Mda d5

Pure MDMA, MDA and deuterated internal standards (MDMA-D5 and MDA-D5) were purchased from Cerilliant Corporation (Round Rock, TX, USA). Working solutions at concentrations of 0.5 mg/L and 5 mg/L were prepared in methanol and stored at -20ºC.
Methanol (gradient grade), HCl 37%, KH2PO4, dichloromethane, 2-propanol and NH4 + were purchased from Merck (Darmstadt, Germany). The derivatization reagent [MBTFA: N-Methyl-bis(trifluoroacetamide)] was purchased from Macherey-Nagel (Duran, Germany).
OASIS ® MCX columns were purchased from WATERS TM (Milford, MA, USA). The analytical apparatus included an Agilent 6890 GC, coupled to an Agilent 5973n MS.

High-purity (>97 %) standard solutions of the target compounds (METH, AMP, MDMA, MDA, KET, NK, COC, BE, Mor, Cod, MTD, EDDP, and 6-AM) and their deuterated analogues (METH-d8, AMP-d8, MDMA-d5, MDA-d5, KET-d4, NK-d4, COC-d3, BE-d3, Mor-d3, Cod-d6, MTD-d9, EDDP-d3, and 6-AM-d6) used as internal standards (purity >98 %) were purchased from Cerilliant (Round Rock, TX, USA). Individual stock solutions were prepared by diluting each analyte solution with acetonitrile (AcN) (HPLC grade, Fisher Science). Working standard mixtures were prepared at different concentrations by the appropriate dilution of the individual stock solutions with AcN. All of the stock and working standard solutions were stored in the dark at -20 °C. Highpurity water was prepared with a Milli-Q system (Millipore, MA, USA). Oasis MCX (60 mg, 3 mL) solid-phase extraction (SPE) cartridges were purchased from Waters Corporation (Milford, MA, USA). A CNW™ SPE vacuum manifold (CNW Technologies GmbH) was used for the SPE clean-up processes. Ammonium hydroxide (NH 4 OH) was purchased from Sinopharm Chemical Regent Co. Ltd. (Beijing, China). Ammonium acetate (HPLC grade) was obtained from CNW Technologies GmbH (Düsseldorf, Germany).