Table 1: Recoveries and precision of QC samples ( ).

MetaboliteAdding amount ( M)Detection value ( M)Average recovery (%)RSD (%)

Arginine20.016.0, 17.0, 18.085.005.88
50.043.0, 44.0, 46.088.703.45
80.068.0, 71.0, 73.083.332.29
Histidine20.014.0, 15.0, 16.075.006.70
50.043.0, 44.0, 45.088.002.27
80.062.0, 65.0, 67.080.803.89
Aspartate20.014.0, 15.0, 15.073.333.94
50.039.0, 41.0, 42.081.333.76
80.063.0, 65.0, 68.080.832.36
Lactic acid20.015.5, 16.0, 17.381.335.71
50.042.6, 44.2, 43.086.531.92
80.068.5, 72.4, 70.287.962.78
Citric acid20.013.6, 14.5, 15.071.834.94
50.039.4, 41.6, 43.082.674.39
80.068.3, 70.5, 74.088.674.05