Ferulic acidAdded (ng/ml) Stability Mean (ng/ml) SD RSD(%) RE (%) 5 5.09 0.46 9.1 1.9 500 432.51 9.80 2.3 -13.5 3000 3084.35 77.39 2.5 2.8

Ferulic acid standard solution at different concentrations of 5, 500 and 3,000 ng/ml in rat plasma was prepared, and then incubated at room temperature for 4 hours. The samples were then injected into UPLC-MS/MS to determine the stability of ferulic acid. Mean of the concentration (ng/ml) of ferulic acid in rat plasma, SD, RSD (%) and RE (%) was calculated, n = 3.

Table 4: Stability of the analysis of ferulic acid incubated in room temperature for 4 hours.