Pulsar uses a permanent magnet which means that it requires neither liquid helium nor liquid nitrogen. Advanced, automatic shimming produces a highly homogeneous magnetic field meaning that Pulsar is suitable for use in almost any academic or industrial chemistry laboratory, for teaching, for organic synthesis analysis, or for materials identification. For many analyses, liquid samples can be run neat; solid samples can be dissolved in deuterated or non-deuterated solvents. Intuitive, step-by-step software takes the user seamlessly through the measurement process, and data is processed with the industry-renowned Mnova software. A library of pulse sequences is included, so everything is ready to go. The convenience and high performance of Pulsar means you get the power of NMR spectroscopy right where you need it – in your own lab.
The Pulsar NMR spectrometer from Oxford Instruments delivers affordable, high performance NMR spectroscopy into the laboratory environment.
NMR where you want it
Pulsar is a benchtop NMR spectrometer that offers high resolution performance without the need for liquid nitrogen, liquid helium or compressed gases. It uses a standard mains electricity supply, and has no special health and safety requirements. This means you can run NMR spectra in your own lab, close to your own process, without having to send samples away to a remote NMR facility and wait for the results. Of course, measurements by high-field NMR may still be needed from time to time, but Pulsar’s outstanding performance means a high proportion of measurements can be done instantly, on the spot – when you need them.
Pulsar uses standard 5mm NMR tubes, and has a highly efficient automated shimming routine that optimises the shim in just a few minutes when needed.
For simple 1D spectra, Pulsar has SoftLock – an advanced software lock that guarantees absolute spectral stability without the need for deuterated solvents. SoftLock is so effective that 2000 scans can be overlaid with no detectable line broadening from misalignment.
Pulsar offers a traditional deuterium lock for running 2D experiments.
Pulsar gives you class-leading performance, obtained using a 1.4T (60MHz proton resonance) rare-earth permanent magnet with superior homogeneity. The traditional design of the Pulsar magnet means that wellknown and understood shimming techniques can be used to achieve the best resolution available on any benchtop NMR instrument.
In addition to routine 'H spectra, every Pulsar can also acquire 19F spectra using the same probe. An example 19F spectrum of 5-bromo-1,2,3- trifluorobenzene is shown below. Pulsar is also ideal for arrayed experiments. Sequential acquisition of data during a chemical reaction provides a method for monitoring changes in specific functional groups during the reaction. Visual comparison of the pectra at different stages of the reaction is straightforward. An example shown below is the transesterification of a triglyceride.
NMR spectroscopy is an invaluable analytical technique for chemical analysis. The information from an NMR spectrum complements the information obtained from other types of instrumentation. In many cases it offers unique information about the sample material. NMR is an excellent technique for the identification of materials and chemical groups. These example spectra (below) show materials with the same molecular formula, C6 H10O2 , yet which are chemically different. The NMR spectra differ significantly even in the case of trans-2- and trans-3-hexenoic acids (a pair of structural isomers which consist of the same functional groups and chain lengths).
The spectral data obtained on Pulsar shows clear separation of the multiplets commonly observed in NMR spectra. The example below shows the typical multiplets generated by hydrogen atoms in an ethyl (CH3 CH2 -) group in the molecule.
Integration of the peaks provides a method for determining the number of hydrogen atoms present in each chemical group. The distance between the peaks in these multiplets allows measurement of the coupling constants
13C measurements are a common requirement in organic chemistry laboratories, and Pulsar offers outstanding 13C performance. The excellent sensitivity, resolution and lineshape of Pulsar mean that measurement of 13C compounds with sample concentrations down to 0.5 M is practical in less than 2 hours. Neat samples can give good results literally in minutes. Even with weaker samples the excellent stability of the Pulsar shims and frequency lock mean that high quality data can be collected in an overnight run.
In addition to 1D proton decoupled carbon, polarisation transfer experiments such as DEPT are available providing additional information about the number of hydrogen atoms attached to each carbon. The data from DEPT-45, DEPT-90 and DEPT-135 experiments can be combined in linear combination to produce edited spectra containing signals from only CH, CH2 and CH3 groups respectively.
2D 'H – 13C correlation experiments are also available.
Pulsar’s exceptional stability and high performance electronics allow a wide range of 2D homonuclear experiments to be carried out. These include:
COSY – classic 2D correlation spectroscopy providing information about mutually coupled nuclei and neighbouring atoms.
J-resolved – decoupling the chemical shift information from the J-coupling which helps separate overlapping multiplets.
TOCSY – exploits the connectivity through the J-couplings of an unbroken chain of coupled nuclei to provide information on the backbone structure of organic molecules.
Pulsar is also able to offer selective 1D TOCSY, which allows the user to quickly identify all the peaks coupled in an unbroken chain to the chosen peak.
Pulsar software is a combination of Oxford Instruments’ own SpinFlow graphical user interface, and Mestrelab’s powerful Mnova software.
SpinFlow enables the user to quickly and easily create routine experiments for spectra collection or relaxation measurements, using an intuitive, seamless workflow package. Automated setup routines ensure that the instrument can be optimised for peak performance by all users regardless of their level of expertise. Running a sample can be as simple as selecting the experiment and clicking the “Acquire” button. SpinFlow also caters for experienced users who may wish to alter the experimental parameters, or even write their own pulse sequences.
Once data collection is complete, the data is automatically transferred into Mnova, which has a full suite of advanced routines for processing and analysing NMR data. It also has a range of spectral display options including 2D and 3D stacking, which are particularly useful for reaction monitoring experiments.