Cross polarization-single pulse/magic angle spinning (CPSP/MAS): A robust technique for routine soil analysis by solid-state NMR

摘要: Soils are amongst the largest organic carbon reservoirs on earth containing approximately three times contained in all living systems and roughly double amount present atmosphere. Soil matter is central to agriculture, cycling, contaminant sequestration, but due its extreme heterogeneity it challenging study with most modern analytical approaches. As such 13C NMR spectroscopy has emerged as an indispensable technique for characterization of soil solid-state. Single pulse (SP) approaches theoretically provide highest level quantitation matter, however, relative insensitivity, sample analysis can take a prohibitively long time. Consequently, routine studies more sensitive approach cross-polarization under magic angle spinning conditions (CP/MAS) commonly utilized. In particular, CP extremely useful when low content samples compared normally used reveal nature, transformations fate soils. Here, performance novel scheme, which so far not yet been applied soils samples, investigated. The ramp-CPSP scheme adds SP block ramp-CP taking advantage both techniques without extending experimental This method shows enhancements higher than 100% key regions spectra also provides profiles that closer quantitative widely scheme. addition, critical these presented. Even worst case scenario, element little additional signal, result still reflects conventional experiment. be implemented fashion drawback. results shown here suggest replacing sequence solid-state since save considerable time representative spectrum general.