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. Author manuscript; available in PMC: 2010 Jun 15.
Published in final edited form as: Anal Chem. 2009 Jun 15;81(12):4847–4856. doi: 10.1021/ac9004875

Figure 1.

Figure 1

Typical 1H NMR spectra of control human urine samples containing: (A) no borate; (B) expansion of the region between δ1.1–1.4 from A; (C) the same sample with added 30.73 mM borate; (D) expansion of the region between δ1.1–1.4 from C. Peaks annotated “1” and “2” correspond to α-hydroxyisobutyric acid and methylmalonic acid, respectively, either free (in A and B) or in complex with borate (in C and D).