In this instalment, we focus on the impact of elution mode (isocratic or gradient) and postcolumn flow splitting on the total level of extracolumn dispersion (ECD) in a liquid chromatography (LC) system, and demonstrate the use of a free, web-based calculator that can be used to guide decision making aimed at reducing ECD during method development.
Extra column volume is the volume in an HPLC system external to the column that contributes to the total peak volume, which will impact peak width, resolution, and overall efficiency.
A rapid LC–MS method using ESI coupled with SIM-MS for analysis of humulone and isohumulone content in beer is described.
Untargeted GC–MS metabolomics with sample derivatization is shown here to be effective for measuring the chemical profiles of traditional and plant-based meat products.
Low-pressure gas chromatography (LPGC)–MS should be the first option in many GC–MS applications to provide fast, sensitive, and robust analyses; and the installation, instrumentation, and implementation of LPGC is possible in any GC–MS system.
A novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method with a dual electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI) source was developed for analysis of 66 pesticides and 5 mycotoxins regulated by the State of California in medium-chain triglyceride (MCT) oil cannabis tinctures. The limits of quantitation (LOQs) of all of the pesticides and mycotoxins were well below California state action limits of these analytes in cannabis-based non-inhalable or edible products. A total of 62 (out of 66) pesticides and 5 mycotoxins were analyzed using LC–MS/MS with an ESI source, and the remaining 4 pesticides were determined using LC–MS/MS with an APCI source. A simple, fast, and cheap acetonitrile solvent extraction method was used for sample preparation to get good recovery and achieve high throughput for this analysis. For late-eluted analytes, a number of internal standards were used to compensate for ion suppression effects from the hydrophobic matrix.
Better sample preparation and miniaturized separations are enhancing these analyses.
The authors developed an ion chromatography method to separate 31 cations in a single chromatographic run using inductively coupled plasma–mass spectrometry, liquid scintillation counting, and gamma counting. The high-level radioactive waste samples contained trace radionuclides in concentrations of only a few hundred disintegrations-per-minute-per-milliliter.
Online SPE–LC–MS/MS combined with the method presented enabled automated cleanup of food extracts and determination of PFAS compounds in the ng/kg range.
Acoustic ejection mass spectrometry (AEMS) has recently emerged as the premier ultrahigh-throughput mass spectrometric methodology for drug discovery and related fields.
In this article, the authors describe a simple workflow to develop a GC×GC method for a specific sample upon initial use, with the aim of decreasing the time to accomplish functional workflows for new users.
The authors introduce a new high-throughput approach for analyzing environmental micropollutants.
In electromembrane extraction (EME), the target analyte is extracted from an aqueous sample across a supported liquid membrane (SLM) and analyzed using LC. Through the study presented here, we demonstrate the principles of the technique and test its performance.
Capillary electrophoresis (CE) is a useful and versatile technique for a large number of applications. Devoting some discussion to the development of these reported methods to illustrate the separation approaches and strategies to obtain reproducible results, they also compare CE's advantages and disadvantages with those of the more typical method for each type of analysis.
Employing ion mobility at atmospheric pressure without vacuum enables coupling to high-resolution mass analyzers. High performance ion mobility–orbital trap mass spectrometry (HPIM-OT-MS) is a useful alternative for separating isomers, such as isomeric metabolites seen in drug discovery.
This information is supplementary to the article “Non-aqueous Ion-Exchange Chromatography Using High Acid‑base Concentration: A Strategy for Purifying Non-crystalline Pharmaceutical Intermediates” that was published in the March 2022 issue of LCGC Asia Pacific.
Analysis of the compositional variation in living cells is essential for understanding biological processes. Single-cell elemental analysis by triple-quadrupole ICP-MS is emerging as a selective, highly sensitive, and potentially high-throughput technique for the study of constitutive elements, and uptake of metallodrugs (or metal-containing nanomaterials) in single cells.
The authors demonstrate a new detection method for various anions and cations separated by ion chromatography and point out the main advantages of this method.
Errors arising from the DNPH approach commonly used to analyze carbonyl compounds in smoke from heat-not-burn (HNB) tobacco can be avoided by using the approach described in this study.
Decomposing animal tissue releases volatile organic compounds (VOCs), of interest in forensic science. We describe the use of GC×GC–qMS/FID retrofitted with a reverse fill/flush (RFF) flow modulator for analyzing these VOCs in a tropical climate.
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Computer-enabled technology approaches can mitigate the impact of aging instruments and instrument differences—leading to more robust, lower-maintenance analysis in industrial settings.
In the present study, a gradient reversed-phase high-performance liquid chromatography (RP-HPLC) method has been designed and validated to quantify ornidazole (OZ) in the marketed formulation (oral gel) with the application of QbD.
A look at the practical benefits of using TIMS-TOF MS in spatial biology applications.
This application note demonstrates a multistep thermal extraction study on tetrahydrocannabinol (THC) vape oils.
How to speed up sample prep time and equivalent acccuracy and precision.
In this edition of the LCGC Blog, Amber Hupp of the College of the Holy Cross provides advice for aspiring analytical chemists and shares accounts of other professionals.
The article discusses the classification and characterization of GC×GC column sets based on polarity and orthogonality, introducing a standardized approach using a reference mixture called the Century Mix to evaluate the selectivity and performance of these column sets.
The role of software to identify and distinguish seized drug samples.