Ionization Efficiency for Environmentally Relevant Compounds Using APPI Versus EI
September 1st 2021Atmospheric pressure photoionization (APPI) and electrospray ionization (ESI) are assessed for the mass spectrometry (MS) quantification of pharmaceuticals frequently detected in environmental waters, including antibiotics, beta blockers, and selective-serotonin reuptake inhibitors.
But My Peaks Are Not Gaussian! Part 2: Physical Causes of Peak Asymmetry
September 1st 2021Several physical phenomena can lead to asymmetric peak shapes, including heterogeneity of the particle density inside the column, rearrangement of the particles over time, and accumulation of debris at the column inlet frit. This month’s instalment will focus on these potential physical causes.
Remembering Harold McNair: Three Fundamental Areas of Understanding in Gas Chromatography
September 1st 2021Professor Harold Monroe McNair, among the original icons of chromatography, passed away on 27 June 2021 at the age of 88. In this tribute to the remarkable man and using his works as a guide, we explore three fundamental areas of understanding in GC, seeing ideas about problems that still challenge gas chromatographers today.
A Novel 3D-Printing Method to Create Liquid Chromatography Columns
September 1st 2021For approximately a decade, 3D-printed columns have been hailed as the future of LC. However, the resolution of typical printing methods has fallen short of the requirements to make an effective analytical or preparative-scale column. In this article, we describe a new 3D-printing method that can create large-volume columns with a feature resolution of 10 μm.