title: Volume localized shift selective ¹³C spectroscopy using pulsed rotating frame transfer sequences with windows (PRAWN).
abstract: Some novel techniques for volume localized, chemical shift selective (13) C spectroscopy are described in this work. These techniques are based on rotating frame J cross polarization and are reported for both direct and indirect modes of (13) C detection. The performance of two selective mixing sequences, viz., pulsed rotating frame transfer sequences with windows (PRAWN) and PRAWN-π has been studied systematically with different liquid and gel phantoms. Two different front-end modules are used for volume localization, viz., point resolved spectroscopy (PRESS) and localized distortionless enhancement by polarization transfer (LODEPT). It is shown experimentally that both the selective J cross polarization sequences can operate efficiently with very low radiofrequency duty cycle; further, they have considerable tolerance to Hartmann-Hahn mismatch. A simple theoretical analysis is also presented to understand J cross-polarization dynamics at low RF field amplitudes. Finally, the performance of LODEPT-PRAWN-π is demonstrated for the selective detection of saturated fat in pigeon egg in indirect detection mode.
authors.affiliation: Department of Chemistry, Indian Institute of Technolog-Madras, Chennai, Tamil Nadu, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Banerjee
authors.forename: N
authors.initials: N
authors.lastname: Chandrakumar
mesh_terms: D000818:Animals; D002247:Carbon Isotopes; D010856:Columbidae; D004531:Eggs; D005227:Fatty Acids / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical
chemical_list: D002247:Carbon Isotopes; D005227:Fatty Acids