Discrimination of parahydrogen induced polarization signals with J-spectra acquisition in poorly hyperpolarized samples

Abstract

The application of parahydrogen for the generation of hyperpolarization has increased continuously during the last years. When the chemical reaction that deposits the parahydrogen atoms into the target molecule is carried out following the PASADENA protocol an anti-phase signal is obtained, with a separation of the resonance lines of only a few Hz. Signal cancelation can be produced by line broadening due to magnetic field inhomogeneities or by the superposition with thermal signals. In this work we show that the acquisition of a J-spectrum has a double effect of enhancing spectral resolution and separating PHIP from thermal contributions even in systems where only a very small amount of hyperpolarization can be achieved.