Table 2.

Intra-day and Inter-day precisions and accuracies of theobromine and theophylline.

Analyte	Concentration (μg mL−1)	Intra-Day		Inter-Day
		Recovery (%)	RSD (%)	Recovery (%)	RSD (%)
Theobromine	10	96.74	2.06	94.34	1.31
	50	92.68	3.32	91.89	3.17
	100	90.37	4.19	89.96	3.94
Theophylline	10	95.79	2.15	93.96	2.07
	50	91.62	4.10	92.27	3.92
	100	89.13	3.36	87.72	4.03