Determination of the Phenolic Composition and Antioxidant Activity of Pear Extracts

Table 2

Precision of the HPLC method for the quantitative determination of phenolic compounds.

Compound	Relative standard deviation (%) for the peak area
	Intraday			Interday
	1st concentration	2nd concentration	3rd concentration
Chlorogenic acid	0.33	0.89	3.39	4.48
Rutin	0.45	1.09	3.87	4.63
Hyperoside	0.33	0.4	0.46	3.4
Isoquercitrin	0.15	1.61	2.99	2.76
QMG	0.45	0.75	2.67	4.29
Isorhamnetin rutinoside	0.36	0.72	3.15	0.79
Quercitrin	0.65	0.52	2.53	1.16
Isorhamnetin glucoside	0.56	0.80	2.49	2.4

Repeatability. Intermediate precision.