Quantification of AA
was performed using an external standard method. The curve for
AA in HPLC method was linear to atleast 300 lg/mL. In UPLC
method, lower concentrations must be used: a maximum concentration
cannot be higher than 50 lg/mL. The RSD values of the
standard curve slopes obtained with HPLC and UPLC systems were
2.78%, 1.82%, respectively. Linear correlation coefficients (r) for
both standard curves were 0.999.