title: NMR-Based Chemosensing via p-H2 Hyperpolarization: Application to Natural Extracts.
abstract: When dealing with trace analysis of complex mixtures, NMR suffers from both low sensitivity and signal overlap. NMR chemosensing, in which the association between an analyte and a receptor is "signaled" by an NMR response, has been proposed as a valuable analytical tool for biofluids and natural extracts. Such chemosensors offer the possibility to simultaneously detect and distinguish different analytes in solution, which makes them particularly suitable for analytical applications on complex mixtures. In this study, we have combined NMR chemosensing with nuclear spin hyperpolarization. This was realized using an iridium complex as a receptor in the presence of parahydrogen: association of the target analytes to the metal center results in approximately 1000-fold enhancement of the NMR response. This amplification allows the detection, identification, and quantification of analytes at low-micromolar concentrations, provided they can weakly associate to the iridium chemosensor. Here, our NMR chemosensing approach was applied to the quantitative determination of several flavor components in methanol extracts of ground coffee.
authors.affiliation: Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Niels K J
authors.initials: NK
authors.lastname: Hermkens
authors.affiliation: Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Nan
authors.initials: N
authors.lastname: Eshuis
authors.affiliation: Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Bram J A
authors.initials: BJ
authors.lastname: van Weerdenburg
authors.affiliation: Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Martin C
authors.initials: MC
authors.lastname: Feiters
authors.affiliation: Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Floris P J T
authors.initials: FP
authors.lastname: Rutjes
authors.affiliation: Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Sybren S
authors.initials: SS
authors.lastname: Wijmenga
authors.affiliation: Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Marco
authors.initials: M
authors.lastname: Tessari
mesh_terms: D001688:Biological Products / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
chemical_list: D001688:Biological Products