Quantification of Caffeoylquinic Acids in Coffee Brews by HPLC-DAD

Table 2

Validation parameters for CQAs analysis by HPLC-DAD.

Validation; parameters	Concentration; levels^a	3-CQA	4-CQA	5-CQA
Linearity range (mg/L)	—	2–400	1–200	1–200
()^b	—	0.999	0.999	0.999
Sensitivity^c	—	116292	122162	111337
Limit of detection (mg/L)^d	—	0.37	0.39	0.18
Limit of quantification (mg/L)^d	—	1.24	1.29	0.58
Intraday precision (%CV)	C1	1.06	0.95	0.36
	C2	1.06	0.80	0.54
	C3	0.31	0.17	0.24
Interday precision (%CV)	C1	0.81	0.54	0.36
	C2	0.46	0.68	0.23
	C3	1.11	1.41	0.32

Concentration of each compound in standard solutions was as follows. C1: 3-CQA (40 mg/L), 4-CQA (20 mg/L), and 5-CQA (20 mg/L); C2: 3-CQA (160 mg/L), 4-CQA (80 mg/L), and 5-CQA (80 mg/L); C3: 3-CQA (320 mg/L), 4-CQA (160 mg/L), and 5-CQA (160 mg/L).
coefficient of determination, number of calibration curve standards.
^cSensitivity was expressed as the slope of the calibration curves.
^dCalculated from the signal to noise ratio of 3 (LOD) and 10 (LOQ).