TL;DR: D-Fructose was analysed by NMR spectroscopy and previously unidentified (1)H NMR resonances were assigned to the keto and α-pyranose tautomers and there was a linear relationship between the change in concentration and temperature for all forms.
TL;DR: The above results are shown to be consistent with the proposal that polyproline I exists in aqueous solution as a right-handed helix with peptide bonds in the cis -configuration whereaspolyproline II exists inAqueous solutions as a left- handed helixWith peptide bond in the trans-configuration.
TL;DR: The loss of reducing sugars by formation of Schiff bases on amino-bonded silica or on dynamically coated amino-silica columns was investigated at two column temperatures, with coefficients of variation of less than 1% for the determination of lactose in skim-milk.