Absolute Configuration by VCD
Determination of absolute configuration (AC) of chiral molecules is an important step in any field related to chirality but nowhere is it as critical as in the pharmaceutical industry. The phenomenon of “chiral recognition” − in which the enantiomers of a chiral drug may exhibit differences in biological activity or other processes such as distribution, uptake, and metabolism−makes it a necessity (or requirement) to know the AC not only of the final molecule but as early in the process of development as possible.
Absolute Configuration of Chiral Natural Products
Within the past few years it has been conclusively demonstrated that vibrational circular dichroism (VCD) is a reliable method for AC determinations. VCD offers a novel alternative to X-ray crystallography, permitting AC determinations on neat liquid, oil, and solution samples. VCD requires no derivatization of the sample or growth of a pure single crystal. VCD is defined as the difference in infrared (IR) absorption for left versus right circular polarization for a chiral molecule during a vibrational transition. VCD combines the structural specificity of vibrational IR absorption spectroscopy with the stereochemical sensitivity of a chi-roptical spectroscopy such as CD. The absolute stereochemistry is established by comparing the solution-phase VCD spectrum to the results of an ab initio quantum chemistry calculation. The calculations are easily carried out in commercial packages such as Gaussian (Gaussian, Inc., Pittsburgh, Pennsylvania).
Forensic Applications of Handheld RamTest™ Identifier
BioTools, Inc. (Jupiter, FL) has recently introduced the RamTest-CSI handheld Raman identifier well suited for forensic, CSI, homeland security, and other field applications. Unmatched field performance of this easy-to-use, light-weight unit is achieved by utilizing a small-size, state-of-the-art 532 nm excitation source combined with breakthrough engineering design and advanced analytical methodology. As a result, RamTest-CSI instrument is capable of 5-10x faster analysis / ID of chemicals compared to the other handheld Raman instruments currently available on the market.
Ram-532-NANO™ PortableRaman Analyzers: Superior Performance for Carbon Nanotubes Characterization and Quality Control
Due to their unique electronic, physical and mechanical properties, carbon nanotubes (CNTs) are being increasingly used in the fields of electronics and semiconductors, advanced materials, batteries and capacitors, aerospace and defense. The global CNTs / CNT-based product market is projected to reach 5.64 Billion USD by 2020, with annual growth rate (CAGR) of 20.1%.
As commercial CNT production increases, a need to control the quality of produced or purchased CNTs also increases. Raman spectroscopy is one of the most suitable analytical techniques for CNT characterization and/or quality control.
Fastest-In-Class Explosive Detection Using RamTest™ Raman Identifier
Data from Global Terrorism Database shows that number of terrorist attacks utilizing explosive devices has dramatically increased within last decade. Numerous analytical methods, including portable Raman, have been developed to enable detection of explosives, their precursors and / or breakdown products at the field. In this application note, it is directly demonstrated that RamTest-CSI Handheld Raman Identifier enables fastest-in-class ID of explosive materials (among handhelds), identification and quantitation of individual components in mixtures, as well as ability to analyze compounds previously considered impossible or hard-to-detect using handheld Raman (examples: ammonia, ammonium nitrate, RDX, biologics). Other CSI applications include but not limited to counterfeit testing (medicine, food, beverages or alcohol products), analysis of biological stains, etc.