Table 2.

Method performance of L-phenylalanine quantitation by circular dichroism.

Fixed concentration of internal standard			Variable concentration of internal standard
CL-phe [mg/g]	Bias [%]	RSD [%]	CL-phe [mg/g]	Bias [%]	RSD [%]
0.0049	−3.21	0.202	0.0049	2.85	2.203
0.0099	1.16	0.226	0.0099	2.24	0.596
0.0198	1.10	0.136	0.0198	0.82	0.264
0.0395	0.46	0.518	0.0396	0.73	0.266
0.0594	−0.59	0.386	0.0593	−0.25	0.182
0.0789	−0.62	0.157	0.0791	0.01	0.606
0.0990	−0.21	0.473	0.0990	−0.04	0.465
0.7940	−0.01	0.270	0.7919	0.27	0.481
0.9781	1.09	0.437	0.9899	2.15	5.468