Table 1.

Characters of established method.

	Intraday	Interday
Time (RSD%) (n = 6)	2.7	4.8
Area (RSD%) (n = 7)	2.2	4.9
Recovery (%)	0.5 μmol/L	5 μmol/L
	95%	112%
Linearity range (μmol/L)	0.05~10
Function and R 2	Area = 12.679 × Conc + 4.7555   R 2 = 0.9907
LOD (μmol/L)	0.03