Broadband 19F TOCSY using BURBOP-based spin lock

A train of BURBOP universal rotation pulses has been used to generate a spin lock sufficient to observe TOCSY correlations over a 46 kHz F-19 spectral window (i.e. 122 ppm on a 9.4 T spectrometer). This spin lock requires lower RF field (gamma B-1 = 15 kHz), and was employed over a wider spectral window, than previously reported DIPSI-2 spin locks. The BURBOP-based spin lock was effected for 80-160 ms periods with a 2% duty cycle without evidence of harm to the RF coil of the probehead. Spectral separation and full set of correlations were obtained for a mixture of perfluorocarbons. (C) 2017 Elsevier Inc. All rights reserved.