When the Wrong Way is Better: Using Wrong-Way-Round Ionization for the Targeted Analysis of Pharmaceuticals in Wastewater
Spectroscopy E-Books
Effluents from wastewater treatment plants (WWTPs) are a major source of contamination by pharmaceuticals and personal care products (PPCPs) in the environment. The presence of low levels of PPCPs in surface and drinking water sources raises public concern because of the potential detrimental ecological effects of these contaminants. Because of these concerns, scientists and engineers have been interested in detecting PPCPs in water to evaluate their fate and transport in the environment, as well as monitor their transformation and degradation at WWTPs. Liquid chromatography coupled with mass spectrometry (LC–MS) has been the method of choice for separation and detection of PPCPs, because PPCPs are highly soluble in water and have low volatility. The majority of LC–MS methods use electrospray ionization either in positive or negative mode, with an acidic or basic mobile phase, respectively. As an alternative, this article presents the use of “wrong-way-round ionization” in electrospray mass spectrometry, where protonation of neutral or weakly basic molecules occurs in a strongly basic mobile phase in LC–MS. When “wrong-way-round ionization” was employed in LC–MS for the analysis of PPCPs in wastewater samples, increased signal intensities, by at least an order of magnitude, were observed in PPCPs with diverse polarity and acidic properties.
Read more
.
Getting accurate IR spectra on monolayer of molecules
April 18th 2024Creating uniform and repeatable monolayers is incredibly important for both scientific pursuits as well as the manufacturing of products in semiconductor, biotechnology, and. other industries. However, measuring monolayers and functionalized surfaces directly is. difficult, and many rely on a variety of characterization techniques that when used together can provide some degree of confidence. By combining non-contact atomic force microscopy (AFM) and IR spectroscopy, IR PiFM provides sensitive and accurate analysis of sub-monolayer of molecules without the concern of tip-sample cross contamination. Dr. Sung Park, Molecular Vista, joined Spectroscopy to provide insights on how IR PiFM can acquire IR signature of monolayer films due to its unique implementation.
