Author
Latest:
Enhanced Sample Throughput for Environmental AnalysisAs environmental legislation becomes more stringent, the need to deliver quantitative results in shorter times and greater volumes is necessary for routine environmental analysis. Most of the high-throughput screening methods used to analyze pharmaceutical compounds are, however, useless for environmental monitoring. This is because these methods primarily aim to retrieve as much information from a single sample using the broadest range of techniques. The chromatographic separation process is considered to be the bottleneck in the process. This is not the situation for environmental procedures, in which the bottleneck is the sample preparation step and is usually very tedious and time-consuming.
Latest:
Advances in Supercritical Fluid Chromatography for the Analysis of Chiral and Achiral PharmaceuticalsThis article provides an overview of the most recent advances in the field of chiral and achiral separations in SFC. This involves research focused on the most critical parameters in SFC separations, but also on practical issues such as the serial coupling of columns.
Latest:
Breaking Down Barriers: Can LC–MS Revolutionize the Quantitation of Drug Product Impurities?The authors test and compare performance of three types of LC–MS systems for precision, linearity, selectivity, accuracy, and sensitivity in the quantitation of drug impurities.
Latest:
LC–MS-MS Total Drug Analysis of Biological Samples Using a High-Throughput Protein Precipitation MethodThis article describes the use of a 96-well, solvent-resistant filtration plate for total drug analysis in blood plasma.
Latest:
Review of Chiral Stationary Phase Development and Chiral ApplicationsThe development of chiral column technology since the review in 2008 is discussed by Thomas Beesley.
Latest:
Identifying Differences in Solution Conformations of Two Chimeric IgG3 Antibodies through Triple Detection SECSize 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.
Latest:
Identifying Differences in Solution Conformations of Two Chimeric IgG3 Antibodies through Triple Detection SECSize 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.
Latest:
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.
Latest:
System Suitability and Validation for Chiral Purity Assays of Drug SubstancesMeasurement of chiral purity is a necessary means of quality control for drug substances that exhibit chiral centers. This article describes a simple and practical approach to setting up system suitability and validation for chiral purity assays.
Latest:
Microdialysis Sampling - Challenges and New FrontiersThis 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...
Latest:
Evaluating Analytical Instrumentation Using the Golf Score Card ToolThe use of a simple Excel-based "Golf Score Card" tool can facilitate assessments and instrument acquisistion decisions by collating and weighting the relative importance of the many criteria that impact the final purchase decision. The authors describe this process.
Latest:
HPLC 2022 Event PreviewThe 50th International Symposium on High Performance Liquid Phase Separations and Related Techniques (HPLC 2022) returns to the USA this summer.
Latest:
Enhanced Sample Throughput for Environmental AnalysisAs environmental legislation becomes more stringent, the need to deliver quantitative results in shorter times and greater volumes is necessary for routine environmental analysis. Most of the high-throughput screening methods used to analyze pharmaceutical compounds are, however, useless for environmental monitoring. This is because these methods primarily aim to retrieve as much information from a single sample using the broadest range of techniques. The chromatographic separation process is considered to be the bottleneck in the process. This is not the situation for environmental procedures, in which the bottleneck is the sample preparation step and is usually very tedious and time-consuming.
Latest:
Analysis of Polybrominated Diphenyl Ethers Using the Clarus 500 GC–MSThis application note will demonstrate a GC–MS analysis of common polybrominated diphenyl ether (PBDE) congeners. An optimized method will allow the Clarus GC–MS to provide ample separation and high yields of all PBDE congeners. The extended mass range of the Clarus 500 MS and high-mass calibration will produce mass spectra with very high levels of accuracy.
Latest:
Evaluating Analytical Instrumentation Using the Golf Score Card ToolThe use of a simple Excel-based "Golf Score Card" tool can facilitate assessments and instrument acquisistion decisions by collating and weighting the relative importance of the many criteria that impact the final purchase decision. The authors describe this process.
Latest:
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.
Latest:
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:
Amide Hydrogen–Deuterium Exchange: A Fast Tool for Screening Protein Stabilities in ChromatographyProtein 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.
Latest:
Automation of the Chromatographic Analytical Method Validation ProcessThis 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.
Latest:
Sorptive Tape Extraction — A Novel Sampling Method for the in vivo Study of SkinAn important prerequisite of a good sampling procedure for skin sebum is its reproducibility.
Latest:
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.
Latest:
Identifying Differences in Solution Conformations of Two Chimeric IgG3 Antibodies through Triple Detection SECSize 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.
Latest:
Going Through PhasesPeter 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.
Latest:
Success with Evaporative Light-Scattering Detection, Part II: Tips and TechniquesFollowing 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.
Latest:
Microdialysis Sampling - Challenges and New FrontiersThis 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...
Latest:
Microflow LC–MS-MS: The Past, the Present, and the Path ForwardMicroflow 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.
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.
