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 4

Comparison of the stability of the analytes in urine at different temperatures. Stability of the 10 analytes in urine at (a) frozen temperature (−20°C), (b) refrigerated temperature (4°C), and (c) room temperature (25°C). The targeted concentrations for mephedrone, butylone, pentylone, eutylone, ephylone, 4-MEAPP, PMA, and PMMA are 50 ng/mL. The targeted concentrations for DCK and 2-FDCK are 25 ng/mL. Mephedrone: 4-methylmethcathinone; ephylone: N-ethylpentylone; 4-MEAPP: 4-methyl-α-ethylaminopentiophenone; PMA: para-methoxyamphetamine; PMMA: para-methoxymethamphetamine; DCK: deschloroketamine; 2-FDCK: 2-fluorodeschloroketamine.

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