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.

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.

This Application Note demonstrates the optimization of a separation method for the determination of pesticides in a complex food matrix by supercritical fluid chromatography (SFC) with triple quadrupole MS detection.

An important attribute of a novel ionization process for use in mass spectrometry (MS) is its simplicity and flexibility to be hyphenated to conventional liquid-based separation methods.

The statistical overlap theory (SOT) of chromatography relates the number of peaks that appear in a chromatogram to the number of detectable components and the peak capacity.

A liquid chromatography–electrospray ionization tandem mass spectrometry (LC–ESI-MS-MS) method has been developed to determine multiple preservatives in cosmetics and personal care products.

Enhanced-fluidity liquids are organic solvents or organic–aqueous solvents mixed with high proportions of liquefied gases, such as carbon dioxide.

The most significant recent advancement in liquid chromatography (LC) column technology is the new generation of superficially porous silica particles.

Internal standard methods are used to improve the precision and accuracy of results where volume errors are difficult to predict and control.

Due to the highly polar nature of saccharides, the analysis of sugars is typically achieved using Hydrophilic Interaction Chromatography (HILIC). Using a high polarity packing material, separation is based on the hydrophilic interactions of the sugars on the stationary phase surface typically using an eluent with a majority of polar organic solvent.

Cooking at high temperatures causes a chemical reaction between certain sugars and asparagine which causes acrylamide formation. In this technical note, we explore how to use Novum™ SLE tubes to clean up a coffee matrix in order to quantitate known acrylamide levels. The recovery is especially significant when you consider the polar nature of the acrylamide (LogP -0.27). In addition to high recoveries (>90 %), the low values for the standard deviation and %CV indicates method reproducibility.

Cooking at high temperatures causes a chemical reaction between certain sugars and asparagine which causes acrylamide formation. In this technical note, we explore how to use Novum™ SLE tubes to clean up a coffee matrix in order to quantitate known acrylamide levels. The recovery is especially significant when you consider the polar nature of the acrylamide (LogP -0.27). In addition to high recoveries (>90 %), the low values for the standard deviation and %CV indicates method reproducibility.

Have a problem with your LC system? Maybe applying a little "DDT (Don't Do That)" may help.

The ideal UV detector would allow us to monitor the presence of our target analytes without influence from the background eluent and sample matrix components that may be present in the detector measuring cell at the same time

LCGC recently spoke with the 2014 LCGC Emerging Leader in Chromatography award winner, Andre de Villiers, an Associate Professor of Science at Stellenbosch University in South Africa, about his current research analyzing natural products, his various interests and collaborations in analytical chemistry, and his role as a teacher.

Controlling particle size distribution is examined as a possible route to further improve the performance of particle-based columns.

A review of LC methods and strategies for the chromatographic separation of short RNA oligonucleotides

Noteworthy new HPLC systems and related products

If scaling isocratic separations is so simple, why is gradient scaling so confusing?

The mechanisms of mixed-mode chromatography are explained, with reference to the parameters that are used to optimize selectivity and retention.

This article focuses on the progression that chiral stationary phases (CSPs), specifically developed for HPLC, are currently undergoing because of the pressing need of an easy switch to UHPLC.

For proper column installation it is important to be familiar with column characteristics such as solvent compatibility, maximum flow rate, and maximum operating temperature.

What kind of adjustments need to be made when scaling an isocratic method?

A simple and fast ion-pair chromatography method to detect sodium alkyl sulphates in environmental samples using conductivity detection is described.

Joe Pesek answers questions about IEX, HILIC, polar-embedded, and polar-endcapped columns, and aqueous normal phase chromatography.