Spectroscopy E-Books
The main objective of this study was to evaluate the capabilities of gas chromatography (GC) with time–of–flight mass spectrometry (MS) for screening pesticides in fruits and vegetables using a purpose-built accurate-mass database. Analytical performance was tested on four matrices: potato, tomato, spring onion, and orange. Two resolution modes, 7000 FWHM and 12,000 FWHM, were tested to establish the concentration range within which automatic identification was possible, considering the retention time window of 0.2 min and at least two ions with a mass error lower than 10 ppm as the identification criteria. The effects of the matrix on identification and quantification were also studied for the four selected matrices. The developed method was applied to real samples and the qualitative and quantitative results were compared with those obtained using GC with triplequadrupole MS.
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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.
Deep Level Transient Spectroscopy Reveals Influence of Defects on 2D Semiconductor Devices
April 25th 2024A recent study used deep level transient spectroscopy to investigate the electrical response of defect filling and emission in monolayer metal-organic chemical vapor deposition (MOCVD)-grown materials deposited on complementary metal-oxide-semiconductor (CMOS)-compatible substrates.