UHPLC

Exploring the impact of green chemistry on analytical chemistry and GC is the focus of this instalment of "GC Connections".

A rapid and robust LC–MS/MS method for determining lactulose and rhamnose concentrations in blood plasma was used to determine intestinal permeability from blood plasma, which can help diagnose gastrointestinal diseases such as Crohn’s disease.

Everyone is talking about sustainability, and organizations are creating sustainability programs. But what does green chemistry really mean, and how does it apply to gas chromatography?

Selective pressurized liquid extraction and multilayer solid‑phase extraction methods are described for high‑throughput plant, soil, and water sample preparations. Optimal analytical conditions are described for the improvement of detection sensitivities and coverage. A Source Supported Suspect Screening (4S) approach is described; phytotoxins detected in the source plant were used to improve the identification of phytotoxins in soil and water.

Serial coupling of different column types can provide several important benefits to the chromatographer, including fine-tuning selectivity to separate complex mixtures.

In this extended special feature to celebrate the 35th anniversary edition of LCGC Europe, key opinion leaders from the separation science community explore contemporary trends in separation science and identify possible future developments.

In this extended special feature to celebrate the 35th anniversary edition of LCGC Europe, key opinion leaders from the separation science community explore contemporary trends in separation science and identify possible future developments.

This review article summarizes the results obtained from the combined efforts of a joint academic and industrial initiative to solve the real-life challenge of determining low levels of peptide-related impurities in the presence of the related biologically-active peptide at a high concentration.

An UHPLC–MS research prototype instrument was built to improve the resolution power and the usability of conventional LC–MS hyphenated instruments for routine analyses in pharmaceutical applications.

James P. Grinias is an Associate Professor in the Department of Chemistry & Biochemistry at Rowan University in Glassboro, New Jersey, and the winner of the 2022 Emerging Leader in Chromatography Award, which is presented by LCGC magazine.

In this series of blog posts, I’m going to explore how the challenges of adopting methods from the literature, or from internal or external clients, can often be made easier, and more enjoyable, by taking time for some detective work prior to even entering the laboratory.

This article quantifies the progress in speed and efficiency that has been made in the area of liquid chromatography (LC) over the past 50 years. After a decade of groundbreaking advances in the 1970s, the progress in chromatographic performance over the ensuing four decades (1980–now) follows Moore’s law relatively closely. This is characteristic of technological fields that are of an evolutionary nature (that is, driven by the need for better performance).

A series of theoretical, visualization, and simulation tools that are used to improve the structure and chemistry of the next generation of liquid chromatography (LC) columns is briefly reviewed.

This is the third in a series of articles exploring current topics in separation science that will be addressed at the HPLC 2019 conference in Milan, Italy, from 16–20 June.

The effect of dwell volume on chromatographic selectivity can be successfully modelled using retention prediction software. Hence, the robustness of reversed-phase LC gradient methodologies, with respect to dwell volume, can be conveniently assessed.

What are the most useful chromatography books on your bookshelf? What are the most useful web-based resources (such as websites, downloadable documents, videos) about separation science? What are the most useful tools supporting your work (such as calculators and simulators)? In this installment, Dwight Stoll compiles input from the separation science community (both individuals and vendors) to guide you to the resources that people find most useful.

To address the challenges of analyzing new illicit drugs, emerging techniques such as UHPSFC with MS and UV detection, and GC with VUV detection, may be needed, particularly for distinguishing positional isomers and diastereomers.

The three-day Chromatographic Society meeting was held on Monday 15th until Wednesday 17th May 2017 and was hosted by Pfizer at Discovery Park in Sandwich, Kent, UK. This comprehensive symposium featured oral presentations from leading practitioners of supercritical fluid chromatography (SFC) and ultrahigh-pressure liquid chromatography (UHPLC) from throughout Europe. Some of the latest innovations and applications were described and the lectures were augmented and supported by a comprehensive exhibition of instrumentation and consumables. The attendees gained insight into practical application of these techniques across a variety of industries-particularly the pharmaceutical industry. As was anticipated, in a comprehensive programme there was a significant focus on SFC for chiral and preparative-scale analysis.

John shares lessons learned from his more than three decades of teaching liquid chromatography practitioners and helping them solve their problems.

This instalment in our series on ultrahigh-pressure liquid chromatography (UHPLC) highlights its benefits in fast analysis, high-resolution separations, high performance liquid chromatography (HPLC) method development, reduced solvent and sample usage, and enhanced sensitivity and precision performance.

In this three-part series, we assess how UHPLC evolved into a modern platform. We start by examining the most important features common to most commercial instruments.

A recent argument was raised in the scientific press that in pursuit of greater speed and separation resolution, ultrahigh performance liquid chromatography (UHPLC) is faced with practical limitations and will struggle with its own version of Moore’s law.

Environmental analyses of food, soil, and water have changed dramatically over the last decade. Topics such as pesticides, food additives, and natural products have become important as food products are globally grown and distributed (1). Monitoring their quality is critical to international business. Pharmaceuticals, fluorinated surfactants, and endocrine disruptors in water are major new topics, where not only parent compounds are unknown but also their metabolites and degradation products are often more important or more abundant than the parent compound (2). New environmental issues, such as hydraulic fracturing and its wastewater, have captured our attention as the production of oil and gas has increased exponentially in the past decade (3). With this technology comes the problem of wastewater disposal and groundwater contamination. These environmental issues have greatly benefited from the combination of ultrahigh‑performance liquid chromatography (UHPLC) mated to high resolution mass spectrometry (HRMS

Chromatographic techniques with mass spectrometric detection are important enablers in modern drug discovery. With the development of robust instrumentation and implementation of user-friendly software (or software packages), non-expert users can now walk up to easily accessible advanced chromatographic systems and perform experiments at their own convenience. Although remarkable improvements in robustness and ease-of-use have happened since the introduction of the first high performance liquid chromatography–mass spectrometry (HPLC–MS) systems, the instrument performance still needs to be qualified and monitored to ensure consistent high-quality results. This article will demonstrate how a simple test mixture of carefully selected compounds can facilitate both the development of generic ultrahigh-pressure liquid chromatography–mass spectrometry (UHPLC–MS) methods and automated performance monitoring of multiple instruments located in separate laboratories and buildings.

There is increasing demand to analyze samples with a wide range of polarities, in fields such as environmental analysis and proteomics.

The free spreadsheet-based program HPLC Teaching Assistant was developed for effective and innovative learning and teaching of liquid chromatography. This software allows teachers to illustrate the basic principles of high performance liquid chromatography (HPLC) using virtual chromatograms (simulated chromatograms) obtained under various analytical conditions. In the first instalment of this series, we demonstrate the possibilities offered by this spreadsheet to illustrate the concept of chromatographic resolution, including the impact of retention, selectivity, and efficiency; understand the plate height (van Deemter) equation and kinetic performance in HPLC; recognize the importance of analyte lipophilicity (log P) on retention and selectivity in reversed-phase HPLC mode; and manipulate or adapt reversed-phase HPLC retention, taking into account the acido-basic properties (pKa) of compounds and the mobile-phase pH.

UHPLC instruments from different manufacturers and instruments with different configurations can produce significant variations in chromatographic separation. The variety in instrument configuration increases the complexity of the method development process, which now requires a more thorough evaluation of the effect of instrument variations on the method. The studies presented here determined the typical inter-instrument variations in dwell volume, extra-column dispersion, and mixing efficiency as measured by mobile phase compositional accuracy. Additionally, the dwell volume and extra-column dispersion were independently and systematically varied to evaluate the resulting impact on resolution for a small molecule test mixture during gradient elution. To account for these inter-instrument variations, dwell volume and wash-out volume method translation and adjustment techniques were evaluated.

Tips and tricks to get the most from your UHPLC system

Tricks and tips on recognizing, fixing, and preventing common issues associated with solid phase extraction and other common methods of sample preparation