-Interaction ChromatographyUsing 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.
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Evaluation of Polar-Embedded and Polar-Endcapped C12-C18 Stationary Phase Vulnerabilities Toward Highly Nucleophilic Compounds: A Case StudyHere 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.
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The LCGC Awards: Opening DoorsThe 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.
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Stephen Dal Nogare: The Person Behind the AwardThe 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.
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Hydrophilic Interaction Capillary Electrochromatography for the Separation of Polar CompoundsThe authors introduce hydrophilic interaction capillary electrochromatography as a capillary column technique for the separation of polar compounds.
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Simultaneous Determination of Chelating Agents by Ion-Suppression and Ion-Pair Chromatography in WastewaterChelating 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.
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Chromatography Applications in Drug Discovery of Therapeutic ProteinsIn 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.
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How to Build a GLP Bioanalytical LabOctober 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.
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Micropipette Tip-Based Sample Preparation for BioanalysisThe 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.
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What Drives a Separation — the Stationary Phase or the Mobile Phase?The author investigates solute partitioning between the mobile and stationary phases to determine the driving force of reversed-phase liquid chromatography separations.
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Analysis of Volatile Bacterial Metabolites by Gas Chromatography–Mass SpectrometryA 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.
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Generic Capillary Electrochromatographic Screening and Optimization Strategies for Chiral Method DevelopmentThis 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.
Latest:
In-Tube Solid-Phase Microextraction and On-Line Coupling with High-Resolution GCA 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.
Latest:
Simultaneous Determination of Positive and Negative Counterions Using a Hydrophilic Interaction Chromatography MethodThe 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.
Latest:
Headspace Liquid MicroextractionA 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.
Latest:
Chromatography Fundamentals, Part X: Light Scattering Detection Systems for Size-Exclusion ChromatographyThis exploration into commercially available light scattering detection systems for size-exclusion chromatography (SEC) emphasizes new technologies and will help users understand the options.
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Single Calibrant Quantification with HPLC — Fact or Fantasy?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.
Latest:
Stephen Dal Nogare: The Person Behind the AwardThe 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.
Latest:
Prevention is Better Than Cure: An Alternative Approach in Sample Preparation of Complex SamplesCombining a membrane with a solid sorbent can improve selectivity and save time in sample preparation.
