Qma light and c18 light sep paks

Unless otherwise stated, reagents and solvents were commercially available and used without further purification. Hospira sodium chloride, 0.9% USP, and sterile water for injection, USP, were purchased from Pfizer (Lake Forest IL, USA). Ethanol was purchased from American Regent (Shirley NY, USA). HPLC grade acetonitrile was purchased from Fisher Scientific (Waltham MA, USA). Other synthesis components were obtained as follows: sterile filters were obtained from MilliporeSigma (Burlington MA, USA); sterile product vials were purchased from Hollister-Stier (Spokane WA, USA); QMA-light and C18-light Sep-Paks were purchased from Waters Corporation. Sep-Paks were conditioned with ethanol (10 mL), followed by water (10 mL) prior to use. QMA cartridges were conditioned with 10 mL each of ethanol, 0.5 M NaHCO₃ and, lastly, Milli-Q water prior to use.