SPE-UHPLC-FLD Method for the Simultaneous Determination of Five Anthraquinones in Human Urine Using Mixed-Mode Bis(tetraoxacalix[2]arene[2]triazine) Modified Silica as Sorbent

Table 1

Analytical performance data of the proposed method.

Analyte	Calibration curves		Linear range	LOD	LOQ	RSD (%, )
			g mL^−1	ng mL^−1	ng mL^−1	Peak area	Retention time
Aloe-emodin		0.9997	0.012–1.200	4.1	12.1	2.35	0.38
Rhein		0.9995	0.018–1.800	5.7	18.2	2.21	0.42
Emodin		0.9996	0.015–1.500	5.1	15.2	1.84	0.29
Chrysophanol		0.9993	0.012–1.200	3.9	12.0	2.48	0.26
Physcion		0.9996	0.013–1.300	4.4	13.1	3.05	0.22