(b) HPLC calibration results for liquid-phase CC standard

Concentration	Loading	Peak area
(ng μL−1)	mass (ng)a	FA	AA	PA	BA	IA	VA
0.15	3	1,150,435	886,294	606,404	502,987	259,055	358,175
0.30	6	2,137,986	1,584,941	1,247,462	940,570	555,295	666,852
0.60	12	4,243,306	3,183,149	2,388,591	1,987,032	1,391,763	1,425,906
1.20	24	7,763,079	5,875,879	4,646,142	3,691,885	2,922,397	2,786,051
2.40	48	15,043,330	11,578,866	9,202,951	7,322,176	6,099,023	5,976,525

^aAldehyde/ketone-DNPH mix (Supelco): liquid phase standard is prepared to have equal mass for all target compounds per unit volume.