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Size exclusion chromatography (SEC) coupled to light-scattering, viscometer and refractive index detectors is a common technique used for the characterization of polymers. In this article the solution conformations of two chimeric IgG3 antibodies were studied using this coupled triple detection technique. Conclusions indicate that the results allow hydrodynamic modeling of the antibody structures.

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Peter Myers from the University of Liverpool (Liverpool, UK) spoke to David McCalley from the University of the West of England (Bristol, UK) about the past, present, and future of stationary phases, and his working life in academia and industry.

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Following on from a previous instalment, this month's column assesses evaporative light-scattering detection as a complementary detection mode and builds upon the previous discussion in terms of detector applications.

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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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Microflow LC–MS-MS has seen a surge of attention, development, and popularity among research scientists and bioanalysts over the last few years. The potential of this technology to provide better sensitivity, less solvent waste, near-zero dead volume, and high through-put are a big part of this renewed interest. However, microflow LC techniques are hardly a new idea. More than 40 years ago, in 1974, a group at Nagoya University in Japan first developed a microcolumn liquid chromatography system, elements of which can be found in today’s commercial products. With the advances in technology over the last several years, development and implementation of this technique have been kicked into high gear. In this article, we discuss the history of microflow LC–MS-MS, the current state of the art, and where the future might lead for this rapidly growing technology.

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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.

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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.