Solid-phase service spectra are measured on Bruker AV600 spectrometer by a laboratory scientist. The instrument is equipped with different probeheads for analysis of liquid, semi-solid and solid samples, therefore the measurements requiring the corresponding appropriate probehead must be scheduled in advance.
Service analyses are requested via e-mail at email@example.com by completing the request form. For each sample a separate request form should be submitted. Please provide all the necessary information as indicated in the request form! The samples should be dry, well grinded to a fine powder and preferably in an Eppendorf tube. Given the specifics of sample preparation (direct contact with the substance under investigation and the possibility of inhaling fine particles), it is MANDATORY to indicate the POTENTIALLY DANGEROUS TO HEALTH samples.
The presence of paramagnetic atoms, as well as electrically conductive samples, MUST be indicated in the request form since these features affect the spectra and in extreme cases can damage the NMR spectrometer.
The service analyses of solid state samples are performed with the 4mm CP MAS probehead using 4mm (outer diameter) rotors of 80 microliters. The recommended amount of sample is 200-250 mg, taking into account possible losses when filling the rotor.
The NMR service analyses in solid phase include the following nuclei: 13C, 31P, 15N, 7Li, 6Li, 11B, 29Si, 27Al, 23Na. Spectra with 1H®X cross-polarization or high power proton decoupling (HPDEC) could be registered for some nuclei (X = 13C, 31P, 15N, 29Si).
The service analyses in semi-solid (soft) phase are performed with 4mm 1H/13C/31P HR MAS probehead using 4mm (outer diameter) rotors of 80 microliters. The recommended amount of sample is 50-100 mg, soaked in appropriate deuterated solvent. The typical 1D and 2D homo- and heteronuclear (13C, or 31P) experiments available for liquid state samples are generally applicable also for semi-solid (soft) materials.
For more details regarding the NMR service analyses in solid and semi-solid phase, please contact the Head of the Bulgarian NMR Centre prof. Pavletta Shestakova at the following e-mail: Pavletta.Shestakova@orgchm.bas.bg