Amphetamine d5

The vials containing standards (1 mg/mL) for each analyte amphetamine and methamphetamine and their internal standards (amphetamine-D5 and methamphetamine-D5) were purchased from Lipomed AG (Cambridge, USA). Dichloromethane, isopropyl alcohol, ammonium hydroxide, methanol, acetic acid and acetonitrile were purchased from Sigma Aldrich (Germany). All chemicals were of HPLC grade. De-ionized (DI) water was prepared using Millipore purification system. SPE cartridges (CSDAU203) were purchased from United Chemicals Technologies (Philadelphia, USA).

Reference standards including the internal standards diazepam-d₅, morphine-d₆, methadone‐d₃, mianserin-d₃ and amphetamine-d₅ or MDMA-d₅ were purchased from Lipomed GmbH (Arlesheim, Switzerland), Cerilliant (Round Rock, TX, USA) or Toronto Research Chemicals (Toronto, ON, Canada). All reference standards were of ≥98% purity, as stated in the certificates. Acetonitrile (≥99.9%), methanol (≥99.9%), purified water, 2-propanol (≥99.5%) and ammonium formate (≥99.9%) were obtained from Fisher Scientific (Loughborough, UK) and were all LC–MS grade. Formic acid (98–100%) was purchased from Merck (Damstadt, Germany). Leucine enkephalin acetate was purchased from Sigma-Aldrich (St. Louis, MO, USA).

HPLC-grade solvents such as dichloromethane, isopropanol, hexane, ethyl acetate, acetic acid and methanol were obtained from BDH (Pool, UK). Ammonium formate was purchased from Sigma-Aldrich (Steinheim, Germany). All standards for meth, amphetamine, and their internal standards, including meth-D5 and amphetamine-D5, were purchased from Lipomed (Arlesheim, Switzerland). The Clean Screen DAU (200 mg) cartridges for solid-phase extraction (Part #CSDAU203) were acquired from United Chemical Technologies (Bristol, PA, USA).