Piperaquine tetraphosphate tetrahydrate

Piperaquine tetraphosphate tetrahydrate (MW 999.55, purity 99%) was purchased from AK Scientific, Inc. (CA, USA). Piperaquine-d₆ (PQ-d₆, MW 541.55, isotopic purity ≥99%) was purchased from AlSAchim, SAS (IllKirch, France). Trichloroacetic acid (TCA) and ammonium formate (NH₄FA) (certified ACS reagents), trifluoroacetic acid (TFA) and formic acid (FA) (Optima™ LC/MS grade), acetonitrile (MeCN), methanol (MeOH) and other common solvents (HPLC grade) were purchased from Fisher Scientific, Inc. (NJ, USA). Blank human plasma (K₃EDTA added as anticoagulant) was obtained from Biological Specialty Corporation (PA, USA).

Piperaquine tetraphosphate tetrahydrate (MW 999.55, purity 99%) was purchased from A.K.Scientific Inc. (Union City, CA, USA). The internal standard (IS) piperaquine-d₆ (PQ-d₆ , MW 541.55, isotopic purity ≥ 99%) was purchased from AlSAchim, SAS (IllKirch, France). Benzalkonium chloride (BAK) was obtained from Alfa Aesar Co. Trifluoroacetic acid (TFA) and formic acid (FA) (Optima™ LC/MS grade), acetonitrile (MeCN), methanol (MeOH), and other common solvents (HPLC grade) were purchased from Fisher Scientific Co. (Fair Lawn, NJ, USA). Blank human plasma (K₂EDTA added as anticoagulant) was obtained from Biological Specialty Co (Colmar, PA, USA); 10% MeCN 0.5% FA solution was prepared by adding 5 mL MeCN and 250 μL FA to 45 mL water (HPLC grade). Mobile phase A (20 mM NH₄FA, 0.14%TFA) was prepared by adding 1.262 g NH₄ FA and 1.4 mL TFA in 1 L water. Mobile phase B (0.1%TFA) was prepared by mixing 200 mL MeCN, 800 mL methanol and 1 mL TFA in 1 L glass bottle.