Liquid Chromatography (LC/HPLC)

During the course of my scientific career beginning in the 1960s, I have grown up with the birth of modern LC column technology, the refinements of the instrumentation, and the development of widespread application of this most powerful separation and analysis technique. In this installment, I would like to share with you some of my observations and experiences with the beginning, the growth period, and the maturation of HPLC columns, where I have focused nearly 33 years of writing for this magazine. I will explore some of the early column breakthroughs beginning with the development of large superficially porous particles (SPP), the porous irregular and spherical microparticulate particles, inorganic and organic polymeric monoliths and the rebirth of the current generation of SPP. In next month’s installment I will look into my crystal ball and see what the future of HPLC and UHPLC holds.

How to get started in the process of identifying the problem source for column-related problems.How to get started in the process of identifying the problem source for column-related problems.

So you think you know all about UV detection? Double check your understanding with this short primer on the principles and key variables of ultraviolet visible detection.

The capability to separate and analyze a wide range of proteins in complex systems remains a prime requirement in the biochemical sciences. Intact protein separations are especially difficult as these large molecules can present different conformations, association states and amphoteric features with chromatographic surfaces. Combining high performance liquid chromatography (HPLC) and ultrahigh pressure liquid chromatography (UHPLC) with mass spectrometry (MS) has proven to be an effective approach for solving difficult problems involving protein analyses. Considerable effort has been made to develop columns for separating proteins with high efficiency for reversed-phase, ion-exchange, size-exclusion chromatography, hydrophilic interaction liquid chromatography (HILIC), and hydrophobic interaction chromatography (HIC). Even so, many situations still exist where insufficient resolution is available for accurate protein analysis even when high-resolution MS is available. This presentation provides a brief overview of new approaches being investigated in the author's laboratories for obtaining superior protein separations. This includes new approaches for obtaining better protein separations with columns of highly-efficient superficially porous silica particles and techniques using MS-friendly mobile phases with effective methods for changing protein selectivity (band spacings) by column type and organic mobile phase modifiers.

This article provided guidance for working with the low-dispersion, small-volume columns that were gaining popularity in 2003. These considerations are still appropriate today with the short, narrow HPLC and UHPLC columns now in vogue. Anatomy

Advances in Liquid Chromatography–Tandem Mass Spectrometry (LC–MS–MS)-Based Quantitation of Biopharmaceuticals in Biological Samples

Analyzing Host Cell Proteins Using Off-Line Two-Dimensional Liquid Chromatography–Mass Spectrometry

Multi-Toxin Determination in Food – The Power of "Dilute and Shoot" Approaches in LC–MS–MS

Solvent costs too high? Here are some ideas on how to decrease the amount of mobile phase you use.

Miniaturized separation techniques are advantageous for the analysis of illicit drugs and new psychoactive substances.

I recently returned from a tour of teaching liquid chromatography (LC) classes to users in Minnesota, the United Kingdom, Poland, and Malta. One thing that always impresses me on such trips is that no one group has a corner on the LC problem market. The same problems pop up in most laboratories, no matter where they are located, the role of the laboratory (for example, analytical, forensic, production, research), what industry is involved, or the brands of instrumentation used.

HPLC 2015, chaired by Gérard Hopfgartner was held in Geneva, Switzerland, from June 21–25. This installment covers some of the highlights observed at the symposium including stationary phase developments, particle technology, and areas of growing application of HPLC. In addition, trends and perspectives on future developments in HPLC culled from the conference are presented.

This article presents a method for comparing the levels of baseline interference arising from common laboratory mobile phase contamination sources and assesses different approaches for removing dissolved contaminants to generate interference-free chromatogram baselines. The authors demonstrate that recirculating mobile phase through a semi-preparative scale column using a reagent delivery pump has advantages over previously published mobile phase decontamination methods.

The 42nd International Symposium of High Performance Liquid Phase Separations and Related Techniques (HPLC 2015), chaired by Gérard Hopfgartner was held 21–25 June in Geneva, Switzerland. This instalment covers some of the highlights observed at the symposium including stationary-phase developments, particle technology, and areas of growing application of HPLC. In addition, trends and perspectives on future developments in HPLC culled from the conference are presented.

Biopharmaceutical Candidate Screening with Automated Dynamic Light Scattering

The potential causes are considered for peak distortion for the first two peaks in the chromatogram.The potential causes are considered for peak distortion for the first two peaks in the chromatogram.

Here, we concentrate on one particularly useful equation that allows us to make changes to an analytical system to improve throughput or efficiency, while retaining the selectivity of the original method.

Tips & Tricks GPC/SEC: Answering Common Questions About GPC/SEC Columns

Where Can I Draw The Line?

This installment provides an overview of modern practices of high-throughput purification to support small-molecule drug discovery.

The use of superficially porous particles in the manufacture of high performance liquid chromatography (HPLC) columns has become prominent in recent years. Over the course of the past decade most major manufacturers have built column lines around the technology.

Readers' questions regarding problems related to internal standard calibration of liquid chromatography methods are addressed.

This work presents an on-line combination of a simple microgradient device for reversed-phase liquid chromatography (LC) and electrospray ionization (ESI) tandem mass spectrometry (MS-MS).

Changes to the European Food Safety Authority (EFSA) regulations on food labelling, and the strengths and limitations of new and existing methods for the detection of allergens in food are discussed in this article.

Beer is one of the most popular drinks in the world. Based on natural products, quality control to guarantee a product of consistent taste, colour, and composition can be challenging. Amino acids analysis can be used to ensure consistency in the quality of the end-product, and also as an indicator for counterfeiting of branded products. In this article we present a rapid and reliable high performance liquid chromatography–mass spectrometry (HPLC–MS) method to determine amino acids in beer.