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.
The LCGC Blog: A Weighty Problem with Calibration
August 6th 2018Chromatographic methods often require that the analyte response is calibrated (and validated) over a wide concentration range when the analyte concentration in the sample is either unknown or is expected to vary widely. Bioanalysis, environmental, and clinical applications are just a few examples of where this may be the case.
The LCGC Blog: Multipath Liquid Chromatography–Mass Spectrometry: A Veritable Pandora’s Box
August 1st 2018For several years, our group has been working on a concept that we have termed multipath liquid chromatography (LC). The main idea is to target multiple classes of compounds following a single injection of a sample, the components of which are segregated on-line and directed to separate appropriate paths for simultaneous separation; the streams are then recombined for detection. I believe that this approach would be powerful for biomarker quantitation, where it would be more informative to track both metabolite and protein biomarkers to better define a disease state, or in the case of antibody–drug conjugate (ADC) development, where the metabolism of the ADC might involve understanding both the levels of the released drug and the remaining protein.