Lc grade ethanol

Purified water was obtained by using a Milli-Q Integral 3 system (Millipore SAS, Molsheim, France). Zomepirac sodium salt (used as internal standard, IS), L-pyroglutamic acid, hypoxanthine, L-histidine monohydrochloride monohydrate, oleic acid, L(+) lactic acid, LS-MS grade acetonitrile, methanol, formic acid, and LC grade ethanol were purchased from Sigma-Aldrich Chemie GmbH (Steinheim, Germany). The API-TOF reference mass solution kit (G1969-850001) and tuning solutions, ESI-L low-concentration tuning mix (G1969-85000), and ESI-TOF Biopolymer Analysis reference masses (G1969-850003) were purchased from Agilent Technologies (Santa Clara, CA, USA).

Purified water was obtained using the Milli-Qplus185 system (Millipore, Billerica, MA, USA). LC–MS grade methanol (MeOH), acetonitrile (ACN), formic acid and LC grade ethanol (EtOH), standard mix for GC–MS, containing grain fatty acid methyl ester mixture (C8-C28), 2-propanol and analytical grade heptane were purchased from Sigma-Aldrich ChemieGmbH (Steinheim, Germany). C18:0methyl ester and N,O-bis(trimethylsilyl) trifluoroacetamide with 1% trimethylchlorosilane were obtained from Pierce Chemical Co (Rockford, IL, USA). Silylation grade pyridine was purchased from VWR International BHDProlabo (Madrid, Spain). The API-TOF reference mass solution kit (G1969-850001) and tuning solutions, ESI-L low concentration tuning mix (G1969-85000) and ESI-TOF Biopolymer Analysis referencemasses (G1969-850003) were purchased from Agilent Technologies (Santa Clara, CA, USA).

Ultrapure water was used to prepare all the aqueous solutions and was obtained “in-house” from a Milli-Q Integral three system (Millipore, SAS, Molsheim, France). Zomepirac sodium salt, formic acid, LC-MS-grade methanol and acetonitrile, and LC-grade ethanol were purchased from Sigma-Aldrich Chemie GmbH (Steinheim, Germany).