The LCGC Blog: Solve Carryover Problems in Gas Chromatography
September 11th 2018Let’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.
The LCGC Blog: Analytical Chemistry is Central to All Modern Research
September 5th 2018I 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.
Instrument Considerations in the Transfer of Chromatographic Methods, Part I: Method Considerations
September 1st 2018In the first of a three part series, we discuss challenges associated with successful transfer of chromatographic methods and how to best circumvent and remove ambiguities and contradictions
Safely Delivering the Best Possible Carrier and Detector Gases to Your GC System
September 1st 2018The 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.
Data Integrity and USP , Part 2: OQ Supervision and Execution
September 1st 2018This 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.
LC–MS Sensitivity: Practical Strategies to Boost Your Signal and Lower Your Noise
September 1st 2018Liquid 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.
Split, Splitless, and Beyond—Getting the Most From Your Inlet
September 1st 2018While 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.
When Do We Need Sub2m Superficially Porous Particles for Liquid Chromatography Separations
September 1st 2018The 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.