Lc ms grade h2o

Chemicals used for the experiments were systematically of analytical grade or high-purity grade. Ultrapure water used to prepare buffers and sample solutions was obtained using a Milli-Q Reference A+ water purification system purchased from Merck Millipore (Billerica, MA, USA). LC-MS grade H₂O and acetonitrile (ACN) used for ultrahigh-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) experiments were purchased from VWR Chemicals (Fontenay-sous-Bois, France), respectively. Commercial products of infliximab innovator Remicade^® (Merck Sharp and Dohme) and the respective EMA/FDA-approved biosimilars Remsima^® (Celltrion Healthcare) and Flixabi^® (Biogen) were purchased from their respective manufacturers. Dithiothreitol (DTT) and iodoacetamide (IAM) were purchased from Sigma-Aldrich (Breda, the Netherlands). Trypsin enzyme was purchased from Promega (Madison, WI, USA).

Chemicals used were systematically of analytical grade or high purity grade. Ultra-pure water used to prepare buffers and sample solutions was obtained using a Milli-Q reference A + water purification system purchased from Merck Millipore (Billerica, MA). LC–MS grade H₂O and acetonitrile (ACN) used for UPLC-MS/MS experiments were purchased from VWR chemicals (Fontenay-sous-Bois, France). Hydropropyl methylcellulose (HPMC), ɛ-aminocaproic acid, triethylenetetramine (TETA), dithiotreitol (DTT), and iodoacetamide (IAM) were purchased from Sigma-Aldrich (Breda, The Netherlands). Trypsin enzyme was purchased from Promega (Madison, WI). The original products corresponding to the EMA/FDA-approved samples of mAb1 (mAb1 reference) and mAb2 (mAb2 reference) were provided by their respective manufacturer.