Quantification of molecules in (1)H-NMR metabolomics with formate as a concentration standard.

Quantitative analysis of metabolites is important in (1)H-nuclear magnetic resonance (NMR)-based metabolomics of plasma. Human plasma contains a high density of proteins which heavily adsorb the commonly-used standard compound of sodium 3-(trimethylsilyl) propionate 2, 2, 3, 3-d(4) (TSP). We have evaluated calcium formate as an alternative standard in 1D single-pulse (1)H-NMR spectra to quantify plasma metabolites. Formate did not interact with either plasma metabolites or proteins under adequate conditions. Linear relations between the signal intensities and the added formate have been demonstrated in (1)H spectra. The quantifications of glucose and creatinine by this method have shown good accordance with biochemical analysis. Calcium formate is applicable as a concentration standard to NMR metabolomics of plasma.