Improving Sensitivity and Selectivity in Pesticide Analysis with GC–MS and GC–MS-MS
Spectroscopy E-Books
The selection of analytical methods for gas chromatography (GC)-amenable pesticides is often based on requirements for sensitivity and selectivity for regulatory needs or other monitoring requirements. Methods with both electron ionization (EI) and negative chemical ionization (NCI) are often required to cover the full range of GC–amenable pesticides at trace levels. Pesticides fragment easily in EI and CI sources such that the molecular ion is often low in abundance. NCI can provide added selectivity and sensitivity over EI methods. NCI is most commonly used in selected-ion monitoring mode. The lack of availability of parent ions for collision-induced dissociation for tandem mass spectrometry (MS) can limit the feasibility of GC–MS-MS for pesticides that significantly fragment in the ion source. Options for improving sensitivity by using of large-volume cold on column or programmable temperature vaporizer injections are presented. Read more
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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.
Achieving 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.
