Table 4 Measured ratios of ¹⁵N/¹⁴N forms of metabolite fragment peaks in 1:1 mixtures of labeled and unlabeled extracts compared to their expected values. Expected ratios were calculated based on the fragment spectra ratios in the unmixed extracts (¹⁴N-extract, ¹⁵N-extract). The difference of the measured values to the expected values is expressed as percentage of the expected value.

From: Metabolic labeling of plant cell cultures with K¹⁵NO₃ as a tool for quantitative analysis of proteins and metabolites