Determination of Caffeine Content in Commercial Energy Beverages Available in Saudi Arabian Market by Gas Chromatography-Mass Spectrometric Analysis

Table 1

Precision and accuracy results for intraday and interday analysis of caffeine by the proposed method.

	Concentrations of solutions (μg/mL)	% RSD of peak areas (n = 3)	% RSD of retention times (n = 3)	% recovery (n = 3)
Intraday analysis	5 (LQC)	0.57	0.82	98.3
	10 (MQC)	0.84	0.59	100.6
	20 (HQC)	0.69	0.87	98.4
Interday analysis	5 (LQC)	0.81	0.92	99.1
	10 (MQC)	0.74	0.68	98.6
	20 (HQC)	0.66	0.88	98.8

^∗LQC, MQC, and HQC are low-, medium-, and high-quality control samples.