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Amino acids are effective tracers of organic carbon and nitrogen cycling in natural substrates. However, total analytical time can be long due to extraction, derivatization, and chromatography. Here, we present a liquid chromatographic separation of 19 naturally occurring amino acids requiring no derivatization using triple-quadrupole mass spectrometry. This method builds on recent advances in volatile ion pairing and was applied to natural soil samples collected from two distinct systems with highly variable organic C contents. Separation and quantification of amino acids were achieved with an 18 min sample-to-sample run time employing a one-point standard addition to account for variable matrix effects during ionization. Detection limits ranged from 5.9 to 187.5 fmol (mean 30.0 fmol) while instrumental precision averaged 5.8% and 12.0% for intra- and inter-day error, respectively. The highest yields (mean > 100 …