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Table 2 Chemical shifts of peaks detected in P-NMR spectra

From: Characterizing the phosphorus forms extracted from soil by the Mehlich III soil test

Category P form or compound class Chemical shift (ppm)
Inorganic P
  Orthophosphate 6.00 ± 0.00
  Pyrophosphate − 4.06 ± 0.37
  Polyphosphates − 4.02 ± 0.32, − 4.89 ± 0.55, − 6.80 ± 0.79, − 8.95 ± 0.86, − 11.98 ± 0.83, − 16.68 ± 0.82, − 19.01 ± 0.89, − 20.99 ± 0.66, − 24.97 ± 0.74
Organic P
  Phosphonates 29.89 ± 0.75, 27.32 ± 0.67, 20.40 ± 0.10, 18.81 ± 0.19, 14.97 ± 0.48, 12.75 ± 0.70, 10.00 ± 0.95, 8.10 ± 0.23, 7.35 ± 0.17
Orthophosphate monoesters
  myo-IHP 5.49 ± 0.21, 4.56 ± 0.18, 4.16 ± 0.19, 4.06 ± 0.22
  scyllo-IHP 3.71 ± 0.17
  neo-IHP 6.43 ± 0.15, 4.26 ± 0.19
  d-chiro-IHP 4e/2a 6.59 ± 0.17, 5.29 ± 0.18, 3.96 ± 0.20
  d-chiro-IHP 4a/2e 6.21 ± 0.19, 4.84 ± 0.20, 4.31 ± 0.17
  Choline phosphate 3.85 ± 0.18
  Unknown 5.01 ± 0.15
  Monoester 1 6.86 ± 0.06, 6.69 ± 0.06, 6.37 ± 0.14, 6.24 ± 0.20
  Monoester 2 5.82 ± 0.07, 5.69 ± 0.08, 5.50 ± 0.17, 5.29 ± 0.12, 4.83 ± 0.14, 4.67 ± 0.15
  Monoester 3 3.71 ± 0.06, 3.53 ± 0.07, 3.32 ± 0.10, 3.12 ± 0.10, 2.96 ± 0.10, 2.72 ± 0.11
Degradation compounds
  α-Glycerophosphate 4.85 ± 0.02
  ß-Glycerophosphate 4.67 ± 0.02
  Mononucleotides 4.53 ± 0.06, 4.46 ± 0.11, 4.37 ± 0.14, 4.267 ± 0.14, 4.10 ± 0.12
Orthophosphate diesters
  DNA − 0.78 ± 0.26, − 0.91 ± 0.32
  Other diesters 2.35 ± 0.11, 1.96 ± 0.10, 1.55 ± 0.17, 1.15 ± 0.22, 0.65 ± 0.19, 0.33 ± 0.27, 0.07 ± 0.19, − 0.27 ± 0.20, − 0.57 ± 0.23, − 1.14 ± 0.21, − 1.52 ± 0.09, − 1.79 ± 0.13, − 2.15 ± 0.22, − 2.55 ± 0.23, − 3.01 ± 0.18, − 3.63 ± 0.21
  1. Peaks present in at least 10 of the 21 samples analyzed for the project, with all extractions grouped together
  2. IHP inositol hexakisphosphate, 4e/2a phosphates arranged in the 4-equatorial, 2-axial conformation, 4a/2e phosphates arranged in the 4-axial, 2-equatorial conformation
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