Recoveries and RSD of amphetamine drugs from aqueous samples.

Analyte	Concentration (ng mL−1)	Recovery (%, n = 5)	RSD (%, n = 5)
Amphetamine	5	73.4	6.88
	50	92.3	5.30
	150	91.6	1.65
Methamphetamine	5	82.6	6.11
	50	89.5	4.97
	150	95.4	1.38
3,4-Methylenedioxymethamphetamine	5	92.7	7.34
	50	94.7	6.32
	150	95.3	1.58