Simultaneous Determination and Stability Analysis of Ten New Psychoactive Substances including Synthetic Cathinones, Phenethylamines, and Ketamine Substitutes in Urine Using Liquid Chromatography-Tandem Mass Spectrometry

Figure 2

The stability of six synthetic cathinones in different matrices and temperatures. The stability of (a) 4-methylmethcathinone (mephedrone), (b) butylone, (c) pentylone, (d) eutylone, (e) N-ethylpentylone (ephylone), and (f) 4-methyl-α-ethylaminopentiophenone (4-MEAPP) in 50% methanol/water (50% MeOH), 50% methanol/water with 0.1% formic acid (50% MeOH in 0.1% FA), and urine at −20°C, 4°C, and 25°C.

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