Simultaneous Determination of Methamphetamine and Its Isomer N-Isopropylbenzylamine in Forensic Samples by Using a Modified LC-ESI-MS/MS Method

Table 4

The stability of MA and N-IBA under different conditions ().

Conditions	Samples	Compounds	Day 0 concentration (, ng/mL)	Measured concentration (, ng/mL)	RAD (%)
Autosampler for three days (15°C)	Suspect sample	MA			3.0
		N-IBA			0.4
	Mixed standard solution	MA			1.0
		N-IBA			0.7
Room temperature for one week (20°C)	Suspect sample	MA			0.1
		N-IBA			1.1
	Mixed standard solution	MA			1.5
		N-IBA			4.2
Freezer for 30 days (4°C)	Suspect sample	MA			2.4
		N-IBA			1.9
	Mixed standard solution	MA			3.7
		N-IBA			4.0