Tony Taylor

There are many aspects of analytical science which abound with myth and legend – but gas chromatography – mass spectrometry (GC-MS), and more specifically the electron ionization (EI) process, stands out as the technique which has given rise to the largest number of ‘urban myths’ and misunderstandings.

There is a bewildering array of stationary-phase choices available for reversed-phase high performance liquid chromatography (HPLC), and even within each phase designation (such as "C18") the selectivity of each phase can vary widely.

A guide to selecting the correct HPLC stationary phase.

There are often times in my work when I need to 'mess about' with column dimensions and particle morphologies. For 'mess about' read improve or transfer.

Choosing the correct column selectivity and dimensions is fundamental to successful gas chromatography method development.

An excerpt from LCGC's e-learning tutorial on GC column selection at CHROMacademy.com

LCGC Blogger Tony Taylor asks if we are too scared to properly explore selectivity options in high performance liquid chromatography (HPLC).

A guide to HPLC detector selection.

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

To obtain sensitive, robust, and reproducible gas chromatography (GC) methods, each stage of the chromatographic process needs to be carefully considered and optimized. It is also important to record and report as much detail within the method specification so that the method can be reproduced between operators, instruments, and laboratories. Table I represents a "blueprint" method specification with all of the information that is necessary to faithfully specify and reproduce a split–splitless GC method.

An explanation of why HPLC eluent systems are designed as they are.

How to spot problems in your method before they become an issue.

How to spot weaknesses in methods before problems occur

An investigation into some "typical" HPLC method specifications to highlight ways of critically evaluating the major and minor parameters of a method

An overview of the analytical approaches used for the analysis of biomolecules

Is 0.1% TFA (aq) / 0.1% TFA in acetonitrile the ultimate robust HPLC mobile phase? Maybe not...

If you change your GC carrier gas to hydrogen or nitrogen, you will need to consider various aspects of how that change will affect your methods.

A series of real life problems submitted by ChromAcademy members

The power of MS-MS analysis applied to GC analysis, including the instrumentation, experiment types, and application areas

Why do core–shell particles provide an increase in efficiency?

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

Key considerations for setting up or troubleshooting a GC method.

Secondary parameters in the interface and mass analyzer can have a major impact on sensitivity and reproducibility. Here, we examine how and when to consider optimizing these parameters through a study of the working principles of LC–MS analysis.

In this technical tip from CHROMacademy we re-visit some of the lesser known or remembered facts relating to silica particles used in chromatography.

A review of the principles of these analyzers and their relative advantages and disadvantages over other mass analyzer types

We explain the working principles of the most popular of all mass analyzing devices.

An overview of the principles and equipment required for scaling analytical separations to the preparative scale and considerations for the scale of analyte required.

Achieving efficient analyte transfer between columns is critical to gaining the benefits of multidimensional GC.

Ion-exchange chromatography (IEC) is based on the different affinities of analyte and eluent counterions for the oppositely charged ionic functional groups on the stationary-phase surface of an exchange resin. Depending on the charge of the surface electrostatic groups, the resin could be either an anion exchanger (positively charged stationary phase) or a cation exchanger (negatively charged stationary phase).