All News

figure 1 L1537541918389.png

The Column

Approximately 40% of recombinant proteins that are purified use a histidine tag for easy capture. This article covers how to automate the purification of histidine-tagged proteins and how purification conditions can be optimized to an automated four-step purification scheme that uses affinity-, ion exchange-, and size-exclusion columns. Using a multistep purification scheme removes the manual steps that cause loss of precious proteins and take more time, like dialysis, collection, and reinjecting samples. The final purification scheme reduces a 3–4-day process to 11.5 h from start to finish, all while improving reproducibility, yield, and comparable purity.

Let’s first properly define carry-over in the context that I’d like to discuss here. An injection is made and a chromatogram obtained. On injecting a “blank” as the next injection, one or more of the components of the previous injection appear in the “blank” chromatogram.

I just finished a 10-month stint as Interim Associate Dean for Research and Development in the College of Science at The University of Texas Arlington. I was afforded that opportunity when some restructuring in another college left a temporary vacancy, which I was asked to fill. I certainly considered it an honor to be asked to serve in that role, but the temporary nature of that role also piqued my interest. For me, it seemed like a chance to do an internship in administration, to see if I liked it or not. I worked with great people, I did not really like the role.

figure 1.png

LCGC Europe

Column-based liquid phase separation techniques, such as liquid chromatography (LC) in reversed phase separation mode and capillary electromigration techniques, using continuous electrolyte systems, are widely used for the identification and quantification of phenolic compounds in plants and food matrices of plant origin. This paper is the first of a two-part review article discussing fundamental and practical aspects of both LC and capillary electromigration techniques used for the analysis of phenolic compounds occurring in plant-derived food and in edible and medicinal plants. The chemical structure and distribution of the major phenolic compounds occurring in the plant kingdom, as well as the main methods used for their extraction and sample preparation, are also discussed. Part 1 will focus on liquid chromatography.

LCGC Europe

The quality of a gas chromatogram depends heavily on the quality of the separation and detection gases, among many other factors. In this month’s instalment, “GC Connections” discusses ways in which chromatographers can ensure a safe working environment while delivering gases that are up to the requirements of the separations at hand, in the context of moving a laboratory to a new location.

figure 1 L.png

LCGC Europe

This is the second of three articles looking at the impact of the new United States Pharmacopeia (USP) on analytical instrument qualification (AIQ) on data integrity in a regulated chromatography laboratory. This part focuses on how the laboratory should supervise the execution of operational qualification (OQ) protocols by a third-party service provider. The principles described also apply to in-house metrology departments.

figrue 1 S.png

LCGC Europe

Liquid chromatography–mass spectrometry (LC–MS) has become the preferred analytical technique for many challenging assays based on its selectivity, sensitivity, and broad applicability to compounds of varying polarity. Despite its advantages, the complexity of LC–MS systems often leaves analysts struggling to meet method detection limits. In this instalment of “Column Watch”, several strategies will be discussed to improve method sensitivity through the reduction of contaminants, the careful selection of LC method conditions, and the optimization of MS interface settings. By understanding the relationship between these parameters and ionization efficiency, analysts can enhance their signal-to-noise ratio and realize the hidden potential of their LC–MS.

figure 1.png

LCGC Asia Pacific

Column-based liquid phase separation techniques, such as liquid chromatography (LC) in reversed phase separation mode and capillary electromigration techniques, using continuous electrolyte systems, are widely used for the identification and quantification of phenolic compounds in plants and food matrices of plant origin. This paper is the first of a two-part review article discussing fundamental and practical aspects of both LC and capillary electromigration techniques used for the analysis of phenolic compounds occurring in plant-derived food and in edible and medicinal plants. The chemical structure and distribution of the major phenolic compounds occurring in the plant kingdom, as well as the main methods used for their extraction and sample preparation, are also discussed. Part 1 will focus on liquid chromatography.

figure 1 L1537523311276.png

LCGC Asia Pacific

While capillary gas chromatography has been undergoing a renaissance, with new columns, detectors, data systems, and multidimensional separations, the classical inlets have remained the same: We are still injecting liquid samples with syringes into split and splitless inlets, as we have for nearly 50 years. Split and splitless injections present several well-known and some not-so-well known challenges, mostly arising from heating of the inlet, that make sample injection and inlets a major hurdle for gas chromatographers. These challenges and some ideas for mitigating them are discussed and a case is made for renewed exploration of the cool inlets and injection techniques: cool on-column and programmed temperature vaporization.

figure 1 L1537522729157.png

LCGC Asia Pacific

The use of superficially porous particles (SPPs) for modern high performance liquid chromatography (HPLC) is now very common. Initially, SPPs rose as an alternative to sub-2-µm fully porous particles (FPPs). In recent years, many column manufacturers have developed 2-µm and smaller SPP-based products. This article investigates the practical utility of these smaller SPP designs.