Fundamental Questions

As you hurry through your daily work in the analytical laboratory, are you failing to ask yourself some fundamental questions about the methods you use and the results you produce?


This collection of short articles from LCGC’s digital magazine, The Column, raises four key questions you should ask. And if the answers aren’t what you hoped, we offer advice for addressing the gaps.


Read more.

Liquid Chromatography

Preview of Topics at HPLC 2016, IV

By Alain Beck, Arnaud Delobel

As a result of advances in multilevel state-of-the-art mass spectrometry (MS) methods, combined with chromatographic and electrophoretic techniques, very precise characterization of biotherapeutics such as monoclonal antibodies (mAbs) and antibody drug conjugates (ADCs) is now possible. Until recently, however, these techniques were considered suitable only for research use. With the advent of robust and user-friendly solutions, these techniques are now amenable for routine use, as illustrated by examples of applications of the characterization of mAbs and ADCs. This is the fourth in a series of four articles exploring topics that will be addressed at the HPLC 2016 conference in San Francisco, from June 19 to 24.

Preview of Topics at HPLC 2016, III:

By Andrew Alpert

Until recently, mass spectrometry (MS) was limited in the information it could supply regarding proteins larger than 40 kDa. The most recent instruments have broken through that limit, but proteins smaller than 40 kDa are still more easily detected in MS and can suppress the collection of data from larger proteins. This situation has created a demand for better separation of proteins upstream from the MS orifice. At present, though, this separation of proteins is something of a bottleneck. Methods such as reversed-phase chromatography that involve mobile phases compatible with MS are not compatible with many proteins. Alternative modes of chromatography include size-exclusion chromatography, ion-exchange chromatography, hydrophilic interaction chromatography (HILIC), and hydrophobic interaction chromatography (HIC). We decided to take another look at HIC. This is the third in a series of articles exploring topics that will be addressed at the HPLC 2016 conference in San Francisco, from June 19 to 24.

Preview of Topics at HPLC 2016, II:

By Mary J. Wirth, Alexis Huckabee, Jonathan Yasosky

Separations of intact proteins play many roles in drug discovery and development. A variety of separation techniques are used, from immunoprecipitation for study of a single protein of interest, through various types of column chromatography for detecting a handful of proteins at once, all the way to proteomics for studying hundreds to thousands of proteins. What all of these techniques and applications have in common is that the power of protein separations is limited by the fact that proteins are large, slowly diffusing, sticky molecules. This article discusses various chromatographic approaches to addressing this challenge. This is the second in a series of articles exploring topics that will be addressed at the HPLC 2016 conference in San Francisco, from June 19 to 24.

Gas Chromatography

How to Tackle an Unknown: Notes from the Fourth Method Development Olympics at CoSMoS

By Michael P. Balogh

How would you analyze a bag of gummy bears that showed up on your laboratory bench? This was the challenge taken on by teams of analysts in advance of the Conference on Small Molecule Science (CoSMoS) that was held in August 2015 in San Diego, California. This article shares insights from how the finalists approached the question.

Chromatographers Get Into Cannabis

By Tim Anderson

Gas chromatography (GC) is an established and well-understood technique. As the cannabis industry grows, demand for analytical robustness is increasing for analytes such as pesticides, residual solvents, and terpenes. GC and GC coupled to mass spectrometry (GC–MS) are effective tools to address the demands of laboratories, growers, manufacturers, and consumers. This article provides an overview of the types of compounds that can be analyzed by GC, reviews the strengths and weaknesses of the analytical methods, and discusses areas of opportunity for chromatography.

Improving Aroma Profiling of Hops by Headspace TD–GC–TOF-MS

By Stefan Koschinski, Laura McGregor, Gareth Roberts, David Barden

This article describes the use of a headspace thermal desorption–gas chromatography–time-of-flight mass spectrometry (headspace TD–GC–TOF-MS) method to analyze complex aroma profiles from hops, and highlights how it can provide a rapid yet robust approach when comparing similar samples. The article also examines the potential of “soft” electron ionization at 12 eV for distinguishing between structurally similar monoterpenoids and sesquiterpenoids to provide better characterization of the often subtle differences in headspace profiles between different hop varieties.

Mass Spectrometry

Desorption and Ionization Mass Spectrometry in Research Laboratories

By Giuseppe Astarita, Bindesh Shrestha

The three key applications for desorption and ionization techniques are rapid, in situ screening; direct analysis of extracted samples or planar chromatography spots; and scanning samples along x and y axes.

Extending the Hydrocarbon Range for the Analysis of Soil Gas Samples Using Automated Thermal Desorption Coupled with Gas Chromatography–Mass Spectrometry

By Lee Marotta, Stephen Varisco, Miles Snow, Tom Kwoka, Robert Thomas

When monitoring toxic gases emitted from the soil, it is often necessary to recover compounds with a boiling point above that of napthalene. The use of thermal desorption makes that possible.

Combining Raman Imaging, Mass Spectrometry Imaging, and AFM

By LCGC Editors

Imaging techniques using vibrational spectroscopy, MS, and atomic force microscopy have all been advancing and gaining momentum in recent years. There is great potential power in these imaging techniques, particularly in the biomedical field. Here, Thomas Bocklitz of the Friedrich-Schiller- University Jena discusses his work combining these techniques.

Sample Preparation

Trends in Sample Preparation

By Douglas E. Raynie

A comparison of the results from a new survey on sample preparation techniques to those of previous surveys, from 1991 to 2013, reveals some interesting trends.

Trends in Sample Preparation

By Ronald E. Majors

A survey of LCGC readers on sample preparation techniques and methodology investigated trends in technologies being used, sample loads, sample sizes, automation, the use of SPE devices (cartridges, disks, plates, tips), SPE chemistries, selection criteria, and problems encountered.

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LCGC Blog

The LCGC Blog: Practical HPLC Method Development Screening

By Tony Taylor

I often get asked about the other important aspects of “screening” in HPLC, which include the mobile phase composition, gradient parameters and flow rate – so that’s the theme of this installment.

First Considerations in the Design of a Comprehensive Two-Dimensional Liquid Chromatography Method

By Kevin A. Schug

Here, I will attempt to convey a few basic but critical concepts when getting started in the development of a new LCxLC method.

LCGC TV

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LCGC Slideshows

Slideshow: Seven Common Faux Pas in Modern HPLC

Seven outdated traditional practices that should not be performed without considering alternative approaches that can improve results, provide lower operation costs, or give faster run times. Instead of working harder, analytical scientists should work smarter. Learn more by clicking through the slideshow.

Slideshow: The Top 10 HPLC and UHPLC Column Myths

Webster’s New Collegiate Dictionary defines a myth as “an ill-founded belief held uncritically, especially by an interested group.” Could that group be misinformed chromatographers?

Latest News

Debby Mangelings Joins LCGC’s Editorial Advisory Boards

LCGC magazine is pleased to announce the addition of Debby Mangelings to the editorial advisory boards of LCGC North America and LCGC Europe.

Identification of Synthetic Colorants Using HPLC-DAD and Chemometrics

A team of researchers from the State Laboratory of Chemo/Biosensing and Chemometrics in China has developed a novel high performance liquid chromatography-diode array detection (HPLC-DAD) method for the identification of six synthetic colours in five beverages.

Characterizing New Psychoactive Substances

Researchers from the Joint Research Centre of the European Commission have published a case study detailing the characterization of new psychoactive substances using gas chromatography–mass spectrometry, nuclear magnetic resonance, high‑resolution tandem mass-spectrometry, and Raman spectroscopy.

LCGC E-Books

Fundamental UHPLC Workflows for Biotherapeutic Characterization

The introduction of UHPLC revolutionized bio/pharma analytical laboratories and advances in technology promise more for the future. In this e-book, experts explain recent advances in UHPLC, and the basics of glycan analysis.

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CHROMacademy

Peak Purity Algorithms using Diode Array Detectors

In an ideal chromatographic separation, all sample components would be isolated from each other and detected as fully resolved peaks. However, it is not uncommon to encounter some degree of overlap. In extreme cases, what appears to be a single peak contains in fact two or more coeluting components. This article discusses how to check the purity of such peaks in order to correctly interpret the results of the analysis.

Peak Purity Algorithms using Diode Array Detectors

In an ideal chromatographic separation, all sample components would be isolated from each other and detected as fully resolved peaks. However, it is not uncommon to encounter some degree of overlap. In extreme cases, what appears to be a single peak contains in fact two or more coeluting components. This article discusses how to check the purity of such peaks in order to correctly interpret the results of the analysis.

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