Join Magritek at EUROMAR 2019 in Berlin, Germany from 25 to 30 August 2019. You’ll get a chance to meet us, learn about our company and we’ll get you acquainted with the Spinsolve – high-performance benchtop NMR spectrometer that offers impressive sensitivity and resolution, it is robust and easy to use. We are looking forward to seeing you at this conference !!!
Magritek will be running a workshop on the Henry Ford Building, on Wednesday 28.08.2019 ( the Room number has to be confirmed ), for registration please contact Mauricio Ferreira – email@example.com
The conference will be taking place on the Dahlem Campus of the Free University, in the southwest of Berlin. The address of the main conference venue is:
Magritek will have a live Spinsolve system running experiments, we would love for you to visit us and talk to our team about the capabilities and applications of our latest Spinsolve Benchtop NMR Systems.
This week our team is at the excellent Magnetic Moments in Central Europe conference in Prague. Our applications team are there with a working Spinsolve and would be delighted to show you the Spinsolve NMR spectrometer in action. If you are attending please come by our booth to say hi and see the best benchtop NMR for yourself.
Join Magritek at EuropaCat in Aachen, Germany from 18 to 23 August 2019. You’ll get a chance to meet us, learn about our company and we’ll get you acquainted with the Spinsolve – high-performance benchtop NMR spectrometer that offers impressive sensitivity and resolution, it is robust and easy to use. We are looking forward to seeing you at this conference !!!
The conference will take place at Aachen, the “triple point of Europe”.
In Vietnam, for the observation of animals in the jungle of the national park of Cat Tien (and in other parts of the country and in Asia), the rangers give the tourists leech socks and a repellent cream for land leeches to put on the socks. Land leeches are terrestrial blood-sucking worm-like parasites. Reading the cream container, I noticed that it contains diethyl phthalate (DEP). Out of curiosity, I dissolved some of the cream in CDCl3 and acquired a NMR spectrum with the Spinsolve 80 MHz benchtop NMR spectrometer.
The 1D 1H spectrum confirms that the cream is mainly composed of diethyl phthalate (Fig. 1, a). A zoom of the spectrum (Fig. 1, b) shows the presence of some additional compounds overlapping with the 13C satellite peaks of DEP (0.55% of the main peaks). To simplify the identification of the additional compounds present in the cream I acquired a 1D 1H spectrum using the carbon decoupling protocol available in the Spinsolve software (Fig. 1, c). This method removes the satellites from the spectra making it possible to detect compounds dissolved at concentration smaller than 1% with respect to DEP.
Typical excipients used in such creams are fatty acid mixtures from butter and/or oils, glycerol/glycine, alcohol (multiplet ~ 3.5 ppm, CH2-OH) and PEG based compounds (peak ~ 3.6 ppm) and even perfume(s).
In our case, the fatty acid peaks are easily recognized. The terminal methyl of fatty acids is observed in region F around 0.8 ppm, the aliphatic chain in region E and probably under the CH3 of DEP, and the olefinic protons of saturated fatty acids around 5.2 ppm in the region A. As no signal is observed around 2.8 ppm, the saturated fatty acids present in the cream are mono unsaturated. The singlet at 2.47 ppm (singlet C) could be a residual solvent like DMSO or 1,3-dioxan, common solvents contaminating cosmetic cream. To check this hypothesis, ~ 2 µL of solvent was added. If the cream contains the solvent, the integral of peak C would increase, but in our case new peaks were observed (data not show). Region B correspond to a CH3 group next to a (mono or di) substituted aliphatic. The area D could be a triplet with a J coupling of 7 Hz. These peaks probably belong to a perfume, where the additional peaks of the perfume molecule overlap with peaks of DEP.
The best-selling Magritek 80 MHz Spinsolve benchtop NMR is also available with the X-channel set to 31-Phosphorus. 31P NMR spectroscopy is routinely used by chemists to determine structure and measure impurities. When looking for impurities it is important to know the lower limit of detection (LOD). The LOD is the lowest concentration of a molecule that can be distinguished from the absence of that molecule.
In NMR it is the sensitivity that determines the LOD for a particular substance, and the higher magnetic field of an 80 MHz magnet brings a number of advantages including increased sensitivity. We thought it would be interesting to determine the LOD for tetramethylphosphonium chloride with different acquisition times. We defined the LOD as an NMR peak with signal height that was 3 times the noise level, i.e. an SNR of 3.