The Sirchie NARK II Sodium Nitroprusside Reagent is designed to color react with the secondary amines present in both Methamphetamine and MDMA (Ecstasy). This presumptive field test will develop an immediate (within 2 seconds) dark purple or dark blue color as a positive reaction after breakage and agitation of the 3rd ampoule. If the color development is an immediate pink slowly transforming to lavender, you do not have either Methamphetamine or MDMA. This color reaction suggests you should proceed to the #NARK2001 Marquis Reagent for either Amphetamines or analogs of MDMA (referred to as Letter Drugs). Like all NARK II narcotic field tests, the Sodium Nitroprusside Reagent is meant for presumptive field drug testing.