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An important prerequisite of a good sampling procedure for skin sebum is its reproducibility.

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By taking advantage of the benefits provided by normal-phase mode, highly productive and cost-effective strategies for high-throughput purification of drug discovery products have been developed in the analytical laboratories at Lilly-Spain. The straightforward scaling-up of generic protocols from an analytical to a preparative scale has yielded successful results not only when working in HPLC but also when transferring conditions to other standard low and medium pressure chromatographic systems that are routinely used by synthetic chemists.

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Protein unfolding and aggregation can be serious considerations when designing laboratory and preparative chromatographic purification steps. This problem has been studied most thoroughly within the contexts of reversed-phase chromatography and hydrophobic interaction chromatography. However, there are currently no robust methods for resin selection capable of predicting adsorbed-phase protein stability as a function of amino acid sequence, secondary or tertiary structure, or resin characteristics.

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This article focuses on the initial development of an LC–MS method to screen for cyanotoxins at low parts-per-billion levels.

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An exploration of LDTD-MS-MS and how it compares to HPLC–MS-MS techniques in terms of sensitivity, robustness, and speed in an in-vivo drug discovery application

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The authors show how several factors can contribute to a chromatogram's appearance.

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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.

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This installment of "Sample Prep Perspectives" discusses microdialysis sampling and the opportunities and challenges it presents. The guest authors look at microdialysis theory and equipment and describe potential applications...

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An important prerequisite of a good sampling procedure for skin sebum is its reproducibility.

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This 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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This article reports the application of the SPE-chiral ligand-exchange chromatography technique to monitor D-lactic acid formation during the alcoholic fermentation of white grape must.

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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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This article reports the application of the SPE-chiral ligand-exchange chromatography technique to monitor D-lactic acid formation during the alcoholic fermentation of white grape must.

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This article describes the use of a 96-well, solvent-resistant filtration plate for total drug analysis in blood plasma.

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Online monitoring of odour and taste components that occur at parts-per-trillion (ppt) levels in industrial process waters requires specialized analytical hardware that is generally not compatible with the harsh environmental conditions in these typical industrial settings. An alternative instrumental method is proposed that uses dynamic extraction in combination with gas chromatography (GC) equipped with a simple flame ionization detector (FID) to achieve these extremely low detection limits.

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It would help to have a restricted set of chromatographic systems (CS) that together serve as potential starting points in method development.

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Gerard Rozing highlights the importance of the HPLC 2023 Best Poster Award (BPA).

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This article describes a software solution for automating the chromatographic method validation process starting from experimental planning, data acquisition and processing, through final report generation in a seamless manner. All experimental planning and calculations are accomplished within the chromatography data software and, thus, are structurally validated, secure, and audit trailed. Highlights of the software are provided, including benefits to the analyst. The analysis of important method validation characteristics such as linearity, accuracy, and precision is automated. These characteristics and their acceptance criteria can be captured in a method template, which adheres to the company's standard operating procedure. This template method can then be used repeatedly by other scientists in the organization, hence, eliminating the need to create a new experimental plan each time a new validation is conducted.

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Demonstrating the suitability of a new wax stationary phase for GCxGC analysis of essential oils

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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.

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This 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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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.

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The authors describe a system for automated analytical temperature-rising elution fractionation that uses the built-in differential refractometer of a commercial gel-permeation chromatography instrument and a stop-flow method for sample crystallization.

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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.

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There is growing evidence that blueberries have powerful disease-fighting properties. Here the authors explore the research being done in this area, describing the use of a magnetic seector GC-MS SIM method to determine the presence of phenolic antioxidants in blueberries.

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In a good laboratory practice (GLP) environment, data-handling software cannot be used until it is validated. This even applies to the most simple program that performs calculations or stores data. A detailed documentation of the set-up and the performance of the software - called software validation - is required. The development and validation requirements are described in this article and illustrated with a software for robustness testing (SRT), which guides the user step-by-step through the experimental set-up and interpretation of robustness tests. This software was developed in an Excel (Windows XP) environment and is used as part of method validation in laboratories that require compliance with GLP and 21 CFR Part 11. The software was subjected to software validation regulations and is compliant with electronic records and signature rules (21 CFR Part 11) as it creates, delivers and stores electronic data. The validation tests are based on the computerized system validation (CSV) -..

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The established kinetic plots clearly show that monolithic columns are suited for large plate number separations whereas in the small plate number range the 3 ?m packed bed system is to be preferred.